Heart Rate Variability (HRV) for Improved Sports Performance
Ronda Collier
SweetWater Health
Who Am I? Ronda Collier, B.S.E.E., M.A. Psychology
• Ronda is currently CEO of SweetWater Health and has more than 25 years of experience in high technology product development. She spent 3 years as an independent scholar researching non-invasive health monitoring techniques which led to the founding of SweetWater Health in 2011 and the release of SweetBeat, the HRV measurement app in 2012.
• Ronda has presented HRV basics and applications at the 2012 and 2013 Quantified Self conference and SweetBeat was featured at the 2012 Health 2.0 conference in San Francisco. In addition, she has been interviewed by several popular podcast hosts, including sports physiologist and author Ben Greenfield, and The Bulletproof Executive’s Dave Asprey. She is known for presenting HRV in a simple and understandable fashion.
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Introduction Most athletes know that getting enough rest after exercise is essential to high-level performance
• Still many over train and feel guilty when they take a day off
Continuous training can actually weaken the strongest athletes
• Rest is physically necessary so that the muscles can repair, rebuild and strengthen
Standardized training programs produce well documented results however they do not take individual responses into account
• Age, gender, race, baseline fitness level and genetic factors are known determinants of individual differences in responses to endurance training*
The status of the Nervous System is an important indictor of training response
• Nervous System measures indicate individual responses
Heart Rate Variability (HRV) is a view into the nervous system
• HRV is reflection of vagal tone which is affected by overtraining
• HRV can be used to guide an optimal training program
• HRV is non-invasive and can be measured with an off the self chest strap
*(Bouchard et al. 1999; Bouchard and Rankinen 2001; Rankinen et al. 2003)
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The Science of HRV What is Heart Rate Variability
(HRV)?
What does a healthy HRV look like?
HRV in the mainstream
HRV in the mainstream
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HRV and Vagal Tone
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The Vagus Nerve is the 10th of 12 paired cranial nerves and controls parasympathetic innervation of the heart and acts to lower the heart rate.
Vagal innervation is the mediator of HRV and therefore HRV is an indication of Vagal Tone
The higher the HRV, the stronger the Vagal Tone
Higher HRV is an indication of an individuals ability to “put the brakes on stress” by mediating the sympathetic control over the nervous system and heart rate.
The Sympathetic/Parasympathetic Nervous System The Autonomic Nervous System (ANS) consists of:
• Sympathetic “Fight or Flight” Branch
• Parasympathetic “Rest and Repair” branch
These two branches of the ANS can be measured using HRV analysis
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RR Intervals Defined
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HRV calculations are performed on the “RR interval time series”. What exactly is that?
• ECG “R” point can be though of as the beat time
• The R-R interval is the time between beats
The resulting “RR interval time series” looks something like this:
0.978516
0.982422
1.06641
1.06738
0.974609
1.05273
1.08887
0.974609
0.961914
1.04688
1.02734
HRV Can Be Measured in Multiple Ways
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Statistical Analysis Standard Deviation (SDNN)
RR intervals have also been called NN intervals which is why SDNN instead of SDRR
NN stands for Normal to Normal
Root Mean Square of Successive Differences, (rMSSD)
pNN50, TINN, Triangular index
Frequency analysis of RR intervals
Very Low Frequency (VLF)
Low Frequency (LF, associated with sympathetic activation)
High Frequency (HF, associated with parasympathetic activation)
Non-Linear
• SD1/SD2, ApEn, SampEN
HRV Parameters of Interest: rMSSD
rMSSD is a reflection of Vagal Tone
rMSSD is non-stationary and varies +/- 10 ms at rest
Average rMSSD ranges from ~20ms to ~80ms depending on age and state of health
Generally calculated on 5 minute window
Used in clinical research for HRV and performance training
Most consumer HRV applications provide a number 0-100 based on rMSSD
Each application uses a slightly different scaling algorithm so it is important to choose one and stick with it
A high HRV (rMSSD) is an indication of health and training recovery
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HRV Parameters of Interest: LF/HF
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LF is associated with sympathetic nervous system
HF associated with parasympathetic nervous system
There are industry standards for LF and HF frequency ranges
LF = 0.04hz - 0.15Hz HF = 0.15hz – 0.4hz
LF and HF units are Power Power also called Spectral
Density
LF and HF Ratio is another standard of measure LF/HF < 2 is indication healthy
stress levels
HRV Additional Information HRV is an indication of your resilience – the ability of the nervous
system to respond and recover from physical or psychological stressors
IMPORTANT: HRV values depend on length of measurement
