health

Improve Heart Rate Variability (HRV)

See how Improve Heart Rate Variability (HRV) is described as a health effect.

47Practices

These are research findings, not promises. Most options have little evidence, and results differ from person to person.

What may help

What studies found for each option, best evidence first.

47 options:7 some evidence6 mixed19 not enough evidence7 not tested in people1 personal stories only7 no benefit found

What studies foundSize of effect

Ice Bath / Cold PlungepracticeSome evidence it helpsSize of effect: Large
Some human studies found a benefit. More research could change this.
5 of 6 studies found a benefit; 1 found none. Strongest study: a pooled analysis of several trials.
A pooled analysis of randomized and non-randomized human studies found a moderate increase in heart-rate variability indices. A separate review of randomized trials found improved post-exercise vagal reactivation compared with passive recovery.
Open the Ice Bath / Cold Plunge page
QigongpracticeSome evidence it helpsSize of effect: Small
Some human studies found a benefit. More research could change this.
All 6 studies with a clear result found a benefit. Strongest study: a pooled analysis of several trials.
Open the Qigong page
Tai ChipracticeSome evidence it helpsSize of effect: Small
Some human studies found a benefit. More research could change this.
All 5 studies with a clear result found a benefit. Strongest study: a pooled analysis of several trials.
Open the Tai Chi page
High-Intensity Interval Training (HIIT)practiceSome evidence it helpsSize of effect: Not known
Some human studies found a benefit. More research could change this.
5 of 6 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
In a trial of 68 people, change in SDNN favored supramaximal high-intensity training by 5.4 ms. A review also described altered HRV and increased parasympathetic activity.
Open the High-Intensity Interval Training (HIIT) page
Strength TrainingpracticeSome evidence it helpsSize of effect: Small
Some human studies found a benefit. More research could change this.
All 3 studies with a clear result found a benefit. Strongest study: a pooled analysis of several trials.
A pooled analysis whose study designs were not recorded found a small reduction in LF (ms²) among 794 people in its outcome analysis. A separate synthesis of randomized and non-randomized human studies described modest improvements in HRV and vascular adaptations in people with COPD.
Open the Strength Training page
Forest Bathing (Shinrin-yoku)practiceSome evidence it helpsSize of effect: Not known
Some human studies found a benefit. More research could change this.
13 of 17 studies found a benefit; 4 found none. Strongest study: a randomized controlled trial.
Reviews report increased parasympathetic activity and reduced sympathetic activity during forest bathing compared with urban settings. One study described in a review found the high-frequency component of heart rate variability 10% higher after a 17 min forest walk than after a city walk, with slightly lower heart rates.
Open the Forest Bathing (Shinrin-yoku) page
CardiopracticeSome evidence it helpsSize of effect: Not known
Some human studies found a benefit. More research could change this.
All 3 studies with a clear result found a benefit. Strongest study: a randomized controlled trial.
In a randomized controlled trial of 47 people, RMSSD increased in the EXT group but not the MICT group; however, the group-by-time interaction was not significant. A separate randomized controlled trial reported improved SDNN values at both the 6th and 12th weeks.
Open the Cardio page
MeditationpracticeMixed resultsSize of effect: Not known
Studies disagree: some found a benefit, others found none. Do not count on it.
8 of 11 studies found a benefit; 3 found none. Strongest study: a pooled analysis of several trials.
A review of mindfulness exposure using virtual reality described increased heart rate variability during guided virtual-reality meditation in one study. Another pooled analysis whose study designs were not recorded found a pre-to-post intervention increase compared with control among 120 people in its heart-rate-variability analysis.
Open the Meditation page

