HRV Training Guide: Your Nervous System's Report Card
Heart rate variability tells you what your body can handle today—before you push too hard or leave gains on the table. Here's how to use it.
Founder, Eyes Up
- HRV measures how adaptable your nervous system is—high and stable means you're recovered; low and dropping means back off
- Measure in the morning, same time, same position—consistency matters more than the absolute number
- Use the 7-day rolling average—single-day readings are noisy; the trend tells the real story
- Sleep, hydration, stress, and alcohol are the biggest levers—fix these and HRV follows
What Is Heart Rate Variability?
Your heart doesn't beat like a metronome. If your heart rate is 60 bpm, that doesn't mean exactly 1 second between each beat. The time between beats varies—maybe 0.95 seconds, then 1.05 seconds, then 0.98 seconds.
This variation is heart rate variability (HRV). It's controlled by your autonomic nervous system—the same system that handles stress response, digestion, and recovery. HRV is a window into how well that system is functioning.
The Two Branches
Your autonomic nervous system has two branches: sympathetic (fight or flight—accelerates heart rate) and parasympathetic (rest and digest—slows heart rate). High HRV means these systems are well-balanced and responsive. Low HRV often means sympathetic overdrive—your body is stressed and less adaptable.
The most common HRV metric is RMSSD (root mean square of successive differences)—it measures beat-to-beat variation and reflects parasympathetic activity. When wearables report your HRV, they're typically showing RMSSD in milliseconds.
Why HRV Matters for Football Players
Training is stress. Practice is stress. Games are stress. Your body adapts to stress during recovery—but only if you give it time. The problem: you can't feel when your nervous system is overloaded. HRV lets you see it.
High, Stable HRV = Green Light
- • Body is recovered and adaptable
- • Ready for high-intensity training
- • Stress capacity is high
- • Immune function is strong
Low, Dropping HRV = Caution
- • Sympathetic nervous system overloaded
- • Modify training or rest
- • Higher injury risk
- • Possible early illness signal
HRV Drops Before You Feel It
Research shows HRV decreases before you feel overtrained or get sick. It's an early warning system. By the time you feel exhausted, you've already been running on empty for days. Check your HRV before it gets that far.
Studies on professional soccer players found that HRV can discriminate between international-level and national-level players—elite players had higher parasympathetic activity and better recovery capacity. HRV isn't just about avoiding overtraining; it's a marker of your body's ability to handle elite-level stress.
How to Measure HRV Correctly
Consistency beats precision. The exact number matters less than measuring the same way, at the same time, in the same position, every day. That's what makes the data useful—you can see real changes instead of measurement noise.
The Morning HRV Protocol
Consistency beats precision. Same time, same position, same routine.
Wake Up Naturally
Same time every day (±30 min)Use a consistent alarm time. Your HRV is most reliable when measured at the same time daily.
Tip: Weekend sleep-ins of 2+ hours will skew your data. Try to keep wake time within 1 hour of your weekday schedule.
Wait Before Moving
30-60 seconds after wakingStay in bed or sit up slowly. Avoid checking your phone, scrolling, or getting stressed about the day.
Tip: If you use an Oura ring, your overnight HRV is already captured. WHOOP users should wait for the morning reading.
Take the Measurement
1-3 minutesOpen your app and follow the measurement protocol. Sit upright with feet flat if doing a manual reading.
Tip: Lying down gives different values than sitting. Pick one position and stick with it forever.
Breathe Naturally
Throughout measurementDon't try to control your breathing. Avoid coughing, yawning, or swallowing during the measurement.
Tip: Forced slow breathing will artificially inflate your HRV. Let it be natural.
Log Context
After measurementNote anything relevant: how you slept, alcohol last night, stress levels, training yesterday.
Tip: A single HRV number is meaningless without context. The trend + context tells the story.
Why morning? Sleep is a parasympathetic state—morning measurements capture your baseline physiology after the restorative effect of sleep, before daily stressors accumulate. Research shows morning HRV detects overtraining better than nighttime readings.
Measurement Frequency
Aim for 4-7 days per week. Single measurements are noisy—your 7-day rolling average is what matters. Research shows weekly averages and coefficient of variation (CV) are far more useful than daily readings for understanding recovery status and making training decisions.
What Your HRV Is Telling You
Don't obsess over a single number. Look at patterns: your baseline, the 7-day trend, and whether values are stable or swinging wildly. Here's how to interpret what you're seeing:
Your nervous system is well-recovered. Parasympathetic dominance indicates readiness for stress.
Green light for high-intensity training. This is when to push: heavy lifts, speed work, competitive scrimmages.
