Dissertation Finished

BSc(Hons)Sport & Exercise Science Ryan Till66-6920-00L-A-20145 Project 22008862

Table of ContentsAcknowledgements 3

Abstract 3

CHAPTER 1: Introduction 4-5

CHAPTER 2: Literature Review 4-16

2.1 The causes of Muscle Damage which results in DOMS 4

2.2 Mechanically Induced Muscle Damage 5

2.3 Metabolically Induced Muscle Damage 6

2.4 Tart Cherries Mechanism of Action 7

2.5 Clinical Practice to Sport Science 7

2.6 The Effects of Tart Cherries on Muscular Performance 8

2.7 The Effects of Tart Cherries on Muscle Damage 9

2.8 Inflammation 10

2.9 Oxidative Stress 12

2.10 Perceived Muscle Soreness13

2.11 Dosage Strategy 14

2.12 Participants 15

2.13 Hypothesis16

CHAPTER 3: Methods 17-21

3.1 Participants 17

3.2 Experimental Design 17

3.3 Nutritional Supplements 17

3.4 Experimental Protocol 18

3.5 VAS Questionnaire 19

3.6 Serum CK Blood Analysis 20

3.7 Isokinetic Dynamometer 20

3.8 Data Collection/Analysis 20

CHAPTER 4: Results 22-26

4.1 Delayed Onset Muscle Soreness 22

4.2 Maximum Voluntary Contraction 24

4.3 Creatine Kinase 25

CHAPTER 5: Discussion 26-33

5.1 Functional Recovery 26

5.2 Perceived Muscle Soreness 30

Faculty of Health and Wellbeing Sheffield Hallam UniversityPage 1


5.3 Limitations 31

CHAPTER 6: Conclusion 33

CHAPTER 7: References 34-40

APPENDICES 1. Progress Record Form 41

2. Participant Information Sheet 43

3. Medical Health Questionnaire 46

4. Informed Consent Form 49

5. VAS Questionnaire ……………………………………………………………………………………………….. 50

6. Risk Assessment Form 52

7. Ethics Forms ……….……………………………………………………………………..………………………… 55



The effects of tart cherry supplementation on muscle damage, muscle force regeneration

and perceived muscle soreness in untrained males and females following isokinetic

dynamometry

i. Acknowledgments

I would like to thank the participants who actively engaged in the present study. I also wish

to extend my gratitude to Sheffield Hallam University, for the use of their laboratory facilities

and to the physiology laboratory technicians for their technical support during the

investigation. Finally I would like to thank Dr Mark Hopkins for academic support and

guidance throughout the course of the project.

ii. Abstract

Background: Tart cherries phytochemical content namely, anthocyanins and flavonoids

elicit potent antioxidant and anti-inflammatory effects. By increasing antioxidant defence

systems and reducing inflammation it’s believed we can accelerate muscle function recovery

and reduce perceived pain following exercise induced muscle damage. Objective: previous

research into tart cherries have shown positive effects in speeding up the recovery process

in well-trained/recreationally active individuals. Therefore, we aimed to investigate whether

these effects would be identical when tested using untrained participants. Methods: 6

untrained participants completed two trials, consisting of 5 sets of 12 maximal eccentric

hamstring contractions on an isokinetic dynamometer (60 -secˉ¹). Trials were separated by a⁰

6 day wash out period. Participants consumed each supplement (Cherry Active or Cherry

Cordial) 5 days pre, on the day and 2 days post. CK was measured before and 48 hours

post-exercise, MVC was measured before, after and 48 hour post-exercise whilst a VAS was

given before, after and 24-72 hours post-exercise. Results: No significant differences were

seen between conditions on measures of CK or MVC, but clear trends of reduced CK and

accelerated force regeneration were seen in the tart cherry group 48 hours post exercise.

CK: (78% vs 340% of pre-ex values, MVC: (91% vs 80% of pre-ex values). Perceived

soreness of the hamstring group was significantly reduced in the tart cherry condition,

compared to the placebo (P = 0.045) whilst there was also a significant time*condition

interaction effect (P = 0.006). Conclusion: The consumption of 2 tart cherry drinks per day

(~90-100 cherries) decreased perceived muscle soreness and identified trends of reduced

muscle damage (CK) and accelerated muscle force recovery in untrained participants which

may be due to the phytochemical content of cherries reducing oxidative stress and tissue

damage whilst blunting the inflammatory response to muscle damage and exercise.

Keywords: Maximum Voluntary Contraction (MVC), Creatine Kinase (CK), Visual Analog

Scale (VAS).Faculty of Health and Wellbeing Sheffield Hallam University

Page 3


1. Introduction

Delayed onset muscle soreness is prevalent throughout each extreme of the performance

pyramid with both well trained and novice performers experiencing the delayed soreness

post exercise bout (Cheung et al. 2003). Whilst it’s difficult to obtain statistics on the

incidence of delayed onset muscle soreness due to the majority of individuals not seeking

medical attention (Kedlaya, 2014) it is however, more prevalent following eccentric exercise

(Cheung et al. 2003).

Exercise induced muscle damage following an unaccustomed bout of exercise is caused by

inadequately conditioned skeletal muscle which leads to injury within the muscle fibres;

typically after a bout of eccentric exercise (Armstrong et al. 1991). The structural damage

often results in pain or soreness, which has been termed Delayed Onset Muscle Soreness

(DOMS) (Kuipers, 2008). Delayed onset muscle soreness results in a loss of contractile

force (Hamlin and Quigley, 2001) which may be due to the loss of Creatine Kinase (CK) and

the release of inflammatory enzymes (Haramizu et al. 2011). Other consequences of DOMS

include negative impacts on performance due to impaired motor control, negatively

impacting sense of position, co-ordination and as a result performance (Serinken et al. 2013)

whilst muscle glycogen storage is reduced in muscles damaged through eccentric exercise

when compared to limbs not exercised (Costill et al. 1990).

DOMS is suggested to be caused by the inflammation response to muscle damage and can

last for up to 96 hours, with levels of soreness suggested to peak by 48 hours (Connolly et

al. 2003). The hypothesis used to explain the formation of muscle damage has been

attributed to either mechanical or metabolic causes (Armstrong et al. 1991, Tee et al. 2007,

Kuipers, 2008, Penailillo et al. 2013). The mechanical cause has being more widely

accepted but neither hypothesis has been characterised sufficiently (Tee et al. 2007). The

mechanical cause of muscle damage attributes the structural damage to high tension

contractions which cause the myofibril to tear and calcium to flood into the tissue causing

inflammation (Morgan and Proske, 2004). The metabolic cause of muscle damage on the

other hand, suggests muscle damage occurs from a cascade of events whereby adenosine

triphosphate (ATP) and glycogen stores are depleted leaving muscles more vulnerable to

mechanical muscle damage whilst also being exposed to greater Reactive Oxygen Species

(ROS) which scavenge electrons from local tissues which cause muscle damage (Tee et al.

2007).



Supplementation with functional foods has become increasingly popular due to evidence

indicating that such food or supplements may speed up the recovery process (Bell et al.

2014a). Cherries have lately been of debate on their effectiveness on a variety of conditions

from enhanced sleep through elevating melatonin (Howatson et al. 2012), to inflammation

conditions of the body’s tissue (Jacob et al. 2003, Kelley et al. 2006; Kelley et al. 2013). Tart

cherries are of interest due to their high antioxidant content and anti-inflammatory properties.

Wang et al. (1999), identified cherries had similar antioxidant activity to commercial

antioxidants and had greater anti-inflammatory effects than aspirin. It is proposed that tart

cherry supplementation blunts the primary and secondary response to muscle damage

associated with inflammation, following the initial onset of muscle damage suspected to be

caused by the previously discussed mechanical and metabolic processes; whilst improving

antioxidant defence systems to neutralise Reactive Oxygen Species (ROS) (Bell et al.

2014b). Previous research using tart cherry supplementation has found beneficial effects on

DOMS following long distance running (Kuehl et al. 2010) and muscle force regeneration

following eccentric resistance training (Connolly et al. 2006; Bowtell et al. 2011) .

However, no study currently exists which focuses specifically on the effects of tart cherry

supplementation on untrained subjects. As a result, these positive results may have been

found because the participants were accustomed and protected from the damage of

eccentric contractions due to, regular training causing adaptations in sarcomere lengths

(Morgan and Proske, 2004). Furthermore, it is important to focus on untrained individuals for

numerous reasons such as; pain being a common barrier to exercise and causing avoidance

behaviour (Letham et al. 1983; Dalle-Grave et al. 2010) and the poorer antioxidant defence

system in inactive individuals (Kruk, 2011). Therefore, this study aims at investigating

whether tart cherry supplementation produces desirable effects on; subjective ratings of

muscle soreness, muscle force regeneration and CK markers of muscle damage in an

untrained population, following unaccustomed eccentric exercise in the lower extremities.

2. Literature Review

2.1 The causes of muscle damage which results in DOMS.

Muscle damage and inflammation, connective tissue damage, lactic acid accumulation and

enzyme efflux theories are the potential mechanisms which cause DOMS (Cheung et al.

2003). However, theories such as the lactic acid accumulation have found limited success in

explaining DOMS, whilst it’s generally accepted muscle damage is the main cause of

DOMS, but a combination of all theories may best explain DOMS (Gulick and Kimura, 1996).

As briefly discussed structural damage of the muscle fibre, which commonly occurs following



a bout of eccentric exercise causes the formation of pain 1-5 days post exercise (Armstrong,

1984) which may be due to the inflammation phase of muscle recovery (Liu et al. 2006). The

process in which muscle damage occurs has been associated with both mechanical and

metabolic stress models which are outlined below.

2.2. Mechanically induced muscle damage

Mechanically induced muscle damage occurs due to muscle fibres weakening. Human

motion consists of two types of contractions which co-exists; these include eccentric

contractions and concentric contractions (Tee et al. 2007). Therefore, when exercise is

manipulated to be completely eccentric it is no surprise muscle damage is observed as it’s

been demonstrated several or single bouts of eccentric contractions result in micro-injury

(Cheung et al. 2003) caused by the stress in the fibre being greater than the components

strength (Armstrong et al. 1991). This causes the contractile proteins to fail due to excessive

force on the cross-bridges (Tee et al. 2007). Morgan and Proske (2004) proposed a popping

sarcoplasm hypothesis, suggesting when sarcomeres are stretched to points in which are

beyond optimum length, it would result in damage to the sarcomere due to it being stretched

more rapidly. Due to the weakest sarcomeres being at different points of each myofibril, the

eccentric nature of the stretch results in tears of the myofibril and these tears result in an

increase in calcium which causes a pro-inflammation response (Morgan and Proske, 2004).