YogapracticeMixed resultsSize of effect: Medium
Studies disagree: some found a benefit, others found none. Do not count on it.
12 of 16 studies found a benefit; 4 found none. Strongest study: a pooled analysis of several trials.
A 2025 pooled analysis whose designs were not recorded found increased RMSSD among 90 people. Findings are mixed: a 2026 pooled analysis of randomized trials found an RMSSD effect in the common-effects model but not in the random-effects model among 147 people in its RMSSD analysis.
Open the Yoga page
Alternate Nostril Breathing (Nadi Shodhana)practiceMixed resultsSize of effect: Not known
Studies disagree: some found a benefit, others found none. Do not count on it.
6 of 9 studies found a benefit; 3 found none. Strongest study: a randomized controlled trial.
Open the Alternate Nostril Breathing (Nadi Shodhana) page
BreathworkpracticeMixed resultsSize of effect: Small
Studies disagree: some found a benefit, others found none. Do not count on it.
14 of 19 studies found a benefit; 5 found none. Strongest study: a randomized controlled trial.
A 2024 review reported improved high-frequency heart-rate variability in one trial and increased heart-rate variability alongside a lower breathing rate in a 60-person diaphragmatic-breathing study. Results differ across analyses: a pooled analysis of randomized trials found a heart-rate-variability effect in one statistical model, but not another.
Open the Breathwork page
Foam RollingpracticeMixed resultsSize of effect: Not known
Studies disagree: some found a benefit, others found none. Do not count on it.
3 of 4 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
Open the Foam Rolling page
Thai MassagepracticeMixed resultsSize of effect: Not known
Studies disagree: some found a benefit, others found none. Do not count on it.
2 of 3 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
A randomized trial of 48 reported a reduction in low-frequency values compared with controls. Another trial found increases in SDNN, RMS-SD, and HF in the CTTM group, but no significant between-group differences except for LF at week 2.
Open the Thai Massage page
Red Light Therapy (Photobiomodulation)practiceNot enough evidence
Too few or too small studies to know if it works.
1 of 2 studies found a benefit; 1 found none. Strongest study: a pooled analysis of several trials.
A pooled analysis of randomized trials reported improvements in several heart-rate variability parameters compared with sham. The studied population included people with type 2 diabetes.
Open the Red Light Therapy (Photobiomodulation) page
AcupuncturepracticeNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit. Strongest study: a pooled analysis of several trials.
A pooled analysis of randomized trials involving 744 people found an increase of 13.59 ms in SDNN, a heart-rate variability measure. Results varied substantially across studies.
Open the Acupuncture page
Box BreathingpracticeNot enough evidence
Too few or too small studies to know if it works.
3 of 6 studies found a benefit; 3 found none. Strongest study: a randomized controlled trial.
After maximal exertion, a randomized trial of 62 participants found structured breathwork accelerated parasympathetic reactivation, reflected in HF-HRV. A review of randomized trials also reported findings without HRV changes, so results are mixed.
Open the Box Breathing page
Hatha YogapracticeNot enough evidence
Too few or too small studies to know if it works.
4 of 7 studies found a benefit; 3 found none. Strongest study: a study that followed people over time.
A cohort study with 20 participants reported group differences in LF power, while a quasi-experimental study with 28 participants found yoga participation influenced the course of HRV across pregnancy. Findings are mixed: an RCT with 37 participants found no significant improvement in its primary HRV outcome, Log HF.
Open the Hatha Yoga page
Mindfulness MeditationpracticeNot enough evidence
Too few or too small studies to know if it works.
3 of 4 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
A trial with 127 participants found higher RMSSD in the mindfulness-based childbirth program group than in the control group at two follow-up points. A review also reported increased RMSSD across three studies involving 120 participants.
Open the Mindfulness Meditation page
PilatespracticeNot enough evidence
Too few or too small studies to know if it works.
3 of 4 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
A trial involving 60 people found an increase in rMSSD within the Pilates group. Another trial measured a decrease in the LF/HF ratio, which the authors interpreted as improved autonomic balance; it is not a symptom scale.
Open the Pilates page
Focused Attention MeditationpracticeNot enough evidence
Too few or too small studies to know if it works.
2 of 4 studies found a benefit; 2 found none. Strongest study: a randomized controlled trial.