5 Minutes = Short term HRV
24 Hour = Long term HRV
IMPORTANT: HRV is age and gender dependent
HRV has a circadian rhythm
HRV may change day to day with your biorhythm or due to emotional or physical stress
Chronic low HRV is an indication of systemic health (psychological or physical) issues
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HRV Interpretation
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HRV can vary greatly from person to person depending on health and fitness
HRV can vary greatly for an individual from day to day and even hour to hour
While there are “average HRV values” determined through clinical research, HRV is dynamic and individuals will tend to have their own range
Some athletes have HRV values that are magnitudes higher than average persons
Athletes use HRV to guide training
• Source: http://www.sciencedirect.com/science/article/pii/S0735109797005548
• Values based on 24 hour measurements• HRV represents rMSSD scaled to a value between 0 – 100 and is
SweetBeat specific
Gender Age Average HRVMale 10-29 72.29827Female 67.68875Male 30-49 62.51162Female 60.47521Male 50-69 52.91486Female 55.733Male 70-99 52.91486Female 52.91486
HRV for Training: When and How to Measure
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HRV has a circadian rhythm
HRV is dependent on body position
HRV value is dependent on length of measurement
Therefore
• HRV taken at same time each day
― First thing in the morning is recommended
• In same position
― Lying down
― Sitting
― Standing
• Measurement for same length of time each day (3 minutes typical)
6am 12pm 6pm 12am
Circadian Rhythm
HRV
Time of Day
HRV for Training Example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 2370
75
80
85
90
95
100
105
Ben G.
Daily HRVReference
Low Exertion Day Recommended
Rest Day Recommended
Good Recovery Proceed or Increase
Good HRV Proceedwith training
Low Exertion Day Recommended
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Guided Training Flow Chart Example
Source: Endurance training guided individually by daily heart rate variability measurements . Kiviniemi et al. 2007
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HRV* for Elite Triathlete
*HRV measured using SweetBeat
60
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75
80
85
90
95
100
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88 91 94 97 100 103
HRV
HRV
Linear (HRV)
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HRV* for Fitness Enthusiast
*HRV measured using SweetBeat
40
50
60
70
80
90
100
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75
HRV
HRV
Linear (HRV)
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LF, HF Power, Elite Athlete
0
2000
4000
6000
8000
10000
12000
14000
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
LF
HF
Day of first racehigh cortisolmeasure day before
Tuesday afterrace high cortisolmeasured
LF vs. HF Elite Athlete
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LF, HF Power, Fitness Enthusiast
0.00
1000.00
2000.00
3000.00
4000.00
5000.00
6000.00
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
LF
HF
LF vs. HF Fitness Enthusiast
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Stress, Food, HRV and Optimal Performance
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Inflammation is a common reaction to a hardcore work out and is part of the recovery process
Inflammation is an innate response to stress, illness, poor gut function or eating toxic foods
• Stress increases cortisol which contributes to inflammation
What causes stress for one person will not cause stress for another
• Same thing goes for food
• Individuals need to track what works and doesn’t for them
Interdependence of our body functions make it complicated
Source: http://robbwolf.com/2012/04/09/real-deal-adrenal-fatigue/
“It’s Complicated”
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When this response becomes the norm for your body, whether it is from workouts, stress or food, it becomes a low-level feature in your physiology
Syphilis
• Mild, chronic, inflammation produces few symptoms and subtle changes on blood tests, though has a very different effect on your metabolism
• Chronic low-grade inflammation makes your brain and body resistant to the normal regulatory effects of hormones, including insulin and cortisol
• It interferes with recovery and thus optimal performance
It is recommended that stress and diet be monitored in addition to HRV for optimal performance
Source: http://www.integrativepsychiatry.net/adrenal_fatigue.html
Tools of the Trade
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SweetWater Health’s SweetBeat and SweetBeatLife iPhone applications
• HRV for Training functionality
• Real time stress monitoring
• Food Sensitivity testing
• LF and HF measurements
HRV for Training includes training recommendations based on clinical research
www.BeatHealthy.com
@Beathealthy
BeatHealthy
And Better Yet…
SweetBeat and SweetBeatLife now* work seamlessly with Restwise recovery program• HRV and Resting Heart Rate automatically entered into Restwise when
SweetBeat session is uploaded
• HRV may be displayed in relation to recovery score and any of the other RestWise metrics
www.restwise.com @restwise Restwise
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