Evidence on performance and recovery.
Most athletes already train their heart. Intervals, tempo work, and long sessions all build the engine. Far fewer train the system that decides how that engine behaves under load: the autonomic nervous system, which sets how quickly you settle between efforts, how well you recover overnight, and how steady you stay when the score is close. Heart rate variability (HRV) biofeedback is a way to train that system directly.
This article looks at what the research shows for athletes, where the evidence is still thin, and how to use HRV data without being ruled by it. Our athlete program applies the same approach with competitive and professional athletes.
HRV is the natural variation in time between heartbeats. A healthy heart does not beat like a metronome; it speeds up slightly as you breathe in and slows as you breathe out. Larger, well-organized swings generally reflect a nervous system that can shift gears: ramping up for effort, then returning to calm when the effort ends.
For an athlete, that capacity shows up in practical ways. It affects how fast heart rate drops between sprints, how deeply you rest after a hard block of training, and whether pressure in competition tightens the body or sharpens it. Physical training changes HRV over time, but it does not teach you to change your own state on demand. That is a separate skill, and it can be practiced.
HRV biofeedback trains you to breathe at your resonance frequency, usually somewhere between four and a half and six and a half breaths per minute. At that individual rate, heart rate, blood pressure, and breathing reinforce one another, and HRV swings become as large as they get. A sensor shows the heart rhythm in real time, so you can see what each breath does and learn to reproduce it.
The word individual matters. Resonance frequency differs from person to person, and it is measured, not guessed. Our HRV biofeedback program page explains how the rate is assessed and how training progresses.
A systematic review by Jiménez Morgan and Molina Mora (2017, Applied Psychophysiology and Biofeedback) found seven studies of HRV biofeedback in sport. Six reported improvements in performance-related measures, although every study was small, with between 1 and 30 participants.
A later meta-analysis by Pagaduan and colleagues (2022, Journal of Complementary and Integrative Medicine) pooled four randomized trials with 115 athletes aged 16 to 30. Biofeedback reliably changed breathing mechanics, slowing breathing rate. Its effect on resting HRV in athletes, however, was not yet established. That is a useful correction to marketing claims. Athletes often start with high resting HRV, so the main benefit may lie less in raising a baseline number and more in learning to use the system well under stress.
Several trials have tested HRV biofeedback when athletes face stress. Dziembowska and colleagues (2016, Applied Psychophysiology and Biofeedback) randomized 41 male athletes aged 16 to 21 to 21 days of portable HRV biofeedback or no intervention. The biofeedback group reported less anxiety and showed higher HRV and changes in brain activity patterns, while the control group did not change. The protocol also included positive emotional imagery, and there was no active comparison group, so the effect cannot be credited to breathing alone.
Deschodt-Arsac and colleagues (2018, PLoS One) followed sports students facing university examinations. Twelve practiced five minutes of HRV biofeedback twice a day for five weeks; six served as controls. Right after training, at exam time, the biofeedback group showed better autonomic markers but similar anxiety. Twelve weeks later, after practice had stopped, their autonomic markers were still higher and their anxiety was now lower. The physiology changed first, and the felt benefit followed.
In tennis, Makaracı and colleagues (2024, Perceptual and Motor Skills) randomized 16 international junior players to ten biofeedback sessions over four weeks or to no training. State anxiety fell and cognitive performance improved in the trained group. The program combined several biofeedback signals rather than HRV alone, and the sample was small, so it supports the general approach more than any single method.
For the competitive nerves side of this work, including how pre-performance anxiety responds to training, see our article on HRV biofeedback for performance anxiety.
Rijken and colleagues (2016, Applied Psychophysiology and Biofeedback) brought a peak performance program with daily HRV biofeedback into professional soccer and elite track and field. Soccer players improved on concentration and emotional control scales, along with a shift in HRV balance. This was a pilot with no control group, so it shows feasibility in a demanding environment rather than proof of effect.
Our own early work fits here. Lagos and colleagues (2008, Biofeedback) followed a 14-year-old competitive golfer through 10 weekly sessions of resonance frequency training. After training he shot a personal record for 18 holes, and his mean score was 15 shots lower than the previous season. A single case proves nothing on its own, but it shows the kind of carryover the larger trials have since tested.
Recovery is where athletes most hope for a shortcut, and the evidence calls for care. Raidl and colleagues (2026, International Journal of Sports Physiology and Performance) randomized 34 people doing four weeks of sprint interval training to add ten minutes of slow breathing after each session and at night, or not. The breathing group gained no extra performance, and their nighttime heart rate was slightly higher, by about three beats per minute. The title of the paper says it plainly: no evidence for slow breathing as a recovery strategy after sprint interval training.
A study of 13 national-level adolescent swimmers by Merlin and colleagues (2024, Journal of Functional Morphology and Kinesiology) adds nuance. Seven weeks of slow breathing at six breaths per minute, without biofeedback, improved recovery states, sense of control, and self-rated training performance. It did not change stress scores, heart rate, or HRV.
Read together, these studies suggest that a generic breathing routine at a fixed rate is not a recovery tool by default. Timing, dose, and an individually measured rate appear to matter, and that is the gap biofeedback is designed to close.
Sleep is the exception worth noting. In national-level athletes with sleep problems, Li and colleagues (2024, Applied Psychophysiology and Biofeedback) found that pre-sleep HRV biofeedback improved sleep efficiency more than EEG biofeedback did, and only HRV biofeedback improved reaction time. Our sleep and recovery program builds on that evening protocol.