However, it is important to note that stretches 50% of optimum length have resulted in

increased calcium concentration yet with no damage to the surface membrane, suggesting

the muscle may not always be structurally damaged when inflammation occurs (Butterfield,

2010). Liu et al. (2006) proposed a three phase hypothesis of DOMS composed of the

stages; inflammation, proliferation and maturation. It was suggested inflammation occurred

0-5 days post muscle damaging exercise and as a result, may infer muscle damage and

inflammation is the predominant cause of DOMS as pain is typically felt 1-5 days post

exercise (Connolly et al. 2003).

2.3. Metabolically induced muscle damage

Insufficient mitochondrial respiration and free radical production are hypothesised to be

attributing factors to metabolically induced muscle damage (Armstrong et al. 1991). Whilst

exercising humans switch through the various energy systems to produce the equivalent

adenosine triphosphate (ATP) to the amount of ATP expended during activity. Therefore Tee

et al. (2007) suggests it is possible that muscle damage can be a direct effect of insufficient

amounts of ATP, especially when coincided with severe glycogen depletion due to a

reduction of high energy phosphates during muscular contractions, which may create a

vulnerability to mechanical muscle damage, or increase the cellular damage due to the Faculty of Health and Wellbeing Sheffield Hallam University

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greater consumption of oxygen resulting in an increased number of reactive oxygen species

(ROS) (Kruk, 2011). These ROS readily oxidize with lipid molecules and can cause tissue

damage when overcoming antioxidant defence systems (Mylonas and Kouretas, 1999).

Therefore, an increased number of ROS following exercise would equate to greater muscle

damage. Tee et al. (2007) elicited on a final mechanism which could potentially explain

metabolic muscle damage in the absence of mechanical stress through the reduction in

activity of adenosine triphosphatase which prevents the removal of calcium causing muscle

fibre damage and inflammation. However, like the mechanical stress model the metabolic

stress model is not without its limitations, as eccentric contractions have a reduced cost of

ATP when compared with concentric contractions, yet seem to significantly induce greater

muscle damage (Tee et al. 2007). As a result, a combination of both models may best

explain muscle damage, whilst these micro-injuries and the inflammation response to these

injuries may best explain the DOMS phenomenon (Gulick and Kimura, 1996).

2.4. Tart Cherries Mechanism of Action

Tart cherries also known as sour cherries or Prunus cerasus L have been of interest due to

their high phytochemical contents such anthocyanins which have seen values as high as

80.4 mg/100g in tart cherries (Blando et al. 2004). Anthocyanins and quercetin content of tart

cherries is known to inhibit cyclooxygenase (COX) found responsible for the inflammation

response, whilst the flavonoid content has been shown to reduce oxidative stress (McCune

et al. 2011). As previously discussed the causes of DOMS are suspected to be associated

with muscle damage and inflammation (Cheung et al. 2003). Therefore, tart cherries may be

a suitable supplement to use to prevent DOMS and muscle damage due to the anti-

inflammatory properties to supress the inflammation stage which occurs 0-5 days following

muscle damage (Liu et al. 2006) which is commonly associated with muscle soreness

(Connolly et al. 2003). Furthermore, tart cherries may improve the antioxidant defence

systems due to the anthocyanin and flavonoid content which may reduce the extent of

muscle damage through metabolic stress by neutralising ROS. The most recent proposed

mechanism of tart cherries is that it improves antioxidant defences, which leads to a

reduction in cell damage following metabolically induced muscle damage and therefore, less

primary and secondary inflammation (Bell et al. 2014b). Subsequently tart cherries are

suggested to blunt the secondary inflammation response and reduce the oxidative stress in

exercise high in mechanical stress and low in metabolic stress (Bowtell et al. 2011).

Therefore, if there is less overall damage or a decrease in inflammation it would be feasible

to suggest; there would be a decrease in serum CK, muscle pain would be significantly



reduced and as a direct result muscular performance in terms of force production would

remain closer to baseline levels.

2.5. Clinical practise to Sport Science

Tart cherry supplementation was originally tested and used in clinical application (Bell et al.

2014a). Jacob et al. (2003) investigated the effects of cherry supplementation on uric acid in

healthy women which lead to the conclusion that adopting a dietary intake of 45-50 cherries

per day, in which the cherries were consumed in under 10 minutes was successful in

decreasing uric acid production by 14.5%. This is of importance as uric acid has been

identified to cause inflammatory conditions such as gout (Zhang et al. 2012) and suggests a

role for tart cherries in decreasing uric acid and subsequent inflammation. However, Jacob

et al. (2003) failed to establish a placebo group, whilst the control of the study was lost after

3 hours where participants were free to do as they wished before returning on the 5th hour for

more post measures. As a result, it is possible participants may have consumed extra

sources of antioxidants and anti-inflammatories over estimating the ability of cherries.

Furthermore with the participants being healthy, the results cannot be readily generalised to

patients with inflammatory conditions. However, this initial research into cherries reinforced

the original work by Wang et al (1999) who identified in vitro that the phytochemicals in

cherries such as the anthocyanins and flavonoids were successful in preventing

inflammation enzymes (cyclooxygenase) and reducing oxidative stress. As a direct result of

the positive findings in clinical application, tart cherries have more recently become popular

in the sport science domain due to the antioxidant properties and anti-inflammatory affects

originally discussed by Wang et al. (1999). It is hypothesised that tart cherries will be of

benefit in sport specifically to reduce muscle damage and muscle pain following a bout of

vigorous exercise by reducing oxidative tissue damage (metabolic muscle damage) whilst

reducing the inflammatory response to muscle damage which occurs following eccentric

exercise (mechanical muscle damage) (Connolly et al. 2003). Therefore, if the muscle is

protected from damage and pain is supressed we would expect muscle function to remain

around a normal capacity.

2.6. The Effects of Tart Cherries on Muscular Performance

The evidence on muscle force regeneration following tart cherry supplementation has been

positive in the three studies which have measured muscular performance. Connolly et al.

(2006) was first to identify supplementation over a period of 9 days with 2 cherry drinks per

day, which consisted of approximately 45-50 cherries, was successful in maintaining muscle

function. Connolly et al (2006) identified only a 4% reduction in muscle strength in the tart

cherry group in comparison to a 22% reduction in the placebo group following maximum Faculty of Health and Wellbeing Sheffield Hallam University

Page 8


eccentric contractions of the elbow. However, they found no difference in range of

movement and muscle tenderness between the placebo and tart cherry group, which infers

muscular strength may be the greatest variable to measure. Consistent with these findings,

Bowtell et al. (2011) also found that tart cherry may speed up the recovery of muscle

function. Bowtell et al. (2011) adopted a different dosage strategy opting to use a 10 day

supplementation period; 7 days loading, on the day of exercise and 2 days post, with 2

drinks consumed a day. Bowtell et al. (2011) found that tart cherry supplementation

significantly attenuated strength loss, as Maximum Voluntary Contraction (MVC) was 6%

closer to baseline MVC levels in the cherry group when compared to the placebo after 24

hours whilst also being closer to normal after 48 hours (92.9% vs 88.5%) following knee

extension exercises and MVC to induce muscle damage. However, both studies have the

same methodological limitation of utilizing a cross over design where by participants

complete both conditions and as a result are subject to the repeat bout effect. The repeated

bout effect creates a protective effect following a single bout of exercise, which may be due

to; cellular adaptations which make the surface membrane greater resistant to future

damage (Howatson et al. 2007) or through increased recruitment of muscle fibres (Tee et al.

2007). Furthermore, both Connolly et al. (2006) and Bowtell et al. (2011) failed to gain strict

control on diet and physical activity suggesting any positive results in strength regeneration

may have been down to differences in diet or training from one trial to the other. However,

the significant findings from these studies infer tart cherry supplementation may be beneficial

in speeding up the recovery process and maintaining muscle function close to normal values

following muscle damaging exercise. With muscular strength being proposed to be the most

accurate indirect marker of muscle damage (Xin et al. 2014) it suggests that tart cherry

supplements may effectively speed up the recovery process and prevent a greater extent of

muscle damage. It is important to note, the previously mentioned studies showed force

regeneration following eccentric resistance training consisting of high mechanical stress and

low metabolic stress (Connolly et al. 2006; Bowtell et al. 2011). Unlike Connolly et al. (2006)

and Bowtell et al. (2011), Howatson et al. (2010) induced muscle damage through the

mechanical and metabolic stress processes during marathon running and like the

aforementioned studies also found greater force regeneration when compared to a placebo,

identifying muscle force was back to normal values after 48 hours in the tart cherry condition

whereas, the placebo group was still recovering after the 48 hour mark. From the growing

base of literature we can conclude; tart cherry supplementation may offer beneficial effects

in speeding up the recovery of muscular force following muscle damaging exercise.

2.7. The Effects of Tart Cherries on Muscle Damage



The literature on the effects of tart cherry supplementation on serum creatine kinase (CK)

markers of muscle damage have demonstrated slight improvement when supplementing tart

cherry in comparison to a placebo. Howatson et al. (2010) initially demonstrated that 20

marathon runners who completed the London marathon following an 8 day supplementation

period (5 day prior to the marathon, on the day and 2 days post), consuming approximately

100-120 cherries per day had lower values of CK than those in the placebo group at 24 and

48 hour post marathon. Whilst the values did not meet statistical significance they still

demonstrated tart cherry may have had an effect on attenuating serum CK, as CK was 23%

(at 24 hours) and 28% (at 48 hours) lower in the cherry group when compared to placebo. In

addition, Bell et al. (2014b) identified attenuated CK 48 hours post repeated sprint cycle

exercises in 16 well trained participants who consumed tart cherries when compared with

placebo. There was a significant 42% decrease in CK from placebo to tart cherry and more

importantly the values of CK 48 hours after exercise were now lower than initial baseline

measurements. However, both of the studies adopted an independent measures design.

Therefore, any change observed may be due to individual physiological differences, as some

individuals may be trained and adapted better to eccentric exercise than others (Morgan and

proske, 2004). Whilst it’s also been demonstrated that different individuals of similar age and

training status doing the same exercise produce different amounts of CK (Baird et al. 2012).

