SPORTS DRINKS

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SPORTS DRINKS

All text tables, copyright Health Equalities Group 2017

Primary authors:

Michael Viggars, MA

Health Equalities Group151 Dale StreetLiverpoolL2 2JHUnited Kingdom

www.giveuplovingpop.org.uk@gulpNOW

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CONTENTS

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Foreword

Introduction

Emergence of the Sports Drink Industry

Convergence of the Sports Drink Industry

Types of Sports Drinks

Performance Enhancement

Critique of the Sports Drink Industry

Sports Drink Research & Misconceptions

Sports Drinks Marketing

Recommendations

References

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Drinking sports drinks can hinder

WEIGHT LOSS

EDUCATIONALATTAINMENT

SPORTINGPERFORMANCE

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FOREWORD

Sports drinks are a relatively recent phenomenon, yet anatomically modern humans

have been running around for some 200,000 years. So why do we need them?

The producers of sports drinks keenly emphasise that their products optimise

hydration before, during and after physical activity and may even be better than

water but the evidence is tenuous.

Many issues have been raised with how and why the sports drink industry conducts

its research. Sports drinks are routinely tested on highly trained young men in

laboratory settings and therefore any results cannot be generalised to an inactive,

sedentary population.

Experts have concluded that for the general public, water and a balanced diet is all

that is required to facilitate regular exercise.

Michael Viggars

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Introduction

Sports drinks are a particular type of softdrink that are usually rich in carbohydrates(in the form of sugar), minerals, electrolytesand flavourings and are alleged to optimisehydration before, during and / or afterphysical activity and improve athleticperformance. They are not to be confusedwith energy drinks such as Red Bull orMonster, which contain high concentrationsof caffeine designed to increase alertnessand fend off drowsiness.

In contrast to energy drinks, sales of sportsdrinks appear to be in decline in the UK,peaking at 165 million litres sold in 2011,falling to 150 million litres in 2013 adecrease of just over 9%. This may beattributed to the aggressive marketingstrategies of energy drinks targeting thesame consumer group as the sports drinkindustry.

Emergence of the Sports Drink Industry

In 1965, Dr. Robert Cade, assistant professorin the renal division of the College ofMedicine at the University of Florida, wascontacted by Dewayne Douglas, assistantcoach of the Florida Gators Freshmanfootball team, after 25 American footballplayers had been admitted to the hospitalinfirmary the previous weekend due to heatexhaustion and dehydration.

Douglas needed something tothe strain that the brutal summer heat hadinflicted upon his . Cadesupposedly knew that replacing fluids wouldbe a true advantage for the team hardly ascientific approach as the loss offluids through sweating led to dehydration,salt depletion and in some cases heatstroke.

They found that adding glucose to a salt-water solution increased the rate at which

both sodium and water were absorbed bythe small intestine. Naturally, theyconcluded that a drink containing glucoseand sodium would be valuable to athletesrequiring instant rehydration.

The physiological hunch that theirprototype, lemon-tinged, glucose-saltsolution would benefits the Gators paid off.The drink was given to players in a gameversus the heavily favoured Louisiana State,ranked fifth in the country. The University ofFlorida Gators came from behind to win 14-7. Gatorade was born.

Convergence of the Sports DrinkIndustry

In an interview in 2005, Dr. Robert Cadesaid:

never thought about the commercialmarket. The financial success of thisstuff really surprised us. I am proud thatGatorade was based on research intowhat the body loses in exercise. Theother sports drinks were created bymarketing companies. [1].

Whilst Gatorade appears to have beencreated with honest intentions, a quicklydeveloping market saw several competitorsenter due to the commercial potential.Gatorade currently dominates the NorthAmerican sports drink market, holding a77.2% share to 21.7% [2], ashare they undoubtedly wish to maintain.

When considering the UK market, energydrinks such as Red Bull are often considereda type of sports drinks, and frequently claimto benefit the consumer in similar ways. Tolearn more about energy drinks, please seeour energy drinks briefing.

Contrary to Dr. statement, the mostcommon UK sports drink Lucozade Sportbegan life as and was designed

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In 1927 by William Owen, a Newcastlechemist, as a source of energy for peoplesuffering from illnesses such as the commoncold and influenza.

Following a major rebrand in the 1980s,brought on in part by the commercialsuccess of Gatorade across the pond,Lucozade shook off the

label and began targetingyoung people rather than -at-home

tripling their sales to £75 million inthe process. Their slogan changed from

aids toreplaces lost taking on a broadermeaning and opening up new markets.