During recovery in a 2018 trial, heart rate variability returned to baseline in the meditation, audio-book, and control groups; skin conductance returned to baseline only in the meditation group.
Open the Focused Attention Meditation page
TENS / EMS TherapypracticeNot enough evidence
Too few or too small studies to know if it works.
1 of 2 studies found a benefit; 1 found none. Strongest study: a systematic review of studies.
A review reported that a single session of low-frequency TENS reduced low-frequency heart rate variability components and increased high-frequency components, with a lower LF/HF ratio after stimulation. This finding came from an analysis of 28 people with conditions including type 2 diabetes, hypertension, or obesity.
Open the TENS / EMS Therapy page
Binaural BeatspracticeNot enough evidence
Too few or too small studies to know if it works.
1 of 3 studies found a benefit; 2 found none. Strongest study: a randomized controlled trial.
A 20-min exposure increased high-frequency power relative to placebo in one trial; the finding described this measure as a marker of parasympathetic activation. Results conflict, as another trial reported reduced high-frequency power after Binaural Beats.
Open the Binaural Beats page
Finnish SaunapracticeNot enough evidence
Too few or too small studies to know if it works.
2 of 3 studies found a benefit; 1 found none. Strongest study: a non-randomized trial.
A 2019 quasi-experimental study of 93 people found changes in time and frequency-domain HRV variables during the cooling down period after sauna bathing, which the study interpreted as indicating a dominant role for parasympathetic activity and decreased sympathetic activity.
Open the Finnish Sauna page
Yoga NidrapracticeNot enough evidence
Too few or too small studies to know if it works.
All 3 studies with a clear result found a benefit. Strongest study: a non-randomized trial.
Open the Yoga Nidra page
Loving-Kindness Meditation (Metta)practiceNot enough evidence
Too few or too small studies to know if it works.
1 of 2 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
Open the Loving-Kindness Meditation (Metta) page
SwimmingpracticeNot enough evidence
Too few or too small studies to know if it works.
All 2 studies with a clear result found a benefit. Strongest study: a systematic review of studies.
A review described a possible positive effect of swimming on vagal heart rate variability and the regulation and stability of the circulatory system.
Open the Swimming page
Hot YogapracticeNot enough evidence
Too few or too small studies to know if it works.
1 of 2 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
An RCT with 32 participants found increased heart rate variability measured by SDNN. Findings differ: an RCT with 63 participants found no significant change in the high-frequency component of heart rate variability or in other secondary outcomes between groups.
Open the Hot Yoga page
Brisk WalkingpracticeNot enough evidence
Too few or too small studies to know if it works.
All 2 studies with a clear result found a benefit. Strongest study: a randomized controlled trial.
A 2025 trial of 20 people found RMSSD increased after both exercise sessions through 60 seconds after the intervention, although RMSSD values during those periods were lower than in the control session. A 2022 pilot study of 18 people also reported a change in SDANN alongside changes in activity and other measures.
Open the Brisk Walking page
Infrared SaunapracticeNot enough evidence
Too few or too small studies to know if it works.
1 of 2 studies found a benefit; 1 found none. Strongest study: a non-randomized trial.
A 2022 quasi-experimental study involving 16 people concluded that infrared sauna following maximal exercise supported some ANS recovery.
Open the Infrared Sauna page
Pursed-Lip BreathingpracticeNot enough evidence
Too few or too small studies to know if it works.
All 2 studies with a clear result found a benefit. Strongest study: a non-randomized trial.
A 2014 quasi-experimental study in 32 people with COPD found increases in the SD1, SD2, RMSSD and LF (ms(2)) indices after Pursed-Lip Breathing.
Open the Pursed-Lip Breathing page
FastingpracticeNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit. Strongest study: a systematic review of studies.
A 2025 review reported that supervised Buchinger-type programs were associated with increases in high-frequency heart-rate variability (HF-HRV), alongside lower State-Trait Anxiety Inventory-State (STAI-S) scores and lower morning salivary cortisol.
Open the Fasting page
Cupping TherapypracticeNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit. Strongest study: a randomized controlled trial.
In a trial of 40 healthy people, the rate of LF recovery after intense exercise was higher in the cupping group than in the sham group. The finding concerns recovery of this measure after exercise.
Open the Cupping Therapy page