In contrast to the aforementioned studies, Bowtell et al. (2011), adopted a cross over design

using the same 10 well trained participants in each testing condition and found no significant

difference between trials and unlike the previous studies identified an overall trend of CK

activity being greater during the tart cherry trial following eccentric knee extension exercises

at 80% of the participants 1RM. Therefore, from Bowtell et al. (2011) findings we could

conclude that tart cherry supplementation has no significant effect on serum CK. However,

the use of CK as an indirect marker of muscle damage is highly debated. Baird et al. (2012)

discuss how CK may leave muscle cells to allow for a regeneration period and may not be

strictly associated with physical/structural damage but instead a restriction in energy

processes. Therefore, unlike MVC, CK may not be the greatest indirect marker of muscle

damage to be used. However, currently only one study using tart cherry supplementation

has found increased levels of CK following eccentric resistance training of the knee flexor

(Bowtell et al. 2011).

2.8. Inflammation

The phytochemicals which exist in tart cherries; specifically the anthocyanin and flavonoid

content have been studied in vitro (Wang, 1999) and in healthy females (Jacobs et al. 2003)

and found to have anti-inflammatory effects. Cherries are suggested to have one of the



greatest concentration of flavanols and quercetin (Bentz, 2009). Studies on quercetin

indicate it has a long half-life ranging from 3 hours (Moon et al. 2008) to 11-28 hours

(Manach et al. 2005) and as a result constant loading could allow for accumulation of these

flavonoids to maximise the anti-oxidant and anti-inflammatory effects (Nieman, 2010; Bell et

al, 2014a). Therefore, cherries may offer a valuable role in the recovery process from

exercise induced muscle damage, by supressing both primary and secondary inflammation

responses to the initial muscle damage caused by mechanical and metabolic stress

(Howatson et al. 2010; Bowtell et al. 2011).

The development from Jacobs et al. (2003) initial study which demonstrated a decrease in

uric acid, plasma C-reactive proteins (CRP) and nitric oxide (NO) has been slow. Currently

only three studies exist on the consumption of cherries on inflammatory indices. Howatson et

al. (2010), found significantly reduced serum interleukin 6 (IL-6), CRP and uric acid in the

tart cherry supplement group when compared to the placebo group following marathon

running. However, the study also identified individuals in the placebo group started with a

greater uric acid content suggesting the participants in the placebo group may have been

more prone to inflammation initially. However, both IL-6 and CRP were reduced in the tart

cherry group when compared to placebo during the study. In addition, Bowtell et al. (2011),

identified that highly sensitive C-reactive proteins tended to be lower in the cherry

supplement group when compared to the placebo fruit cordial group. Although, the

resistance knee extension training Bowtell et al. (2010) adopted, failed to significantly

increase the response of highly sensitive C-reactive proteins. More recently Bell et al.

(2014b) identified both IL-6 and hsCRP were reduced following cherry supplementation

when compared to a placebo after repeated cycle sprint trials. This reduction in inflammatory

markers post exercise when compared to the placebo group, in combination with the greater

increase between trials 2 and 3 in the placebo group formed the conclusion that cherries

play a role in blunting a secondary inflammation response from the initial muscle damage.

However, in blunting the inflammatory process it has been argued physiological adaptation

may be hampered. Schoenfeld (2012) emphasised the need for inflammation for long-term

hypertrophy adaptations. Its suggested inflammation is needed to increase swelling which

accumulates fluid and plasma protein in the localised tissue which results in greater protein

synthesis, therefore, when cell swelling is reduced optimal protein synthesis is inhibited

(Schoenfeld 2012). Currently no research exists to indicate tart cherry supplementation

inhibits physiological adaptations (Bell et al. 2014a) and the need to study its effects on

possible blunting of physiological adaptations is needed. Research on NSAIDs which inhibit

COX-2, like tart cherries (Seeram et al. 2001) have reduced the satellite cell response



(Bamman, 2007) which are responsible for muscle growth as individuals with higher satellite

cell pools saw greater muscle growth following exercise (Parise, 2014). To conclude, if we

adopt a loading strategy similar to either Howatson et al. (2010) or Bell et al. (2014b), we

should also expect an anti-inflammatory response following exercise inducing muscle

damage; however, in doing so muscular hypertrophy may be hindered.

2.9. Oxidative stress

Bell et al. (2014b) suggest that the primary and secondary anti-inflammatory responses

following tart cherry consumption was due to the reduced oxidative stress tissue damage. In

contrast, Mastaloudis et al. (2004) concluded a supplementation period of 6 weeks using

vitamin E and C failed to attenuate inflammation in ultramarathon runners. Therefore, it

suggests either tart cherries may offer greater antioxidant benefits than vitamin E and C or

the metabolic cost of the sprint exercises was far lower than ultra-marathon running which

meant there was significantly less reactive oxygen species (ROS) due to the lower oxygen

consumption in sprints, compared to an ultra-marathon. It is widely acknowledged that

exercise increases the proportion of ROS which often results in the scavenging of electrons

from muscle tissue causing muscle damage (Kruk, 2011). Therefore, it is proposed

increasing the number of antioxidants ingested would overcome this muscle damage by

neutralising radicals, which may therefore, be why tart cherries offer a viable method of

reducing muscle damage and speeding up the recovery process (Bell et al. 2014a).

However, research has indicated the blunting of muscle damage by reducing oxidative

stress as much as possible can have negative effects on physiological adaptation. Peternelj

and Coombes (2011) reported antioxidant intake greater than usual dietary consumption can

interfere with physiological processes related to ROS such as insulin signalling and

vasodilation. In the case of cherry supplementation no current study exists which has studied

or demonstrated impaired physiological adaptation following a period of cherry

supplementation (Bell et al. 2014a).

Currently only 3 human studies exist on the effects of tart cherry supplementation on

oxidative stress. Howatson et al. (2010) was the initial human study which found attenuated

oxidative stress following cherry supplementation 5 days prior to a marathon, on the day of

the marathon and 2 days post marathon. The study identified a significant increase in

thiobarbituric acid reactive species (TBARS) 48 hours post marathon in the placebo group



whereas the cherry group did not significantly increase. In contrast, Bowtell et al. (2011)

adopted an exercise which induced muscle damage primarily through the mechanical stress

model, but still identified Protein carbonyls (PC) were significantly reduced throughout the

protocol in the tart cherry condition. Therefore, it’s suggested tart cherries successfully

reduce oxidative stress following both exercise high in metabolic and mechanical stress. Bell

et al (2014b) reinforces this conclusion, as a significant decrease in lipid hydroperoxides was

seen throughout the trial in the cherry group when compared to placebo following a 7 day

supplementation period following sprint cycle exercises. However the role in which

anthocyanins play is not clear. Studies have found poor bioavailability of anthocyanins in

food choices such as red wine and grape juice (Bitsch et al. 2004) which are typically high in

antioxidants (Seeram et al. 2008). Fang (2014), identified diets high in milk, carbohydrates

and other flavonoids tended to prevent absorption; whilst anthocyanins could be excreted

from the system in the form of bile or urine without being metabolized. This suggests the

anthocyanins content of tart cherries may not directly reduce oxidative damage but indirectly

cause a greater antioxidant defence to reactive oxygen species due to the aforementioned

studies finding reductions in markers of oxidative stress. From the literature we can conclude

cherry supplements may be more beneficial in reducing oxidative stress in exercise which

has a high metabolic content. However, more research needs to be done on the effects of

tart cherry supplementation and the possible negative impacts on physiological adaptation.

Finally, more research needs to be done on the effects of oxidative stress following

mechanical muscle damage as Bell et al (2014b) suggested PC used to measure oxidative

stress by Bowtell et al. (2011) was a poor marker of oxidative stress.

2.10. Perceived muscle soreness

As a result of the anti-inflammatory and antioxidant content of the tart cherry juice, it would

be expected that pain would significantly be reduced, if the muscle fibres were less damaged

and still able to perform near normal forceful contraction. However, the literature on the

effectiveness of tart cherry on subjected ratings of perceived pain/soreness are conflicted.

Attenuated pain ratings were initially reported by Connolly et al. (2006) following a bout of

maximal contractions of the elbow flexor. Connolly et al (2006) identified pain was scored 0.8

higher in the placebo group than the cherry group when measured on a 1-10 scale, with pain

also peaking at 24 hours in the cherry group whilst taking 48 hours in the placebo group.

Similarly, Bowtell et al. (2011) adopted a similar DOMS inducing exercise; (maximal knee

extension exercises) and found that cherry juice was beneficial in reducing pain following

pressure pain threshold testing. However, results failed to reach significance but a clear

trend of reduced pain was seen in the cherry group.



In contrast, to the aforementioned studies which induced DOMS primarily through the

mechanical stress methods, Howatson et al. (2010) induced DOMS through marathon

running provoking both mechanical and metabolic stress processes. Howatson et al. (2010)

identified trends of higher perceived soreness ratings measured using a VAS questionnaire

24 and 48 hours after the marathon whilst both the cherry and placebo group were rated

equal in perceived soreness after the marathon. This result is surprising when Howatson et

al. (2010) also recorded reduced CK and increased MVC in the cherry group than placebo.

This may indicate pain is an unsuitable marker for measures of physiological recovery.

However, pain should not be ignored and efforts should be made to reduce pain especially

amongst untrained individuals as indeed, pain is commonly associated with a negative

emotional response which can often result in avoidance behaviour (Letham et al.1983) and

drop outs of exercise programs (Dalle-Grave et al. 2010). Furthermore, Howatson et al.

(2010) may have caused significantly more muscle damage by exhausting the muscle fibres

metabolically and mechanically, as a result too much muscle damage may have occurred for

any supplement to be of benefit in reducing the perception of pain.

Kuehl et al. (2010) studied the effects of cherry supplementation on muscle pain following

endurance running (26.3 km). The study identified a 50.1% reduction in perceived muscle

soreness post-race when measured on a VAS questionnaire, but failed to follow up with

measures 24 and 48 hour post-race. As a result, we cannot identify if tart cherry

supplementation attenuates pain days after the race or made pain peak earlier in the

aforementioned study, which has been demonstrated in DOMS inducing exercises high in

mechanical stress (Connolly et al. 2006; Bowtell et al. 2011). To conclude, the literature

suggests cherry supplementation has proven effective in reducing perceived pain in well

trained subjects following exercise high in mechanical stress (Bowtell et al. 2011), whilst

exercise high in both mechanical and metabolic stress have yielded conflicted results,

identifying the need for future research in the area in terms of greater studies inducing

muscle damage through metabolic stress, and more studies on mechanical muscle damage

in untrained subjects.

2.11. Dosage strategy

Currently no dose-response study in terms of; dosage or loading strategy of cherries exist

and whilst the studies which exist have found positive outcomes, the reasoning behind the

dosage utilized is not fully understood (Bell et al. 2014a). Jacobs et al. (2003) initial study

indicated that 45 cherries per day was beneficial in reducing inflammatory markers.