Many athletes already track HRV with a wearable such as Oura, WHOOP, or a chest strap. That data is valuable as a gauge. Biofeedback is what moves the needle; the wearable tells you whether it moved.
Reading the gauge well takes some care. Plews and colleagues (2013, Sports Medicine) showed that in elite endurance athletes, single-day HRV readings can be misleading, partly because very fit athletes can show a saturation effect where HRV stops tracking fatigue cleanly. Their recommendation was to look at rolling averages over a week and to learn each athlete's individual pattern rather than reacting to one morning's number.
A meta-analysis by Manresa-Rocamora and colleagues (2021, International Journal of Environmental Research and Public Health) compared training guided by daily HRV with predefined training plans. HRV-guided training produced a moderate advantage in vagal HRV and only small, non-significant advantages in aerobic fitness and endurance performance. HRV is a good steering tool, not a guarantee of faster times.
The approach we use with athletes follows the evidence above.
First, measure resonance frequency in a supervised session rather than defaulting to six breaths per minute.
Second, practice in short, consistent daily blocks of 10 to 20 minutes with real-time feedback, especially in the first weeks while the skill is forming.
Third, rehearse the skill under load: between intervals, in a warm-up, or in a simulated pressure moment, so it is available in competition and not only on a quiet couch.
Fourth, track a seven-day rolling average of morning HRV on your wearable and read it alongside training load, sleep, and how you feel, rather than chasing a daily score.
Fifth, give it time. In the examination study above, the felt benefit arrived weeks after the physiological change.
Dr. Leah Lagos has more than 15 years of clinical experience with HRV biofeedback, works with professional and elite athletes, and has published research on its use in competitive sport. Her athlete program pairs individual resonance frequency assessment with a structured training plan built around your season. To learn more or request a consultation, visit the athlete program page.
Deschodt-Arsac V, Lalanne R, Spiluttini B, Bertin C, Arsac LM. (2018). Effects of heart rate variability biofeedback training in athletes exposed to stress of university examinations. PLoS One, 13(7), e0201388. PMID 30048519.
Dziembowska I, Izdebski P, Rasmus A, Brudny J, Grzelczak M, Cysewski P. (2016). Effects of heart rate variability biofeedback on EEG alpha asymmetry and anxiety symptoms in male athletes: a pilot study. Applied Psychophysiology and Biofeedback, 41(2), 141-150. PMID 26459346.
Jiménez Morgan S, Molina Mora JA. (2017). Effect of heart rate variability biofeedback on sport performance, a systematic review. Applied Psychophysiology and Biofeedback, 42(3), 235-245. PMID 28573597.
Lagos L, Vaschillo E, Vaschillo B, Lehrer P, Bates M, Pandina R. (2008). Heart rate variability biofeedback as a strategy for dealing with competitive anxiety: a case study. Biofeedback, 36(3), 109-115.
Li Q, Shi M, Steward CJ, Che K, Zhou Y. (2024). A comparison between pre-sleep heart rate variability biofeedback and electroencephalographic biofeedback training on sleep in national level athletes with sleep disturbances. Applied Psychophysiology and Biofeedback, 49(1), 115-124. PMID 37804409.
Makaracı M, Makaracı Y, Zorba E, Lautenbach F. (2024). Effects of ten biofeedback sessions on athletes' physiological, psychological, and cognitive functioning: a randomized controlled trial with international tennis players. Perceptual and Motor Skills, 131(5), 1664-1686. PMID 39149880.
Manresa-Rocamora A, Sarabia JM, Javaloyes A, Flatt AA, Moya-Ramón M. (2021). Heart rate variability-guided training for enhancing cardiac-vagal modulation, aerobic fitness, and endurance performance: a methodological systematic review with meta-analysis. International Journal of Environmental Research and Public Health, 18(19), 10299. PMID 34639599.
Merlin Q, Vacher P, Mourot L, Levillain G, Martinent G, Nicolas M. (2024). Psychophysiological effects of slow-paced breathing on adolescent swimmers' subjective performance, recovery states, and control perception. Journal of Functional Morphology and Kinesiology, 9(1), 23. PMID 38390923.
Pagaduan JC, Chen YS, Fell JW, Xuan Wu SS. (2022). A preliminary systematic review and meta-analysis on the effects of heart rate variability biofeedback on heart rate variability and respiration of athletes. Journal of Complementary and Integrative Medicine, 19(4), 817-826. PMID 34187114.
Plews DJ, Laursen PB, Stanley J, Kilding AE, Buchheit M. (2013). Training adaptation and heart rate variability in elite endurance athletes: opening the door to effective monitoring. Sports Medicine, 43(9), 773-781. PMID 23852425.
Raidl P, Wessner B, Laister S, Csapo R. (2026). No evidence for the efficacy of slow-paced breathing as a recovery strategy after sprint interval training. International Journal of Sports Physiology and Performance, 21(2), 302-311. PMID 41569822.
Rijken NH, Soer R, de Maar E, Prins H, Teeuw WB, Peuscher J, Oosterveld FG. (2016). Increasing performance of professional soccer players and elite track and field athletes with peak performance training and biofeedback: a pilot study. Applied Psychophysiology and Biofeedback, 41(4), 421-430. PMID 27761664.
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