Anusara YogapracticeNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
The one study found a benefit.
Regular yoga may modestly improve heart-rate variability, but results can vary with the style, breathing component, and measurement method.
Open the Anusara Yoga page
DancepracticeNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
The one study found a benefit.
Dance, particularly when combined with music and social interaction, is described as potentially increasing heart rate variability, reflecting improved autonomic balance; this is an expert-knowledge claim rather than a finding from human studies.
Open the Dance page
Jump Rope TrainingpracticeNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
The one study found a benefit.
Expert guidance suggests regular aerobic exercise such as jump rope can improve HRV, indicating better autonomic balance and cardiovascular health.
Open the Jump Rope Training page
Laughter Yoga / TherapypracticeNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
The one study found a benefit.
Laughter Yoga is proposed to increase heart rate variability, described as a marker of autonomic flexibility and stress resilience.
Open the Laughter Yoga / Therapy page
Transcendental MeditationpracticeNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
The one study found a benefit.
Transcendental Meditation is described as increasing heart rate variability and parasympathetic tone, reflecting improved autonomic balance and stress resilience.
Open the Transcendental Meditation page
Vinyasa YogapracticeNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
The one study found a benefit.
Yoga has been associated with increased vagally mediated heart rate variability in small trials, but the effect of dynamic flow styles is less well characterized than that of slower styles.
Open the Vinyasa Yoga page
Latin Dance FitnesspracticeNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
The one study found a benefit.
Regular aerobic training is described as increasing heart rate variability, reflecting improved autonomic function.
Open the Latin Dance Fitness page
Grounding / EarthingpracticeOnly personal stories
Only people's own stories online. No study has tested it.
The one study found a benefit.
Grounding may improve heart rate variability as an indicator of autonomic balance; the rationale describes the evidence as limited to small trials.
Open the Grounding / Earthing page
Hot BathpracticeNo benefit found
Studies looked for a benefit and did not find one.
0 of 2 studies found a benefit; 2 found none. Strongest study: a randomized controlled trial.
A randomized trial of 10 found no group differences in heart rate variability. The studies did not support an improvement in this measure.
Open the Hot Bath page
Gratitude JournalpracticeNo benefit found
Studies looked for a benefit and did not find one.
The one study found no benefit. Strongest study: a randomized controlled trial.
A randomized trial involving 70 people with heart failure found no resting preintervention-to-postintervention group differences in heart rate variability (p values >.10).
Open the Gratitude Journal page
Wim Hof Method BreathingpracticeNo benefit found
Studies looked for a benefit and did not find one.
The one study found no benefit. Strongest study: a randomized controlled trial.
A randomized trial of 42 healthy participants found no significant time × group interactions in RMSSD, so the studies did not support an improvement in heart rate variability.
Open the Wim Hof Method Breathing page
Indoor RowingpracticeNo benefit found
Studies looked for a benefit and did not find one.
The one study found no benefit. Strongest study: a randomized controlled trial.
Studies did not support an improvement: a randomized trial in 15 people found no influence of exercise training on mean heart rate or RMSSD.
Open the Indoor Rowing page
Tabata TrainingpracticeNo benefit found
Studies looked for a benefit and did not find one.
The one study found no benefit. Strongest study: a non-randomized trial.
Studies did not support an improvement in heart rate variability: a 2025 quasi-experimental study of 18 dancers and sedentary individuals found no significant changes in the measured heart rate variability indicators.
Open the Tabata Training page
Coherent BreathingpracticeNo benefit found
Studies looked for a benefit and did not find one.
1 of 2 studies found a benefit; 1 found none.
A 15-person pilot in people with a clinical condition found no significant improvement in HRV or blood pressure after three months.
Open the Coherent Breathing page
CyclingpracticeNo benefit found
Studies looked for a benefit and did not find one.
1 of 2 studies found a benefit; 1 found none.
The available findings do not support an HRV improvement. A cohort study of 38 people reported that ApEn increases during cycling were more pronounced in females than males.
Open the Cycling page