However, more recent studied increased the dosage by double the amount with a loading

period. Connolly et al. (2006) adopted a dosage strategy of 100-120 cherries per day, 4 days



before the exercise, on the day and 3 days after. This dosage strategy saw beneficial results

in terms of force regeneration and reduced perception of pain. Kuehl et al. (2010), adopted a

7 day loading strategy of 90-100 cherries per day, before the race, which resulted in positive

effects on perceived muscle soreness post-race. However, the study’s failed to measure

markers of inflammation and oxidative stress and therefore, we cannot see how the dose

adopted directly affected markers of inflammation and oxidative stress and can only infer the

anthocyanins and flavonoids were successful in aiding recovery. Howatson et al. (2010)

adopted a loading period 5 days before the marathon, on the day and 2 days after,

consuming approximately 100-120 cherries per day. This method saw the greatest effects in

reducing inflammation and oxidative stress as IL-6 and CRP were significantly reduced in

the cherry group when compared to the placebo group throughout the trial. Therefore, a

loading strategy, 5 days before, on the day and 2 days prior consuming approximately 100-

120 cherries may be successful in reducing inflammation and oxidative stress due to

sufficient phytochemicals being absorbed, aiding the recovery process in terms of; muscle

damage, force regeneration and pain. However, no study has followed another’s dosage

strategy therefore, it may be beneficial in the future to replicate the dosage used in previous

studies, in order to see if it yields the same results. Currently it is unknown how lower or

higher doses of cherries will affect the recovery process, but adopting a similar dosage

strategy to Howatson et al. (2010) may produce beneficial results in speeding up the

recovery process. Interestingly Kuehl et al. (2010) adopted to consume 20-30 cherries less

than Howatson et al. (2010) and identified attenuated pain whereas Howatson et al. (2010)

found the placebo had lower perceived soreness ratings. Therefore, the need for research

around an optimal and cost effective dose of cherries per day is needed, especially when

attempting to make it a viable option for untrained individuals who are looking to become

active and avoid the feeling of pain which is accompanied with unaccustomed or vigorous

exercise.

2.12. Participants

No study which currently exists to our knowledge focuses on specifically untrained subjects.

Two studies focused specifically on recreational level marathon runners (Howatson et al.

2010) and distance runners (Kuehl et al. 2010), whilst two studies focused on well-trained

participants (Bowtell et al. 2011; Bell et al. 2014b). A few studies opted for a full male sample

(Connolly et al. 2006; Bowtell et al. 2011; Bell et al. 2014b) in case of any specific gender

effects on muscle damage and recovery. However, Dannecker et al (2003) showed females

only reported more pain to experimental stimuli such as electro-neuromuscular stimulation.

Furthermore, Rinard et al. (2000) studied a larger sample of males and females and found



no significant difference in soreness ratings using similar eccentric exercise protocols. The

repeated bout effect is a phenomena well known which produces a protective effect against

muscle damage (Xin et al. 2014) and as a result any positive results seen in the previous

studies may have been due to the participants already having some form of protection from

muscle damage and its debilitative symptoms. Therefore, future research needs to be

conducted on untrained participants in order to see if tart cherry supplementation still has

beneficial effects on individuals who have no physiological adaptation to muscle damage.

Furthermore, it is also important to focus on reducing the time to recover and more

importantly the pain response to muscle damage in the untrained population in order to

overcome this potential barrier to exercise. Letham et al. (1983) suggested pain is often

accompanied by a negative emotional response leading to avoidance behaviour. Dalle-

Grave et al. (2010) reinforce this view finding pain was a common barrier to obese

individuals exercising, whilst more recently Van Schijndel-Speet (2014) identified pain and

physical discomfort were barriers to exercise in elder individuals. Hopefully by blunting the

pain response, individuals will not display avoidance behaviour and may decide to adopt an

active lifestyle; to overcome the pandemic proportion of physical inactivity which is currently

the fourth leading cause of death worldwide (Kohl et al. 2012).

2.13. Hypothesis

From reviewing the literature we hypothesis that tart cherry supplementation for a period of 8

days (5 days prior, on the day and 2 days post) will have a positive impact on recovery from

exercise induced muscle damage, due to the anti-inflammatory nature and antioxidant

content of the phytochemicals in cherries. By adopting this loading strategy proven to absorb

sufficient phytochemicals to reduced inflammation and oxidative stress (Howatson et al.

2010) we expect to see a number of benefits when using tart cherry supplementation in an

untrained population following eccentric contractions on an isokinetic dynamometer. The

benefits we expect to occur in our untrained participants throughout the study are as follows.

1) We expect to see significantly improved muscle force regeneration in the tart cherry group

when compared to placebo, with values of force being closer to baseline values 48 hours

post DOMS exercise, which has been demonstrated in previous studies.

2) We do not expect to see any significant differences between groups, on markers of CK,

48 hours post exercise due to it being a poorer marker of muscle damage, whilst research

has shown both raised and reduced CK following tart cherry supplementation when

compared to a placebo group.



3) Finally, we expect to see a reduction in perceived muscle soreness following the ingestion

of tart cherry juice. We expect pain to be lower in the tart cherry group when compared to

placebo for 24, 48 and 72 hours post DOMS exercise.

3. Methods

3.1. Participants

Six untrained participants, (male n = 5, female n = 1, age = 20.5 ± 2.3 yr, weight = 81.6 ±

21.8 kg, height = 175.9 ± 8.7 cm) completed the study. Untrained participants were defined

as individuals who had not participated in competitive sporting events within the past 3

months and who were not currently training for competition. Participants were recruited via a

questionnaire to ensure participants fell within our untrained category. The study was

approved by Sheffield Hallam University. All participants were made aware of the

experimental protocol via a written participant information sheet (see Appendix 2) which

included the procedure, potential risks, benefits and rights as a participant. A medical health

questionnaire (see Appendix 3) was completed to assess whether participants could

participate in the study. Signed consent forms were obtained (see Appendix 4). Exclusion

criteria for the study included; those currently competing in sport or training for a sporting

event, individuals with known allergies to cherry juice, individuals with known co-morbidities

and individuals injured or prone to injury in the lower limbs.

3.2. Experimental design.

The experiment adopted a randomised, counter-balanced cross over design where

participants completed two main trials which were separated by a 6 day wash out period.

Participants consumed either Cherry active juice concentration (CA) or a commercially

available cherry cordial (CC) for 8 days in each trial. In each trial, participants completed a

DOMS inducing exercise protocol on day 6 of the supplementation period (5 sets of 12

maximal effort eccentric hamstring exercises on an isokinetic dynamometer). Measures of

CK were taken before the DOMS exercise and 48 hours after the exercise. MVC was Faculty of Health and Wellbeing Sheffield Hallam University

Page 17


measured using eccentric peak torque before the DOMS exercise, after the DOMS exercise

and 48 hours after the DOMS exercise, whilst VAS questionnaires were completed pre, post

and up to 72 hours after the DOMS inducing exercise to measures perceived muscle

soreness. Participants returned to the lab at the same time in a fasted state to standardise

each testing condition. Participants were instructed to keep records of diet and physical

activity from the start of supplement consumption, up until 48 hours after the DOMS exercise

and asked to replicate during the second trial.

3.3. Nutritional supplements.

A 15 ml serving of Cherry Active Concentrate Juice is equivalent to 40-50 cherries per drink.

Therefore, participants in the cherry active group consumed 90-100 cherries per day by

consuming two 15 ml serving per day. The Cherry Active juice used was the same

supplement used in Bowtell et al. (2011) study. Therefore, each 15ml of Cherry Active juice

combined with half a pint of water contained approximately 4.558 mgImL of anthocyanins

with an oxygen radical absorbance capacity (ORAC) of 137.5 mmolIL. The cherry cordial

placebo was adopted to have similar taste and appearance but without the phytochemical

properties of the tart cherry group. Both CA and CC supplements were consumed for a total

of 8 days, consuming two 15 ml supplements per days. The nutritional information of each

supplement can be found in table 1. Participants were asked to consume one drink in the

morning and another before they went to bed.

Table 1. Nutritional content of each nutritional supplement.

Cherry Active

(Per 30 ml)

Cherry Cordial Placebo

(per 30ml)

Energy 102 Kcal 30 Kcal

Protein 1.1g 0g

Carbohydrate 24.5g 7.7g

Fat 0g 0g

Fibre 2.6g 0g

Salt 0g 0g

Anthocyanin 9.117 mgIML Trace

ORAC 275 mmolIL Trace

3.4. Experimental protocol (Figure 1).

Participants arrived at the lab in a fasted state on the 6 th day of supplementation and were

seated. Participants were given a Visual Analog Scale (VAS) questionnaire (see Appendix 5)



to complete to account for a measure of perceived soreness before any capillary blood

sample, power testing or DOMS inducing exercise was complete. Once participants

completed the VAS questionnaire a capillary blood sample was taken following the WHO

guidelines (WHO, 2010) and analysed via a Photometer (Reflotron, Boehringer Mannheim

GMBH, Germany) to give a baseline measure of CK. After the baseline blood analysis, a

baseline MVC measure was taken using an isokinetic dynamometer (Biodex stystem 3). The

procedure used has previously been shown to provide reliable measures of torque (Drouin et

al. 2004). The isokinetic dynamometer was set at an angular torque of 60 degrees.secˉ¹,

with range of motion set from 90 degrees until participants felt their hamstrings tightening.

Participants were then given 3 attempts with a brief 30 second rest between efforts and the

greatest force reading was taken. After a 3 minute rest period the DOMS inducing exercise

was completed.

All participants warmed up for 5 minutes on a cycle ergometer (824E, Monarch AB, Sweden)

with self-selected weight and cadence to achieve 60% Age Predicted Heart rate max

(APHRM) (Polar Electro OY, FS1, Finland). Following the warm up participants were

introduced to the isokinetic dynamometer to carry out the eccentric hamstring exercise on

the right leg. Isokinetic dynamometer was set at an angular peak torque of 60 degrees.secˉ¹.

The exercise was performed maximally over a period of 5 sets consisting of 12 reps each set

with a one minute rest period between sets. The range of motion was set at; 90 degrees

towards limit whilst the away limit was set at a point in which the participant noted tightening

in the hamstring muscle group.

Immediately after the DOMS inducing exercise another VAS questionnaire was completed

and 3 minutes after the exercise another MVC was completed on the isokinetic

dynamometer. Again the participants were allowed 3 attempts with a brief 30 second rest

period between efforts and the highest force reading was taken.

