Does exercise increase HRV?
Yes, over months. Regular aerobic training raises resting HRV, and in 8 million Fitbit users, people who took more steps a day had higher HRV at every age. Each hard session lowers it for a day or two first. The rise comes from the recovering.
People start running, watch their HRV fall for a week and decide exercise is hurting them. That dip is the session’s cost, paid back over the next day or two. The gain shows up in the average over weeks and months.
Think of it like a savings account with withdrawals. Each hard session takes a little out. Recovery puts it back with a bit extra. Look at the balance once a week, not after every withdrawal.
What we’d do: walk, cycle, swim or run most days, mostly at an easy pace, with one or two hard sessions a week. Judge the effect on your 7-day average after a couple of months.
What the studies show
| Study | Who | Finding |
|---|---|---|
| 13 training studies, pooled, 2005 | 322 people | Training raised a vagal HRV measure, a moderate effect. Responses tended to be smaller in older people |
| 8,203,261 Fitbit users, 2020 | Adults of all ages | More daily steps went with higher HRV, step by step, at every age and in both sexes |
| 27 studies of athletes, 2016 | Endurance athletes | When training made them faster, resting RMSSD rose a little |
| Recovery after one session, 2013 | Athletes and healthy adults | Up to 24 hours after easy exercise, 24 to 48 hours after moderately hard, 48 hours or more after very hard. Fitter people recovered faster |
In a 2026 study of 90 people wearing Garmin watches, a group of recreational runners had a median RMSSD of 47 ms, against 42 ms in people with no regular exercise.
How sure are we?
Strong for the direction. Training raises resting HRV in trials, and the large observational data agree. The size varies a lot from person to person, and it shrinks with age. A rise over months on the same device is a good sign. A sudden jump during a very hard block can mean something else, so see is a higher HRV always better?
5 sources
- Sandercock GR, Bromley PD, Brodie DA, Effects of exercise on heart rate variability: inferences from meta-analysis, Medicine and Science in Sports and Exercise, 2005pubmed.ncbi.nlm.nih.gov
- Natarajan A et al., Heart rate variability with photoplethysmography in 8 million individuals: a cross-sectional study, Lancet Digital Health, 2020pubmed.ncbi.nlm.nih.gov
- Bellenger CR et al., Monitoring athletic training status through autonomic heart rate regulation: a systematic review and meta-analysis, Sports Medicine, 2016pubmed.ncbi.nlm.nih.gov
- Stanley J, Peake JM, Buchheit M, Cardiac parasympathetic reactivation following exercise: implications for training prescription, Sports Medicine, 2013pubmed.ncbi.nlm.nih.gov
- Takezawa J et al., Daily stress and heart rate variability among mindfulness meditation practitioners, Journal of Medical Internet Research, 2026pubmed.ncbi.nlm.nih.gov
