HRV for Runners: What Your Heart Rate Variability Actually Means

Your Garmin tracks HRV every night. Here's what those numbers mean and how to use them.

What is Heart Rate Variability?

Heart rate variability (HRV) measures the variation in time between consecutive heartbeats. If your heart beats 60 times per minute, it's not perfectly once per second. The tiny fluctuations between beats reflect how well your autonomic nervous system is functioning.

Higher HRV generally means your body is in a better recovery state. Your parasympathetic (rest and digest) nervous system is active, and your body is ready to adapt to training stress. Lower HRV suggests your body is still dealing with stress, whether from training, poor sleep, illness, or life in general.

Why Higher HRV is Generally Better

Important: HRV is individual. Your baseline might be 45ms while another runner's is 80ms. What matters is YOUR trend, not comparing to someone else.

What Affects HRV

• Training load - Hard workouts temporarily lower HRV. This is normal. It should bounce back within 24-48 hours.
• Sleep - The single biggest factor. Poor sleep or inconsistent sleep times tank HRV.
• Alcohol - Even moderate drinking suppresses HRV for 24-48 hours.
• Stress - Work stress, relationship stress, financial stress. Your nervous system doesn't distinguish between running stress and life stress.
• Hydration and nutrition - Dehydration and underfueling both lower HRV.
• Illness - Dropping HRV can be an early warning sign that you're fighting something off.
• Fitness - Over months and years, consistent training raises your baseline HRV.

How Garmin Measures HRV

Garmin measures HRV overnight using the optical heart rate sensor on your wrist. It captures beat-to-beat intervals during sleep, when movement artifacts are minimized and readings are most reliable.

You'll see your HRV Status in Garmin Connect, which shows a 7-day average and whether you're in a "balanced," "low," or "optimal" range relative to your personal baseline. The overnight measurement is more consistent than spot-check readings during the day.

Normal HRV Ranges by Age

These are general population ranges. Runners and endurance athletes typically fall on the higher end.

Age Range	Average HRV (ms)	Athletic Range (ms)
20-29	40-80	60-100+
30-39	35-70	50-90
40-49	30-60	45-80
50-59	25-50	35-70
60+	20-40	30-55

Again, the absolute number matters less than your personal trend. A 55-year-old with a consistent HRV of 38ms who sees it drop to 28ms for three days should pay attention, regardless of where that falls on a chart.

How to Use HRV Trends for Training Decisions

Common Mistakes Runners Make with HRV

• Reacting to a single day. One low reading means nothing. Look at 3-7 day trends.
• Comparing to other runners. HRV is deeply individual. Your 45 might be someone else's 80.
• Ignoring context. A low HRV after a race or a hard long run is expected. A low HRV after a rest day is more concerning.
• Not measuring consistently. Wear your watch every night. Gaps in data make trends unreliable.