Show all 47

Comparing practices

Ice Bath / Cold PlungeSome evidence it helpsSize of effect: Large5 trials
YogaMixed resultsSize of effect: Medium10 trials
BreathworkMixed resultsSize of effect: Small10 trials

The expert view shows every study, dose protocol and source.

What may help

Linked to improving it47 listed

Start here

Most likely to help, from the evidence we have

PracticesMeditationCertaintyMediumSourceRCT11 other sources
A review of mindfulness exposure using virtual reality described increased heart rate variability during guided virtual-reality meditation in one study. Another pooled analysis whose study designs were not recorded found a pre-to-post intervention increase compared with control among 120 people in its heart-rate-variability analysis.
Who was studied
Healthy people and patients
Study result
Across studies, reported physiological changes generally corresponded with reductions in autonomic arousal following VR-based mindfulness exposure. Kim et al reported increased HRV and reduced HR during guided VR meditation; Ng et al observed decreased skin conductance levels and increased alpha EEG
Open Meditation
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PracticesIce Bath / Cold PlungeCertaintyMediumSourceRCTLarge effect7 other sources
A pooled analysis of randomized and non-randomized human studies found a moderate increase in heart-rate variability indices. A separate review of randomized trials found improved post-exercise vagal reactivation compared with passive recovery.
How big is the effect
Large effectA big difference on average. Check how strong the evidence is.
Who was studied
Healthy people
Study result
Our results reveal a significant increase in HRV indices: RMSSD (Standardized mean difference (SMD) = 0.61, p ...
Open Ice Bath / Cold Plunge
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PracticesQigongCertaintyMediumSourceRCTSmall effect6 other sources
A 2026 meta-analysis pooling randomized and non-randomized human studies found improved SDNN with TCQ among 543 people in its analysis (g = 0.47, 95% CI: [0.22, 0.72]). A 2021 review also reported improved heart rate variability with Qigong compared with meditation, no treatment, and physical stretching.
How big is the effect
Small effectA small but noticeable difference on average.
Who was studied
Healthy people and patients
Anxiety Disorder
Breast Cancer
Chronic Fatigue Syndrome
Diabetes
Fibromyalgia
Lymphoma
+1 more
Study result
Ten studies (N = 543) provided SDNN data, and pooled analyses showed a moderate improvement with TCQ (g = 0.47, 95% CI: [0.22, 0.72]; p
Open Qigong
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PracticesTai ChiCertaintyMediumSourceRCTSmall effect5 other sources
A pooled analysis of randomized and non-randomized human studies found a small improvement in SDNN, a time-domain heart-rate variability index (g = 0.47, 95% CI: [0.22, 0.72]), among 543 people in its outcome analysis in 2026. A separate 2026 trial reported decreases in SDNN and rMSSD immediately after Tai Chi, so results differed by measurement and timing.
How big is the effect
Small effectA small but noticeable difference on average.
Who was studied
Healthy people and patients
Breast Cancer
Cerebrovascular Disease
Depression
Multiple Sclerosis
Parkinsons Disease
Tension Headache
Study result
Ten studies (N = 543) provided SDNN data, and pooled analyses showed a moderate improvement with TCQ (g = 0.47, 95% CI: [0.22, 0.72]; p…). The abstract is truncated at the p-value. SDNN is a time-domain HRV index, not an inverted instrument.
Open Tai Chi
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PracticesHigh-Intensity Interval Training (HIIT)CertaintyMediumSourceRCT6 other sources
In a trial of 68 people, change in SDNN favored supramaximal high-intensity training by 5.4 ms. A review also described altered HRV and increased parasympathetic activity.
Who was studied
Healthy people and patients
Coronary Artery Disease
Diabetes Type2
Heart Disease
Heart Failure
Hypertension
Metabolic Syndrome
+2 more
Study result
The observed improvements in ANS function, as evidenced by increased parasympathetic activity and altered HRV, align with the known benefits of aerobic exercise on CV health.
Open High-Intensity Interval Training (HIIT)
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PracticesStrength TrainingCertaintyMediumSourceRCTSmall effect3 other sources
A pooled analysis whose study designs were not recorded found a small reduction in LF (ms²) among 794 people in its outcome analysis. A separate synthesis of randomized and non-randomized human studies described modest improvements in HRV and vascular adaptations in people with COPD.
How big is the effect
Small effectA small but noticeable difference on average.
Who was studied
People with a condition
Copd
Study result
Exercise had a significant reduction effect on LF (ms²) [SMD=0.23, 95%CI (0.03, 0.42)]
Open Strength Training
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PracticesYogaCertaintyMediumSourceRCTModerate effectconflicting findings16 other sources
A 2025 pooled analysis whose designs were not recorded found increased RMSSD among 90 people. Findings are mixed: a 2026 pooled analysis of randomized trials found an RMSSD effect in the common-effects model but not in the random-effects model among 147 people in its RMSSD analysis.
How big is the effect
Moderate effectA clear difference on average.
Who was studied
Healthy people and patients
Addiction Drugs
Cancer
Copd
Coronary Artery Disease
Diabetes Type2
Elderly
+4 more
Study result
Pooled results show that post-intervention yoga was associated with significantly increased RMSSD (SMD = 35.76; 95% CI: 30.60, 40.93)
Open Yoga
→