Participants then returned to the lab at the same time in a fasted state, 48 hours after the

DOMS inducing exercise to have post measurements completed. Participants arrived with a

completed VAS questionnaire for 24 and 48 hours after the exercise, which were both

completed in the morning. A capillary blood sample was taken again to see the level of CK

48 hours post exercise and again another 3 MVC were completed following the same

protocol. A final VAS questionnaire was completed 72 hours after the DOMS inducing

exercise.

After a 6 day wash out period the second trial began. The experimental protocol stayed

exactly the same, targeting the right leg due to a repeated contralateral bout effect existing

(Xin et al. 2014) and to prevent results being effected by leg dominance effects. Faculty of Health and Wellbeing Sheffield Hallam University

Page 19


3.5. VAS questionnaire.

A VAS questionnaire (0-100 mm) (see Appendix 5) was completed for the; quadricep,

hamstring, tibialis anterior and calf muscle groups, where 0mm was ‘no pain’ to 100mm

‘severe pain’. The VAS was given before DOMS test, after the DOMS test, 24-72 hours after

the test to assess perceived ratings of muscle soreness. The VAS questionnaire was

completed in the morning after waking up to standardise the measure of perceived soreness

for all days excluding the DOMS inducing exercise day. The VAS scale was used due to its

validity and reliability in measuring acute pain (Bijur et al. 2003) and the ratio level data it

produces making it a more favourable method than Likert scales (Williamson and Hoggart,

2005).

3.6. Serum CK blood analysis.

CK was measured through obtaining a capillary blood sample from participant’s finger tips

on their desirable finger. The blood samples were collected from participants following an

overnight fast. Approximately 20 µl of blood was collected, which was then analysed using a

Photometer (Reflotron, Boehringer Mannheim GMBH, Germany), before the test and 48

hours after the test to assess markers of muscle damage following the DOMS inducing

exercise. Serum CK was measured before the MVC to get a baseline value of serum CK

before the experimental protocol was conducted.

3.7. Isokinetic dynamometer.

The isokinetic dynamometer (System 3 pro, Biodex medical systems inc. USA) was set at an

angular velocity of 60 degrees.secˉ¹ for both the MVC and DOMS inducing exercise and

always performed on the right leg throughout the study. The ranges of motion were set at:

90 towards limit, whilst the away limit was set when participants noted a tightening of the⁰

hamstring group. The MVC consisted of 3 reps, with a 30 second rest in between efforts,

whilst the DOMS inducing exercise consisted of 5 sets of 12 reps with a 1 minute rest period

between sets. Both protocols were completed with maximal effort and participants were

given verbal encouragement to perform maximally. The DOMS inducing exercise was

performed once per trial on the 6th day of supplementation. MVC was performed 3 times per

trial; before, after and 48 hours after the DOMS inducing exercise. Eccentric peak torque

was collected during the MVC to account for changes in muscular force production from

baseline following eccentric hamstring exercise.


Day 1 – 5 Day 6

5 sets of 12 reps at maximal effortMVC MVC

Day 7 Day 8

MVC

VAS VAS CK

VAS VAS

Day 9

Tart Cherry or Placebo supplementation Day 1 - 8

VAS CK


3.8. Data Collection/analysis.

Data was collected from baseline, after testing, 1-3 days post DOMS inducing exercise. The

greatest MVC value over each 3 attempts was used as the participants maximum force

exerted. MVC, CK and VAS were reported as mean values with standard deviations

following statistical analysis. Statistical analysis was performed using SPSS statistics for

Windows, Version 22.0. Normality of the data was assessed using the Sharpiro-Wilk test,

before conducting a two way repeated measures ANOVA, treatment (tart cherry vs placebo)

by time (Before, after, 24 48, 72 hours post DOMS exercise) to identify any statistical

significance of treatment or time on the studies dependent variables (CK, MVC and VAS of

perceived muscle soreness). Testing for homogeneity of variance was done using a Mauchly

sphericity test. Greenhouse-Geisser adjustment was used for violations of the assumptions

of sphericity. The accepted alpha level of the study was set at 0.05 to test for statistical

significance. Cohen’s d was used to calculate effect size for visual trends.

Figure 1. Schematic diagram of the experimental protocol. For the second trial this

procedure was replicated following a 6 day wash out period, with participants swapping

supplement groups. Experimental testing took place between 12:00 – 4:00 PM. (CK;

Creatine Kinase, MVC; Maximum voluntary contraction, VAS; Visual Analog Scale

Questionnaire).



4. Results

4.1. Delayed onset muscle soreness.

Table 2. Perceived muscle soreness descriptive statistics, measured using a Visual Analog

Scale (VAS) questionnaire over 5 time points.

Pre-Exercise Post-Exercise 24 h 48 h 72 h

Hamstrings

DOMS*** (mm)

Tart

Cherry 6 ± 8 25 ± 26 35 ± 22 27 ± 22 17 ± 22

Placebo 5 ± 6 49 ± 21 56 ± 29 65 ± 22 45 ± 23

Quadriceps DOMS

(mm)

Tart

Cherry 6 ± 9 15 ± 22 13 ± 20 6 ± 8 1 ± 1

Placebo 5 ± 6 22 ± 19 15 ± 22 13 ± 25 11 ± 26

Calf DOMS (mm)

Tart

Cherry 5 ± 12 24 ± 27 18 ± 25 7 ± 9 1 ± 1

Placebo 20 ± 27 24 ± 20 7 ± 13 7 ± 13 4 ± 10

Tibialis Anterior

(mm)



Tart

Cherry 2 ± 4 15 ± 22 14 ± 25 2 ± 2 1 ± 1

Placebo 12 ± 19 13 ± 14 10 ± 15 12 ± 15 6 ± 14

Data is presented as mean ± standard deviation.

There was a main effect of time for Hamstrings DOMS (P = < 0.01)*.

The increase in Hamstrings DOMS tended to be reduced in the Tart Cherry group (condition

main effect, P = 0.045)*, with a significant time and condition interaction (Time*Condition

interaction effect, P = 0.006)*.

DOMS; delayed onset muscle soreness.

There was only significant increases in perceived muscle soreness in the Hamstrings muscle

group. Table 2, identifies that all muscle groups excluding hamstrings peaked pre-exercise

and began to return to baseline levels. Figure 2 identifies muscle soreness in the hamstring

group peaked at 24 hours in the tart cherry group whereas, soreness peaked at 48 hours in

the placebo. The large standard deviations indicate variability in perceived soreness ratings

between participants. There was a main effect of time (F (4, 20) = 16.993, P = < 0.01),

demonstrating the experimental protocol induced delayed onset muscle soreness in the

targeted hamstring muscle group, from pre-exercise values up until 72 hours post-exercise.

There was also a condition effect which identified pain reduction in the hamstring during the

tart cherry condition (F (1, 5) = 7.079, P = 0.045). Furthermore, there was an increase in

perceived muscle soreness of the hamstring post-exercise – 72 hours post in the placebo

condition when compared to the tart cherry condition (interaction effect, F (4, 20) = 5.065, P

= 0.006).

Pre-ex Post-ex 24 h 48 h 72 h0

200

400

600

800

1000

1200

1400

1600

1800

Percieved muscle soreness in the Hamstring muscle group

Tart cherry Placebo

VAS

(% o

f pre

-ex

VAS)



Figure 2. VAS perceived soreness values represented as change from pre-DOMS inducing

exercise values. There was a significant main effect of time (P = < 0.01) and condition (P =

0.045) along with a significant time*condition interaction effect (P = 0.006). All data points

had a significant time effect from pre-exercise values.

4.2. Maximum Voluntary Contraction (MVC)

Table 3. Maximum Voluntary Contraction (MVC) indirect marker of muscle recovery,

descriptive statistics.

Pre-Exercise Post-Exercise 48 h

MVC (N.mˉ¹)*

Tart Cherry 158.9 ± 67.6 130.1 ± 40.8 138.1 ± 48.5

Placebo 151.9 ± 45.6 123.6 ± 31.2 121.6 ± 47.4

Data is presented as mean ± standard deviation.

There was a main effects of time for MVC (P = 0.038)*

MVC; Maximum Voluntary Contraction

MVC of the hamstring muscle group was reduced on average to 84% of values pre-DOMS

inducing exercise and were still reduced to 85% 48 hours post-DOMS inducing exercise.

There was a significant main effect of time (F (2, 10) = 4,629, P = 0.038), this significant

difference occurred between pre and 48 hours post-exercise (P = 0.021). There was no

significant difference in MVC between conditions (main effect of condition, F (1, 5) = 1.998,

P = 0.217) and there was no significant difference in force recovery over time between

condition (interaction effect, F (1.017, 5.086) = 0.193, P = 0.683). However, trends identified

muscular force recovery tended to be increased in the tart cherry group with levels returning

to 91% ± 12% compared to 80% ± 13% in the placebo group 48 hours post-DOMS inducing

exercise (figure 3). Cohen’s effect size value (d=0.38) indicated a small positive effect of tart

cherry juice on muscle force recovery when compared to placebo. Cohen’s effect size (d =

0.39) indicated there was a small difference in force from pre-exercise to 48h post-exercise

in the tart cherry group when compared to a larger effect (d = 0.71) in the placebo identifying

greater reductions in force.



BL after 48 hours0

20

40

60

80

100

120

Maximum Voluntary Contraction (MVC)

Tart CherryPlacebo

MVC

(% o

f pre

-ex

MVC

)

Figure 3. MVC values represented as change from pre-DOMS inducing exercise values.

There was no significant main effect of condition (P = 0.217), or time*condition interaction

effect (P = 0.683). However, the graph displays force recovery tended to be improved in the

tart cherry condition 48h post exercise.

4.3. Creatine Kinase

Table 4. Serum Creatine Kinase marker of muscle damage, descriptive statistics.

Pre-Exercise 48 h

CK (µ/l, n = 5)

Tart Cherry 130 ± 115. 9 101 ± 67. 5

Placebo 55.3 ± 35.8 188.6 ± 177. 4

Data reported as mean and standard deviation.

CK: Creatine Kinase.

CK data was based on 5 participants; 1 participant failed to complete blood analysis

throughout the study. The descriptive statistics identify CK was reduced by 22% 48 hours

post-DOMS inducing exercise in the tart cherry group whilst the placebo group increased by

around 240% compared to pre-exercise values. There was no significant increase in serum

CK 48 hours post-DOMS inducing exercise (main effect of time, F (1, 4) = 2.221, P = 0.210).