Your 7-day average is 65ms with <3% variation. Yesterday was a rest day, HRV is 68ms this morning.
The Context Matters
HRV in isolation can be misleading. A low reading after a hard practice is expected—that's normal adaptation. A low reading after a rest day with good sleep? That's a signal. Always pair HRV with context: sleep quality, training load, life stress, hydration, and how you actually feel.
What Increases and Decreases HRV
HRV captures how your body is responding to life—not just workouts. These are the major factors. Fix the basics (sleep, hydration, stress management) and HRV improvements follow.
Sleep
- +7-9 hours of consistent sleep
- +Same bedtime/wake time
- +Cool, dark room (65-68°F)
- −Sleep deprivation (<6 hours)
- −Inconsistent sleep schedule
- −Poor sleep quality (low deep sleep)
Hydration
- +Adequate daily water intake
- +Electrolyte balance
- +Consistent hydration habits
- −Dehydration (even mild)
- −Electrolyte imbalance
- −Morning HRV reflects yesterday's hydration
Training Load
- +Appropriate training stimulus
- +Adequate recovery between sessions
- +Progressive overload with rest
- −Overtraining / insufficient recovery
- −Multiple high-intensity days in a row
- −Ignoring low HRV signals
Mental Stress
- +Stress management practices
- +Breathing exercises (6 breaths/min)
- +Mindfulness / meditation
- −Academic stress (finals week)
- −Relationship / life stress
- −Anxiety and rumination
Alcohol
- +Avoiding alcohol entirely
- +48+ hours since last drink
- −Any alcohol consumption
- −HRV suppressed 2-3 days after drinking
- −Effect is dose-dependent
Illness / Immune
- +Healthy immune function
- +No active infections
- −Coming down with illness
- −Fighting infection (even mild)
- −HRV drops before you feel sick
The 80/20 of HRV Improvement
Most HRV improvement comes from three things:
- Sleep 7-9 hours consistently at the same times
- Stay hydrated—morning HRV reflects yesterday's hydration
- Don't overtrain—if HRV is down for 3+ days, rest
HRV-Guided Training: How to Use the Data
The research is clear: HRV-guided training—adjusting intensity based on your daily readiness—produces better results than rigid, pre-planned programs. Not by a huge margin, but it matters for avoiding overtraining and optimizing adaptation.
The Decision Framework
HRV within or above your normal range
Train as planned. High-intensity work, heavy lifts, competitive practice. This is when adaptation happens—push it.
HRV slightly below normal (1 day)
Proceed with caution. Consider reducing volume or intensity by 20-30%. Focus on technique over max effort. Monitor closely.
HRV below normal for 2+ days
Back off. Active recovery, mobility work, walking only. Prioritize sleep and hydration. Resume normal training when HRV rebounds.
Don't Overreact to Single Days
A single low HRV reading doesn't mean skip practice. The 7-day rolling average is your guide. If yesterday was intense and today's HRV dropped, that's expected. But if you're seeing 3+ consecutive days below baseline despite normal training and good sleep—that's a real signal.
Game Week Application
Use HRV to optimize tapering. As game day approaches:
- •Monday-Tuesday: Normal HRV readings expected after weekend rest
- •Wednesday-Thursday: May see slight dip from practice load—normal
- •Friday: HRV should be recovering; if still suppressed, extra rest before game
- •Game Day: A slight stress response is normal and even helpful—you want some activation
Wearables for HRV Tracking
Any validated wearable is better than no tracking. The key is picking one and sticking with it—device consistency matters more than device accuracy. That said, here's how the major options compare:
Oura Ring
- • Measures overnight HRV continuously
- • Strong accuracy at resting HRV
- • Finger measurement = less noise
- • Best for: sleep + recovery focus
- • Note: Accuracy may decrease at very high HRV (>100ms)
WHOOP
- • 24/7 monitoring with strain tracking
- • Excellent readiness context
- • 99% accuracy in validation studies
- • Best for: athletes who want training load integration
- • Note: Subscription model, no screen
For a detailed comparison of these devices, including sleep tracking and recovery metrics, see our Oura vs WHOOP comparison guide.
The Best Device Is the One You'll Use
Both Oura and WHOOP are validated for HRV tracking. Chest straps (Polar H10) are the gold standard for accuracy but require active measurement. Wrist-based devices (Apple Watch, Garmin) are less accurate at rest but improving. Pick what fits your life and commit to using it daily.
Frequently Asked Questions
Frequently Asked Questions
Track HRV With Your Team
EYES UP gives coaches visibility into player HRV and recovery status—so you can make training decisions based on data, not guesswork.
Learn More