Medium probability(6)

PracticesBreathworkCertaintyMediumSourceRCTSmall effectconflicting findings19 other sources
A 2024 review reported improved high-frequency heart-rate variability in one trial and increased heart-rate variability alongside a lower breathing rate in a 60-person diaphragmatic-breathing study. Results differ across analyses: a pooled analysis of randomized trials found a heart-rate-variability effect in one statistical model, but not another.
How big is the effect
Small effectA small but noticeable difference on average.
Who was studied
Healthy people and patients
Anxiety Generalized
Depression
Hypertension
Parkinsons Disease
Study result
One RCT found significant reduction in LF(nu) and improvement in HF(nu)
Open Breathwork
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PracticesForest Bathing (Shinrin-yoku)CertaintyMediumSourceClinical17 other sources
Reviews report increased parasympathetic activity and reduced sympathetic activity during forest bathing compared with urban settings. One study described in a review found the high-frequency component of heart rate variability 10% higher after a 17 min forest walk than after a city walk, with slightly lower heart rates.
Who was studied
Healthy people and patients
Alzheimers Disease
Anxiety Disorder
Anxiety Generalized
Cancer
Chronic Pain
Copd
+12 more
Study result
Increased parasympathetic nervous activity and suppresses sympathetic activity of forest bathing participants compared with the urban environment
Open Forest Bathing (Shinrin-yoku)
→
PracticesAlternate Nostril Breathing (Nadi Shodhana)CertaintyMediumSourceClinical9 other sources
A 2023 randomized trial of 100 participants found an increase in RMSSD, a time-domain measure of heart rate variability, of MD 7.36 ms. Another randomized trial reported increased high-frequency and decreased low-frequency components and LF/HF among people practising pranayama.
Who was studied
Healthy people and patients
Anxiety Disorder
Hypertension
Parkinsons Disease
Study result
In the time domain of heart rate variability, there was a significant increase in RMSSD (p = 0.029)
Open Alternate Nostril Breathing (Nadi Shodhana)
→
PracticesFoam RollingCertaintyMediumSourceClinical4 other sources
In a trial of 40 people, SDNN rose from 44.88±2.81 to 54.63±1.30 ms in the experimental group, compared with 45.84±3.52 to 47.52±3.29 in the control group. A separate trial of 27 people reported improved parasympathetic nervous activity and negative mood after passive foam rolling.
Who was studied
Healthy people and patients
Back Pain
Study result
SDNN increased from 44.88±2.81 to 54.63±1.30 ms in experimental group vs 45.84±3.52 to 47.52±3.29 in control; group×time interaction F=147.521, p<0.05
Open Foam Rolling
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PracticesThai MassageCertaintyMediumSourceClinical3 other sources
A randomized trial of 48 reported a reduction in low-frequency values compared with controls. Another trial found increases in SDNN, RMS-SD, and HF in the CTTM group, but no significant between-group differences except for LF at week 2.
Who was studied
Healthy people and patients
Autism Spectrum
Headache Disorder
Study result
significant reduction in low-frequency value (p=0.001) compared with the controls
Open Thai Massage
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PracticesCardioCertaintyMediumSourceClinical3 other sources
In a randomized controlled trial of 47 people, RMSSD increased in the EXT group but not the MICT group; however, the group-by-time interaction was not significant (p = .057). A separate randomized controlled trial reported improved SDNN values at both the 6th and 12th weeks.
Who was studied
Healthy people and patients
Hypertension
Study result
RMSSD (F(1, 41.23) = 16.27, p < .001, 95% CI [5.86, 16.95]) increased in the EXT group (p < .001), but not in the MICT group (p = .154). The group × time interaction was not significant (p = .057).
Open Cardio
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Low probability(28)