The differences between tart cherry and placebo conditions were also insignificant (main

effect of condition, F (1, 4) = 0.020, P = 0.894). Changes in CK from pre-exercise values

were not statistically significant between tart cherry and placebo condition (Interaction effect,



F (1, 4) = 2.217, P = 0.211). However, a clear trend that CK activity was greater in the

placebo condition is observed as the tart cherry groups serum CK was reduced to 78% of

the baseline value whereas, the placebo group had increased to 340% of the baseline value

(Figure 4). Cohen’s effect size value (d = 0.97) suggests there was a larger baseline value of

CK in the tart cherry group, whilst 48 hours post-exercise effect size values (d = -0.73)

indicates there was moderate significance in the tart cherry group to reduce CK when

compared to placebo. Furthermore, Cohen’s effect size value (d = 0.34) suggests there was

a small positive effect of tart cherries on CK reduction, 48 hours post-exercise when

compared to a large negative effect (d = -1.16) seen 48 hours post-exercise in the placebo

group to reduce CK.

BL 48 hours0

50

100

150

200

250

300

350

400

Creatine Kinase (CK)

Tart CherryPlacebo

CK (%

of p

re-e

x va

lues

)

Figure 4. CK values represented as change from pre-DOMS inducing exercise values. There

was no significant main effect of condition (P = 0.894), or time*condition interaction effect (P

= 0.211). However, the graph displays trends that CK was greater in the placebo group

when compared to tart cherry group which was reduced from pre-exercise values.

5. Discussion

The main finding of this study was the reduction in perceived muscle soreness of the

hamstring group following maximal eccentric hamstring contractions when consuming tart

cherry juice 5 days pre, on the day, and 2 days post eccentric exercise. This improvement in

perceived muscle soreness was combined with trends of increased muscle force

regeneration and decreases CK in the tart cherry group 48 hours post-eccentric exercise

when compared to the placebo group. However, no significant increases in CK and

decreases in MVC post-exercise question the amount of muscle damage induced by the



eccentric exercise protocol. Furthermore, there was no significant reduction in perceived

soreness of either; quadriceps, calf or tibialis anterior muscle groups between tart cherry and

placebo trials. This may be due to the relatively low ratings of soreness in the

aforementioned muscle groups.

5.1 Functional recovery

The findings of this study in terms of trends of greater muscle force regeneration in the tart

cherry group is also demonstrated in previous literature as, Connolly et al. (2006), Howatson

et al. (2010) and Bowtell et al. (2011) all identified muscle force returned closer to baseline

values 48 hours post-eccentric exercise and marathon running. This study identifies muscle

force returned closer to baseline values during the tart cherry condition 48 hours post

exercise, whilst the force in the placebo group continued to decrease from baseline values.

This study produced similar decreases in strength post activity (~84% of pre-ex values)

between both tart cherry and placebo groups which was also found by Howatson et al.

(2010) and Bowtell et al. (2011) following marathon running and knee extension exercises,

with greater increases in muscular strength 48 hours post-exercise in the tart cherry group.

This led to the belief that tart cherries do not work by preventing the structural damage of

muscle tissue following bouts of eccentric or strenuous exercise but instead reduces the

local inflammatory response following the onset of muscle damage (Howatson et al. 2010,

Bowtell et al. 2011). Unfortunately this study failed to measure markers of inflammation.

However, Howatson et al. (2010) identified IL-6 markers of inflammation were closely

correlated with serum CK. Therefore, from this association we may be able to use serum CK

as an indirect marker of muscle damage and inflammation.

This study demonstrated serum CK markers of muscle damage were reduced by 22% from

baseline values, 48 hours post-eccentric exercise when consuming tart cherries, compared

to a 240% increase in the placebo group. This was accompanied with a marked increase

(80%) in baseline CK values in the tart cherry group, indicating participants may have failed

to standardise their activity between trials. Therefore, if IL-6 is closely associated with CK as

Howatson et al. (2010) identified it would suggest either; tart cherries successfully worked at

blunting a secondary inflammation response by inhibiting inflammatory enzymes (COX), or

the experimental protocol failed to induce muscle damage and as a result no subsequent

local inflammation occurred. Unfortunately this study only utilised one follow-up serum CK

blood sample after 48 hours to identify change from baseline. Therefore, we cannot identify

whether the experimental protocol did in fact, cause muscle damage. Though the study

demonstrated both tart cherry and placebo groups muscular force after 48 hours was still

decreased from baseline. The tart cherry group reached 91% of baseline MVC values



whereas placebo only achieved 80% or pre-exercise MVC values, which may best indicate

muscle recovery (Xin et al. 2014) due to CK having a large variability because of high and

low responders (Tajra et al. 2014) which is evident in the present study due to the large

standard deviation in the placebo group 48 hours post exercise.

Kasapis and Thompson (2005) systematic review identified muscle damage did not have to

occur for a marked increase in inflammatory marker IL-6. The increases in IL-6 were greater

but shorter in duration in the absence of muscle damage. Furthermore, Clarkson et al.

(1992) proposed the idea that range of motion was inhibited post exercise bout when CK

was still significantly decreased due to the accumulation of calcium. This theory has been

reinforced by the findings of Butterfield (2010) who identified calcium caused an

inflammatory response even when no structural muscle damage occurred. This could

explain the studies positive findings in terms of greater trends towards improved muscle

force recovery in the tart cherry group when compared to placebo. Like Howatson et al.

(2010) and Bowtell et al. (2011), tart cherry supplementation may have supressed the

inflammatory response to either; muscle damage, or the inflammatory response associated

with muscular contractions (Kasapis and Thompson, 2005). In agreement with Howatson et

al. (2010) this study identifies trends of reduced CK in the tart cherry group when compared

to placebo. However, both Howatson et al. (2010) and Bowtell et al. (2011) identified

increased CK 48 hours post-exercise when compared to baseline values, whilst this study

identified a reduction in CK 48 hours post-exercise in the tart cherry group. The difference in

results from this study compared to previous studies may be due to the experimental

protocol and participants used. Howatson et al. (2010) adopted to induce muscle damage

through marathon running whilst Bowtell et al. (2011) adopted knee extension exercises,

similar to the present protocol. It is possible the present findings showed no significant

increase in CK due to participants being untrained compared to Bowtell et al. (2011) well

trained participants. Well trained participants can work at higher capacity over a prolonged

period of time due to the strength adaptations from training, whilst untrained participants

fatigue and are unable to produce forceful muscular contractions for a prolonged duration

(Shimano et al. 2006). Furthermore, Friden and Lieber (2000) suggest, humans work at

submaximal intensities rather than maximally during eccentric contractions due to the feeling

of pain. Although participants were asked and verbally encouraged to perform maximally, it’s

highly unlikely they were capable of doing so, due to the perception of pain. This perception

of pain may have been of greater magnitude in this study compared to Bowtell et al. (2011)

due to participants having limited adaptation to eccentric lengthening contractions. If

participants are not working maximally there would be less stress in the muscle fibre limiting

muscle damage caused from the DOMS-inducing exercise (Armstrong et al. 1991, Tee et al.



2007). In addition, the study failed to measure total work, which may have provided an

explanation to why CK decreased in the tart cherry condition. Participants may have

produced more total work in the placebo condition when compared to tart cherry which

would explain why CK was reduced by 22% 48 hours post-eccentric exercise whilst the

placebo saw a 240% increase from baseline.

Unlike, Howatson et al. (2010), Bowtell et al. (2011) and Bell (2014b) this study failed to

measure markers of oxidative stress. Whilst oxidative stress is predominantly observed in

aerobic activity, its effects on resistance exercise is conflicted (Bowtell et al. 2011). Deminice

et al. (2010) identified oxidative stress was induced following 3 sets of 10 reps at a moderate

intensity, identifying a 45% increase in TBARS which was statistically significant, concluding

resistance exercise can induce oxidative stress. Therefore, our study may have induced

oxidative stress due to the greater numbers of sets and higher intensity than the

aforementioned study. This study adopted a loading strategy utilized by Howatson et al.

(2010) due to positive findings on reduced IL-6, CRP and TBARS. As a result, greater trends

of muscle function recovery in the tart cherry group when compared to the placebo group

may have been identified due to a reduction in oxidative stress from consuming tart cherries.

Howatson et al. (2010), identified TBARS in the tart cherry group were approximately 10

uMol/L less than the placebo group after 48 hours, whilst it was important to note total

antioxidant status (TAS) was sufficient in reducing oxidative stress up until 24 hours in the

placebo group. There was also no increase in TBARS following marathon running when

participants consumed the tart cherry juice. Bowtell et al. (2011) also identified PC markers

of oxidative stress were decreased 24 hours post eccentric exercise suggesting tart cherries

may prevent oxidative stress even in exercise low in metabolic stress. The possible

reduction in oxidative tissue damage may not only explain why muscle function recovery was

greater in the tart cherry group at 48 hours, whilst the placebo groups force continued to

decrease, but may also explain the decreases in serum CK in the present study. If there is

less oxidative stress, then less muscular damage would occur because of the reduction in

ROS scavenging electrons from muscle tissue, and in turn would yield a reduction in CK.

This was demonstrated by Bell et al. (2014b) who found lower CK values after the third

cycling trial when compared with pre-exercise CK values during a cycle trial predominantly

causing metabolic stress. This decrease in CK was attributed to the tart cherries improving

antioxidant defence systems; leading to reduced cell damage and inflammation. Therefore,

supplementing with tart cherries may have prevented fluctuations in TAS and protected

participants from oxidative stress and tissue damage, leading to reduced inflammation;

accelerating muscle force regeneration and reducing serum CK in this studies untrained

participants.



However, whilst the study aimed at recruiting untrained participants, the definition used in

this study was individuals inactive from sporting competition and training for a period of 3

months. Nosaka et al. (2001) suggested adaptive effects from training supress muscle

damage caused by eccentric exercise when performed no more than 6 months apart.

Therefore, problems with the sample selection may have caused a repeated bout effect,

preventing a significant increase in serum CK. Furthermore, it has been identified that even

a single bout of eccentric exercise markedly decreases the levels of CK when performing the

same exercise over a period of 2 weeks due to the rapid motor unit recruitment adaptations

(Clarkson et al. 1992). Therefore, this studies 6 day wash-out period (7 days from the last

MVC) was not sufficient to reduce the repeated bout effect, which may have prevented

significant increases in serum CK. Future research should look to use the contralateral leg,

with larger sample sizes so the study can be counter-balanced for limb dominance effects.