Types of Sports Drinks

There are three main classifications of sportsdrinks containing various concentrations offluid, electrolytes and carbohydrates.

The rationale is that different athletescompeting in different sports have differentneeds before, during and after exercise; andtherefore sports drinks are tailored to matchexact specifications.

Isotonic

These drinks containing similarconcentrations of salt and sugar as in thehuman body. This allows replenishment offluids lost through sweating and supplies aboost carbohydrate. Isotonic drinks are thepreferred choice for the vast majority ofathletes, including middle and long-distance runners and those involved in teamsports. These are the most commerciallyavailable of sports drinks.

Hypertonic

Hypertonic drinks contain a higherconcentration of salt and sugar than thehuman body and are normally consumedpost-workout to supplement dailycarbohydrate intake and top-up muscle

glycogen stores. They are occasionally usedin ultra-distance events to meet the highenergy demands but most are used in withwith isotonic drinks to replace lost fluids.

Hypotonic

Hypotonic drinks contain a lowerconcentration of salt and sugar than thehuman body, quickly replacing fluids lostthrough sweating. These drinks are suitablefor athletes who require rehydration withouta carbohydrate boost, such as gymnasts.

Performance Enhancement

Sports were initially conceived to be an aidto athletic performance and therefore it isnecessary to understand their constituentsand what they may offer during exercise.

Water

Water is abundant in the body, making up60% of our body mass, and serves many vitalfunctions, such as transportation of nutrientsand oxygen and removal of waste products,lubrication of joints and serves as a mediumfor chemical reactions in the body. Duringexercise, heat is produced during theprocess of converting chemical energy intomechanical energy; therefore to prevent usoverheating, we regulate our bodytemperature through sweating. As sweatevaporates, heat is released. This can alsoimpact the relative solute concentrations.

Sweat production as a consequence ofphysical activity can amount to 1 2 litres perhour, depending on exercise intensity,duration, clothing, air movement andhumidity [3]. Unless body water is replacedat appropriate times and in appropriateamounts we can become dehydrated. Evenmild dehydration (about 2% loss of bodyweight) can result in headaches, fatigue andreduced physical and mental performance[4].

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Sugar

The human body can derive energy from anumber of different sources includingcarbohydrates, fats and proteins. The rate atwhich energy can be produced from thesemacronutrients varies, and thereforedifferent energy sources are suitable fordifferent types of exercise.

At low to moderate intensity exercise thebody has enough time to break down fattyacids to produce energy. Even in a very leanindividual there is enough adipose tissueand muscle triglycerides (fats) to sustainexercise for several hours.

However, as physical exertion and energydemand increase, the body switches tocarbohydrate as the primary energy sourceof energy as it can be metabolised muchmore quickly although availability ofcarbohydrate is much lower and cannot besustained for extended periods of time.

The fact that carbohydrate can be brokendown to produce energy so quicklyprovides the rationale for their presence insports drinks.

Ultimately, glucose is the major useablesource of carbohydrate energy and can bemetabolised anywhere in the body and thatis why it is found in such vast quantities insports drinks.

Electrolytes

Before we can move, our brain has to send asignal through a nerve to a muscle or agroup of muscles asking it to contract; themuscle(s), which are attached to bones bytendons, then become shorter, pulling onthe bone, producing movement. Critically,the stimulus from the brain must be greatenough to generate an impulse to causecontraction of the muscle.

Without sufficient levels of sodium andpotassium our muscles cannot contractefficiently. When we sweat, sodium andpotassium are released giving sweat its saltytaste. Energy drinks contain electrolytes,which include sodium and potassium, andoccasionally calcium and chloride, allintended to prevent muscle fatigue.

However, sodium is secreted by thepancreas into the large intestine (wherewater is absorbed) and does not necessarilyneed to be supplemented. Cairns &Lindinger suggested that with moderateintensity exercise, the combined shifts ofsodium and potassium would be insufficientto cause fatigue. In fact, the body can detectfalling levels of sodium and potassiumconcentrations and increase blood flow tothis area, providing more of theseelectrolytes [5] - negating the need forsports drinks at this intensity.

Lucozade Sport Orange contains 32g of sugarper 500ml; the scientific advisorycommittee on nutrition (SACN) has recentlyrecommended cutting sugar intake by 50%. Thismeans that one bottle of Lucozade Sport willexceed recommended daily intakes of

for the majority of age groups.

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Critique of the Sports Drink Industry

Ultimately, sports drinks are a variety of softdrink and the harmful effects ofconsumption of sugar-sweetenedbeverages are well documented (see our

on briefing). However, sportsdrinks are alleged to perform a specificfunction that is to hydrate an individualbefore, during and / or after exercise andimprove athletic performance.

Several issues have arisen regarding theresearch methodologies used to supportthe claims made by sports drinks companiesas well as the claims themselves bending thetruth and misleading customers.

Interestingly, despite rebrandingexercise in the 1980s, the constituent partsof Lucozade Sport have remained largely thesame and not too dissimilar to Gatorade andPowerade. In fact, disregarding flavourings,Gatorade has changed very little in the 50years since its inception.

According to their marketing department,Gatorade is the most successful,most iconic and most scientificallyresearched sports drink and claims tohydrate athletes, replenish electrolytes andprovide fuel for working muscles [6]. Noakessuggests it is more accurate to state that:

Gatorade is the sports drink whoseeffects on the human body duringexercise have been the mostthoroughly .

A systematic assessment of the evidenceunderpinning sports performance productsconducted by Heneghan and colleagues(2012) asked manufacturers to supply detailsof the studies supporting their productclaims [7]. Only GlaxoSmithKline (thenowner of Lucozade) complied and supplieddata gathered from 1971 to 2012. Of the

176 studies supplied, only 106 could becritically reviewed.

Sports Drink Research & Misconceptions

Much of the research on sports drinks andtheir effect on metabolism is conducted onhighly homogenous groups of athletes withsimilar physiological measures. This meansthat whatever the outcome, the research canonly be applied to individuals matching theprofile of the participants in the study, and

be generalised to a largely sedentarypopulation. In other words, it is impossibleto know whether Lucozade will improvesporting performance in members of thegeneral public from the data collected.Heneghan and colleagues reported:

40 years of sports drinks researchdoes not seemingly add up to much,particularly when applying the resultsto the general public.

Heneghan surmised that themethodological issues identified with

research could be applied to allother sports drinks.

The Thirst Fallacy

There is a common misconception that thirstis not a good indicator of hydration, a fallacythat has leant itself well to the marketing ofsports drinks. Gatorade once said:

Your brain may know a lot, but itknow when your body is

[8] - leaving us all to wonder if thebrain figure out when we need a drink,what can?

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Click the boxes above to see first-hand how sports drink companies market theirproducts to children and adolescents.

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Urine Colour

Urine colour is sometimes proposed as asimple way to assess hydration status, withdarker urine representing dehydration andlighter urine characterising good hydrationstatus. Many sports drink manufacturers,including Lucozade, provide a colour chartto estimate your current hydration status (seeFigure 1 on the following page).

However, an examination of the evidence byHeneghan and colleagues found that nostudy has directly investigated thecorrelation between urine colour andperformance or the correlation betweenurine colour and thirst.

Urine colour should not be considered asthe sole determinant of hydration status. Thecombination of thirst, in addition to darkercoloured urine, provides a reasonableindication of dehydration.

Of those supporting the urine colour tool asa marker for hydration status, they admittedfindings could be compounded by sportsdrinks themselves, diluting the urinethrough excretion of excess sugars nodoubt a happy coincidence for sports drinkmanufacturers.

Recommendations

Before considering evidence-basedrecommendations it is important toremember that sports drinks are a relativelyrecent phenomenon yet anatomicallymodern humans have been running aroundfor some 200,000 years. So do we reallyneed them for their unsubstantiatedbenefits?

Hydration

Sedentary men are advised to consumeapproximately 2.5 litres of water per day,rising to 3.5 litres if they are moderatelyactive. Data on the amount of water women

should drink is lacking but due to their lowerbody mass, it is suggested that they shouldconsume 0.5-1 litre less than men [3].

Water is consumed from different sources,which include bottled water, tap water,beverages and the moisture contents offoods. Fruit and vegetables containbetween 80-95% water; fish (~75%), meats(~55%) and cheeses (45%).

However, there is so much variation in ourshapes and sizes and the types of activitythat we may or may not take part in making itvery difficult to suggest a size fitsamount. Drinking in response to our thirstmechanism is the best way to maintainhydration.

These values apply only to conditions ofmoderate environmental temperature andmoderate physical activity levels. Waterlosses incurred under extreme conditions ofexternal temperature and physical exercise,which can be up to 8000ml/day have to bereplaced with appropriate amounts. In suchinstances concomitant losses of electrolyteshave to be replaced adequately to avoidhypo-osmolar disturbances.