5.2 Perceived muscle soreness

The initial studies into tart cherry juice by Connolly et al. (2006) and Kuehl et al. (2010)

identified those who consumed tart cherry juice for a 3 day period before eccentric elbow

exercises and 4 days after and 7 days before a long distance (26 km) race was successful at

reducing subjective ratings of pain. This present study reinforces the findings of the

aforementioned studies as there was a significant reduction in hamstring soreness following

the consumptions of tart cherry juice 5 days before, on the day and 2 days post eccentric

hamstring exercise when compared to a placebo group, in untrained participants. This

finding was not surprising when accompanied with reduced CK and increased muscle force

regeneration 48 hours post-exercise when compared to the placebo group. Like Kuehl et al.

(2010), this study demonstrates a decrease in subjective ratings of soreness immediately

after exercise in the tart cherry group. The placebo group had a 96% higher muscle

soreness rating than the tart cherry group immediately after exercise. Furthermore, like

Connolly et al. (2006) the present study identified hamstring soreness peaked at 24 hours

post eccentric exercise in the tart cherry group whereas the placebo did not peak until 48

hours post exercise. The large standard deviation in the study indicates the great variability

in either perceived soreness or individual’s interpretation of the visual analog questionnaire,

which in itself is a limitation of the subjective nature of the visual analog scale.

These results in attenuated perceived soreness ratings contrast the findings of both

Howatson et al. (2010) and Bowtell et al. (2011) who identified no significant reduction in

subjective ratings of soreness. Howatson et al. (2010) identified significant reductions in

inflammation, oxidative stress and improvements in force regeneration following marathon

running. Therefore, it’s surprising that no reduction in soreness was accompanied with such



findings and in fact greater values of muscle soreness were seen in the tart cherry group.

Bowtell et al. (2011), utilized a protocol to induce muscle damage mechanically through knee

extension resistance exercise, which was similar to the protocol utilized in the present study.

However unlike this study’s findings, Bowtell et al. (2011) identified no significant differences

in pain pressure threshold. Whilst Bowtell et al. (2011) identified no significant findings, clear

trends of reduced soreness were seen in the tart cherry group 24 and 48 hours after

exercise as values started to return to baseline values whilst the placebo group’s soreness

continued to increase up to 48 hours post-eccentric exercise which was found in the present

study. All studies apart from Howatson et al (2010) have shown reduced soreness to some

extent. However, the marathon running protocol utilized by Howatson et al. (2010) is greater

in duration than the protocol utilized in this study and all previously published studies

(Connolly et al. 2006, Kuehl et al. 2010, Bowtell et al. 2011, Bell et al. 2014b) which induced

considerable metabolic stress causing a greater magnitude of muscle damage (CK),

compared to the present study and Bowtell et al. (2011) knee extensor exercises. Therefore,

from the present findings and the previous research into tart cherries it suggestes cherries

may have a beneficial effect on post-exercise muscle soreness in not only trained individuals

but also those untrained and unaccustomed to eccentric exercise when moderate amounts

of muscle damage are induced. This reduction in pain in the present study was accompanied

with decreased serum CK and increased force regeneration inferring; tart cherries and

specifically the anthocyanin and flavonoid content may have reduced tissue damage from

oxidative stress and subsequently reduced the inflammatory response to muscle damage,

reducing the feeling of soreness.

5.3 Limitations

Whilst the findings of this study demonstrate tart cherries significantly decreased perceived

soreness following eccentric exercise, whilst showing trends of increased force regeneration

and decreased serum CK in untrained participants, we cannot attribute all these finding to

tart cherry supplementation due to several methodological limitations. Firstly, the differences

between the tart cherry supplement and placebo in terms of appearance, odour and taste

may have made it easy for participants to discern the tart cherry group. As a result, this may

have created demand characteristics from the participants to over-estimate their soreness in

the placebo condition, and under-estimate their soreness in the tart cherry condition.

Furthermore, the difference in calorie and macronutrient content (table 1) may have had an

effect when participants were completing the study in a fasted state. Whilst carbohydrate

status before exercise has found to have no effect on DOMS and muscle damage (Close et

al. 2005), protein before exercise is known to increase protein synthesis post-exercise which



may have caused a measurable decrease in muscle damage (Pasiakos et al. 2014). Whilst

the contents of each supplement were not vastly different, future studies should look to

match the energy and macronutrient contents of each supplement. No restrictions were

placed on medication such as NSAIDS which are known anti-inflammatories to work on

DOMS (Schoenfeld, 2012) and other sources of antioxidants, whilst there is no guarantee

individuals adhered to consuming the supplements. As a result, future research needs to

gain greater control on individual’s diets to reduce antioxidant/anti-inflammatory content to

be able to attribute the findings solely to tart cherry juice.

The elevated pre-exercise values of CK in the tart cherry trial indicates participants did not

replicate their activity logs successfully between trials. Therefore, this cofounding variable

may have affected the results and caused the decrease in CK 48 hours post exercise along

with the reduced perception of pain and increased force regeneration, because of a

repeated bout effect (Clarkson et al. 1992, Nosaka et al. 2002). This was likely the case for

one participant who had a CK value of 301µ/l before the initial trial had begun, arguing how

untrained the participants of the study were. This participant’s decrease in CK to 194 µ/l

would likely be caused by the repeated bout rather than tart cherry supplementation as

studies have shown activity, even concentric in nature reduced serum CK (Kim et al. 2010).

Furthermore, this increase in baseline CK may have caused a considerable effect as the

isokinetic dynamometers away range of motion was reset for each trial. Therefore,

participants with higher baseline CK values may have felt their hamstrings tightening quicker

in one trial compared to the other due to the decreases in range of motion typically observed

following muscle damaging activity (Connolly et al. 2006) due to the calcium accumulation

and subsequent discomfort (Clarkson et al. 1992, Butterfield, 2012). As a result, participants

muscle fibres may have been stretched considerably less in one trial compared to another,

which may be why reductions in CK were found in the tart cherry trial due to no muscle

damage being induced because the fibres may not have been stretched beyond optimum

length to cause micro-injury (Morgan and Proske, 2004). Furthermore, failing to measure

total work between trials means participants could have simply completed less work in the

tart cherry group producing less muscle damage. Therefore, future research needs to be

more stringent on methods to standardise participant’s activity from one trial to the other,

whilst using the same range of motion on the isokinetic dynamometer to ensure the muscle

fibres are being stretched to the same extent. Total work should also be noted to identify

whether the same amount of effort was produced in each trial.

Finally, limitations with the sample used, may not only have affected the results as

previously discussed with participants potentially being untrained for as little as 3 months



and being protected from the effects of eccentric exercise due to the repeated bout effect.

But may also make the sample unable to generalise to a wider untrained population. The

increase in baseline CK from one trial to the other and the large baseline difference between

individuals in the study indicates some participants may be currently training or greater

trained to exercise than they believe. As a result, improved sampling methods are needed to

recruit untrained participants. Future research should look to obtain objective measures

through measuring aerobic capacity (Dogra et al. 2013) and 1 repetition max (Shimano et al.

2006) to assess the participants training status, whilst recruiting individuals unaccustomed to

eccentric exercise may not be sufficient as concentric muscle contractions also supress the

CK muscle damage response due to the repeated bout effect (Kim et al. 2010). Future

samples should look to recruit more participants and be made up of more females. In the

present study only one female participant was included, meaning the results cannot be

generalised to untrained females due to the male bias sample, whilst the small sample size

means we can only infer significance and trends as the sample size is too small to prove

significant effects of tart cherries on recovery of muscle function and soreness.

6. Conclusion

In conclusion, the consumption of 2 tart cherry drinks per day (~90-100 cherries), 5 days pre,

on the day and 2 days post-eccentric hamstring exercise, supressed the perception of

soreness in the hamstring muscle group, whilst showing trends of accelerated force and

muscle recovery in untrained participants. We infer these improvements occurred in the tart

cherry condition due to the anti-inflammatory and anti-oxidative stress properties of the

phytochemicals found in tart cherries. Future research should look to measure inflammation

and oxidative-stress along with functional recovery and perceived soreness to identify

whether tart cherries do significantly reduce oxidative stress and inflammation in untrained

participants which could only be inferred in this present study. Future research should also

focus on the consequences of blunting post-exercise muscle damage and inflammation with

tart cherries and its effects on physiological adaptations such as muscular hypertrophy,

whilst a dose response study may be beneficial on eliciting an optimal dose and loading

period for accelerated recovery from unaccustomed or strenuous exercise.

Word Count: 11994 / 12100



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Appendix 1. Progress Record Form





Appendix 2. Participant information sheet

Project titleThe effects of tart cherry supplementation on muscle damage, muscle force regeneration and perceived muscle soreness, in untrained males and females following isokinetic dynamometry.

Please will you take part in a study looking at the effects cherry juice has on; muscle pain and time for muscles to repair following exercise.

Why have I been recruited?Muscle pain is a barrier to exercise for those who lead a physically inactive lifestyle. Therefore, participants have been selected upon the basis that they have not been active in competitive sport in the past 3 months, and are not training for competition. This is so the muscles won’t be as use to exercise than someone who is active for the majority of the week. We can then use the results from this study and more readily apply them to people with similar activity levels and those who aren’t active at all to see whether cherry juice is a supplement which can help reduce muscle pain and recovery time after exercising.

What will I have to do?Pre-test medical questionnaire: You will be asked to complete the health questionnaire to the best of you knowledge prior to the study to assess your health and whether you can participate in the study for your own safety.

Drinks: As a participant of the study you shall be given a small 15 ml drink of two different cherry cordials either Cherry active Juice or Blossom Cottage Morello Cherry Cordial each diluted with half a pint of water, to take twice per day for 8 days in each condition. You shall take two



drinks per day (for 5 days before the exercise, on the day of the exercise, and for 2 days after the exercise). Drinks should be consumed after waking up and before going to bed.

Exercise tests: You shall return to the lab in a fasted state, and come with a completed soreness questionnaire for the morning. You shall be made familiar with the lab and the equipment we are going to be using. It is important you come in shorts and trainers suitable for exercise else you will not be allowed to participate in the study.

Before the isokinetic dynamometry (resistance test) is carried out we will complete a finger prick blood sample to test for Creatine Kinase which shows how damaged a muscle is, this test should last no longer than a couple of minutes to carry out and should only cause mild discomfort. Your strength will also be tested by maximum contraction of your legs muscle groups, by extending and flexing the knee on an isokinetic dynamometer machine that measures the forces produced from these muscle groups. You shall be given 3 attempts with 3 minutes rest within each attempt, assessing your strength should take no longer than 10 minutes.