Reference Intake (RI) of water ml/day

Children

Male Female

6 12 months 800-1000

13 24 months 1100-1200

2 3 years 1300

4 8 years 1600

9 13 years 2100 1900

14+ years 2500 2000

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Energy

On a physiological level, after consuming ahigh-carbohydrate sports drink bloodglucose levels rise, insulin levels are elevatedand fatty acid availability is reduced [11]. Forsedentary individuals who do not have ahigh demand for energy, the spike in bloodsugar levels causes a cascade of reactionseventually resulting in the conversion ofglucose into fats. Long-term consumption ininactive individuals can cause weight gainand lead to obesity, type 2 diabetes andcardiovascular disease.

For individuals wanting to lose weight,drinking sports drinks may lead to extrahours in the gym as the body is beingfuelled by the carbohydrate present in thedrink rather than existing energy stores. Lowto moderate intensity physical activity isrecommended for those wanting to loseweight or for individuals starting aprogramme of exercise after an extendedperiod of physical inactivity.

Recovery

It is important to provide the body with the

right nutrients to refuel and recover afterexercise. If we our muscles may achefor extended periods and we may feellethargic and lack motivation.

Protein is essential for recovery, immunefunction and the growth and maintenance oflean body mass. In sedentary individuals,0.8 1.0g per kg bodyweight per day issufficient but in exercising individuals moreis required.

Trained individuals need 1.2 1.4g per kgbodyweight and strength athletes may needup to 2g per kg bodyweight per day inorder to see noticeable improvements in theshort term. Ideally protein should beingested within 1 2 hours after exercise tomaximise the benefits [13].

Milk has been put forward as a healthy post-exercise drink, providing protein, vitaminsand mineral and also hydration. A 200mlglass of semi-skimmed milk contains asmuch calcium as 63 Brussel sprouts, whichcontributes to the growth and maintenanceof teeth and bones and normal muscle andnerve function [14].

Figure 1.

This is the urine chartprovided byLucozade and comeswith the caveat:

This urine chartprovides an estimateof your hydrationstatus only. This site isnot a substitute forprofessional adviceand does not provideany medical services.You should alwayspromptly seekprofessional care ifyou have anyconcerns about yourhealth.

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REFERENCES

1. Transcript of interview with Dr. Robert Cade (Accessed 01/09/2015 from:http://www.huffingtonpost.com/huff-wires/20071127/obit-cade/)

2. Pepsi suing Coca-Cola over Powerade Ads (accessed 01/09/2015 from:http://www.huffingtonpost.com/2009/04/14/pepsi-suing-cocacola_n_186709.html)

3. EFSA. (2010). Scientific Opinion on Dietary Reference Values for Water.

4. SACN. (2015). Carbohydrates and Health.

5. Cairns, S. P., & Lindinger, M. I. (2008). Do multiple ionic interactions contribute to skeletal muscle fatigue?Journal of Physiology, 4039-4054.

6. Noakes, T. (2012). Waterlogged: The Serious Problem of Overhydration in Endurance Sports.

7. Heneghan, C., et al. (2012). The evidence underpinning sports performance products: a systematicassessment. BMJ Open, 2.

8. Heneghan, C., et al. (2012). Mythbusting sports and exercise products. (Accessed 01.09/2015 from:http://www.bmj.com/content/345/bmj.e4848)

9. Dion et al. (2013). Half-marathon running performance is not improved by a rate of fluid intake above thatdictated by thirst sensation in trained distance runners. European Journal of Applied Physiology.

10. Goulet, E. D. B. (2011). Effect of exercise-induced dehydration on time0trial exercise performance: a meta-analysis. British Journal of Sports Medicine, 45 (14), 1149-1156.

11. Horowitz, J. F., et al. (1997). Lipolytic suppression following carbohydrate ingestion limits fat oxidation duringexercise. American Journal of Physiology, 273, 768-775.

12. Benelam, B., & Wyness, L. (2010). Hydration and health: a review. Nutrition Bulletin, 36, 3-25.

13. BDA. (2014). Food Fact Sheet-Sport.

14. The Dairy Council. (2015). Milk Factsheet.

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All text tables, copyright Health Equalities Group 2017

Primary authors:

Michael Viggars, MA

Health Equalities Group151 Dale StreetLiverpoolL2 2JHUnited Kingdom

www.giveuplovingpop.org.uk@gulpNOW