15 minutes after the strength test you will then be given time to warm up and at the end of the warm up you shall be reintroduced to the isokinetic dynamometer and asked to carry out a series of knee flexion’s and extensions until you are unable to produce 60% of your maximum force.

15 minutes after the exercise test you will again have your strength assessed on the isokinetic dynamometer machine which again should last no more than 10 minutes.

24 hours exercise test:complete another soreness questionnaire after waking up.

48 hours after exercise test: You will return to the lab at the same time as the day of the exercise test in a fasted state, with a completed soreness questionnaire and again your strength will be tested along with you blood.

72 hours after exercise test: complete another soreness questionnaire after waking up.

It is important you save a food diary and physical activity log for the time you were consuming the fruit juice. This should then be replicated when you change fruit juice groups. In total 8 days should be recorded from initial consumption of the juice up until 48 hours after the exercise test. These 8 days should be replicated as well as possible once beginning the second supplement.

6 days rest: After this 6 days rest period, the experiment will be repeated but you will have a different fruit juice to test. The procedure will remain exactly the same and as previously mentioned you should follow the diet and physical activity logs you did during the first fruit juice condition as best as you can.

What happens once the study is complete?Once the study is complete we will have chance to discuss the participation and debrief about what the results mean and what we were expecting to find. You will also be able to decide whether you want the results to be published or not and you can decide to hide your identity through the use of a coding system.



The data collected with your permission will be analysed and compared to previous research, to see whether cherry juice effects muscle soreness or time taken to recover. The data will only be accessible by me and Sheffield Hallam University once the data has been submitted in a scientific report and participants shall be anonymised.

RisksParticipants may have an allergic reaction or undesirable side effects from cherry juice.Participants may have a bad reaction to blood being taken which may result in fainting.The Exercise/Strength test may cause injury or induce considerable muscle pain.The site from where blood was taken may bruise, be tender or get infected.

Risk assessments will be put in place in order to limit the likelihood of these risks and control measures and emergency procedures put in place for participants safety.

BenefitsGet a valid reading of Individuals strength.Get to sample different cherry juices for free.May have beneficial effects on participants sleep due to the effects of cherry juice.Insight into how scientific research is carried out.

Your rights as a participant Participation is voluntary.You can withdraw from the study whenever you like.You have the right to have your results destroyed.You can keep your identity hidden.Statement of confidentiality - any details or results obtained will not be shared with others.

If you have any further questions please feel free to contact me via email, [email protected].


mailto:[email protected]


Appendix 3. Medical Health Questionnaire

Faculty of Health and Wellbeing Research Ethics CommitteeSport and Exercise Research Ethics Review Group

Pre-Test Medical Questionnaire

Name:

Date of Birth: Age: Sex:

Please answer the following questions by putting a circle round the appropriate response or filling in the blank.

1. How would you describe your present level of activity?Sedentary / Moderately active / Active / Highly active

2. How would you describe you present level of fitness?Unfit / Moderately fit / Trained / Highly trained

3. How would you consider your present body weight?Underweight / Ideal / Slightly over / Very overweight

4. Smoking Habits Are you currently a smoker? Yes / NoHow many do you smoke …….. per day



Are you a previous smoker? Yes / NoHow long is it since you stopped? ......... yearsWere you an occasional smoker? Yes / No

......... per dayWere you a regular smoker? Yes / No

......... per day

5. Do you drink alcohol? Yes / NoIf you answered Yes, do you usually have?An occasional drink / a drink every day / more than one drink a day?

6. Have you had to consult your doctor within the last six months? Yes / NoIf you answered Yes, please give details………………………………….……………………………………………………………………………………………………………………………………………………………………

7. Are you presently taking any form of medication? Yes / NoIf you answered Yes, please give details………………………………….……………………………………………………………………………………………………………………………………………………………………

8. As far as you are aware, do you suffer or have you ever suffered from:

a Diabetes? Yes / No b Asthma? Yes / Noc Epilepsy? Yes / No d Bronchitis? Yes / Noe *Any form of heart complaint? Yes / No f Raynaud’s Disease? Yes / Nog *Marfan’s Syndrome? Yes / No h *Aneurysm/embolism? Yes / NoI Anaemia Yes / No

9. *Is there a history of heart disease in your family? Yes / No

10. *Do you currently have any form of muscle or joint injury? Yes / No If you answered Yes, please give details………………………………….………………………………………………………………………………………………………………………………………………………………. …..

11. Have you had to suspend your normal training in the last two weeks? Yes / NoIf the answer is Yes please give details…………………………………………….…………………………………………………………………………………………..…………………………………………………………………………………………..

If blood is not being taken from you please disregard Section 12. below.

12. * Please read the following questions:a) Are you suffering from any known serious infection? Yes / Nob) Have you had jaundice within the previous year? Yes / Noc) Have you ever had any form of hepatitis? Yes / Nod) Are you HIV antibody positive Yes / Noe) Have you had unprotected sexual intercourse with any

person from an HIV high-risk population? Yes / No



f) Have you ever been involved in intravenous drug use? Yes / Nog) Are you hemophiliac? Yes / No

13. As far as you are aware, is there anything that might prevent you fromsuccessfully completing the tests that have been outlined to you? Yes / No

IF THE ANSWER TO ANY OF THE ABOVE IS YES THEN:a) Discuss the nature of the problem with the Principal Investigator. b) Questions indicated by ( * ) Allow your Doctor to fill out the ‘Doctors Consent

Form provided.

As far as I am aware the information I have given is accurate.

Signature: ……………………………………………………………...

Signature of Parent or Guardian if the subject is under 18:

………………………………………………………………... ... ... ... ...

Date: ……/……/……



Appendix 4. Informed consent form

PARTICIPANT CONSENT FORM

TITLE OF RESEARCH STUDY:

Please answer the following questions by ticking the response that appliesYES NO

1. I have read the Information Sheet for this study and have had details of the study explained to me.

2. My questions about the study have been answered to my satisfaction and I understand that I may ask further questions at any point.

3. I understand that I am free to withdraw from the study within the time limits outlined in the Information Sheet, without giving a reason for my withdrawal or to decline to answer any particular questions in the study without any consequences to my future treatment by the researcher.

4. I agree to provide information to the researchers under the conditions of

confidentiality set out in the Information Sheet.

5. I wish to participate in the study under the conditions set out in the Information Sheet.

6. I consent to the information collected for the purposes of this research study, once anonymised (so that I cannot be identified), to be used for any other research purposes.



Participant’s Signature: _________________________________________ Date: _____

Participant’s Name (Printed): ____________________________________

Contact details: ________________________________________________________________

_________________________________________________________________________

Researcher’s Name (Printed): ___________________________________

Researcher’s Signature: _______________________________________

Researcher's contact details:(Name, address, contact number of investigator)

Please keep your copy of the consent form and the information sheet together.

Appendix 5. VAS questionnaire.

How severe is your soreness in your Quadriceps muscle group? Please place a vertical mark on the line below to indicate how bad you feel your soreness is. Please see figure 1 to locate the quadriceps group.

No Pain Severe Pain

How severe is your soreness in your Hamstring muscle group? Please place a vertical mark on the line below to indicate how bad you feel your soreness is. Please see figure 2 to locate the Hamstring group.

No Pain Severe Pain

How severe is your soreness in your Calf muscle group? Please place a vertical mark on the line below to indicate how bad you feel your soreness is. Please see figure 3 to locate the calf group.



No Pain Severe Pain

How severe is your soreness in your Tibialis Anterior muscle group? Please place a vertical mark on the line below to indicate how bad you feel your soreness is. Please see figure 4 to locate the Tibialis Anterior group.

No Pain Severe Pain

Figure 1. Location of the quadriceps muscle group. Muscle group can be found in the upper legs at the front of the leg.

Figure 2. Location of the Hamstring muscle group. Muscle group can be found in the upper legs at the back of the leg.



Figure 3. Location of the Calf muscle group. Muscle group can be found in the lower legs at the back of the leg.

Figure 4. Location of the Tibialis anterior muscle group. Muscle group can be found in the lower legs at the front of the leg.

Appendix 6. Risk Assessment Form

Faculty of Health and Wellbeing Research Ethics CommitteeSport and Exercise Research Ethics Review Group

Risk Assessment Pro Forma

**Please ensure that you read the accompanying Risk Assessment Risk Ranking document before completing this form**

Title of research

The effects of tart cherry supplementation on muscle damage, muscle force regeneration and perceived muscle soreness in untrained males and females following isokinetic dynamometry.

Date Assessed 29/11/2014

Assessed by (Principal Investigator) Ryan Till



Signed PositionPrincipal Investigator

Activity Risks Control Measures

Put in this box the activity which may cause harm.

Risk of [place in here the harm that may be caused] caused by [put in the hazard (source of danger) here]. Risk = consequence x likelihood. Identify risk category Low Medium or High

Place here what you would do to minimise the risk

Blood test Risk of [fainting, vomiting, seizuring, falling into things] caused by [blood phobia]. R3 = C1 x L3. MEDIUM RISK

Risk of [bacterial/viral infection] caused [break in skin/contaminated equipment]. R3 = C3 x L1. MEDIUM RISK

Ask participants if anyone has a blood phobia prior to taking blood.

Cover up the open wound site and use clean equipment.

Isokinetic dynamometer

Risk of [Musculo-skeletal injury] caused by [knee extension and flexion]. R2 = C2 X L1. LOW RISK

Warm up sufficiently.

Consumption of tart cherry supplement and cherry cordial placebo

Risk of [allergic reaction] caused by [Different cherry concentrate consumed]. R2 = C2 x L1. LOW RISK

Ask prior to testing whether participants have any known allergies.

Risk Evaluation (Overall)

Medium

General Control Measures



Is a pre-screen medical questionnaire required? Yes [ x ] No [ ]

Pre-screen medical questionnaire for evaluation of fitness and health, to see whether they can participate in the DOMS inducing exercise and safely give a blood sample.

Recruit subjects who have a relatively injury free history.

Ask prior to study If anyone has any allergies.

Any equipment with blood on shall be thrown away, only clean equipment shall be used and plasters/tissues shall be used to cover puncture in the skin.

Emergency Procedures

1. Alert emergency services if adverse reactions to supplement or cardiovascular complications occur

2. Cease exercise if personal injury / discomfort arises from exercise performance.3. Alert first aid trained personnel if necessary.

Monitoring Procedures

Keep an eye on individuals after giving blood samples to ensure they feel okay.

Review Period

Reviewed By (Supervisor) Date



Appendix 7. Ethics Forms


Documents

Dissertation Finished