PracticesRed Light Therapy (Photobiomodulation)CertaintyLowSourceRCT2 other sources
A pooled analysis of randomized trials reported improvements in several heart-rate variability parameters compared with sham. The studied population included people with type 2 diabetes.
Who was studied
Healthy people and patients
Diabetes Type2
Study result
Significant between-group improvements in several HRV parameters were observed compared with sham.
Open Red Light Therapy (Photobiomodulation)
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PracticesAcupunctureCertaintyLowSourceRCT1 other source
A pooled analysis of randomized trials involving 744 people found an increase of 13.59 ms in SDNN, a heart-rate variability measure. Results varied substantially across studies (I² = 98.8%).
Who was studied
People with a condition
Study result
For SDNN, the pooled MD was 13.59 (95% CI: 4.19 to 22.98; I^2 = 98.8%, p = 0.0091)
Open Acupuncture
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PracticesBox BreathingCertaintyLowSourceClinical6 other sources
After maximal exertion, a randomized trial of 62 participants found structured breathwork accelerated parasympathetic reactivation, reflected in HF-HRV. A review of randomized trials also reported findings without HRV changes, so results are mixed.
Who was studied
Healthy people and patients
Surgery Post
Study result
Conclusions Structured breathwork following maximal exertion significantly accelerated parasympathetic reactivation as reflected by HF-HRV.
Open Box Breathing
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PracticesHatha YogaCertaintyLowSourceClinical7 other sources
A cohort study with 20 participants reported group differences in LF power, while a quasi-experimental study with 28 participants found yoga participation influenced the course of HRV across pregnancy. Findings are mixed: an RCT with 37 participants found no significant improvement in its primary HRV outcome, Log HF.
Who was studied
Healthy people and patients
Cancer
Pregnancy
Study result
Statistically significant differences were noted between the groups in ... LF (ms2) (p < 0.001) ... The increase in LF power suggested a combined influence of both sympathetic and parasympathetic activity.
Open Hatha Yoga
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PracticesMindfulness MeditationCertaintyLowSourceClinical4 other sources
A trial with 127 participants found higher RMSSD in the mindfulness-based childbirth program group than in the control group at two follow-up points. A review also reported increased RMSSD across three studies involving 120 participants.
Who was studied
People with a condition
Study result
A statistically significant Group × Time interaction was found for RMSSD (β = 0.119, p < .001). In the MBDCP, RMSSD increased from T0 to T1 (M_diff = 7.723, p < .001)... RMSSD was higher in the MBDCP compared with the control group at T1 (M_diff = 10.353, p < .01) and T2 (M_diff = 9.473, p < .01).
Open Mindfulness Meditation
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PracticesPilatesCertaintyLowSourceClinical4 other sources
A trial involving 60 people found an increase in rMSSD within the Pilates group. Another trial measured a decrease in the LF/HF ratio, which the authors interpreted as improved autonomic balance; it is not a symptom scale.
Who was studied
Healthy people and patients
Hypertension
Obesity
Study result
the MP group presented increased rMSSD (mean difference within-group = 15.7; p = 0.01)
Open Pilates
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PracticesFocused Attention MeditationCertaintyLowSourceClinical4 other sources
During recovery in a 2018 trial, heart rate variability returned to baseline in the meditation, audio-book, and control groups; skin conductance returned to baseline only in the meditation group.
Who was studied
People with a condition
Hiv Aids
Study result
During recovery, meditators' heart rate variability and skin conductance levels returned to baseline, whereas only heart rate variability returned to baseline for the audio book and control groups.
Open Focused Attention Meditation
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PracticesTENS / EMS TherapyCertaintyLowSourceClinical2 other sources
A review reported that a single session of low-frequency TENS reduced low-frequency heart rate variability components and increased high-frequency components, with a lower LF/HF ratio after stimulation. This finding came from an analysis of 28 people with conditions including type 2 diabetes, hypertension, or obesity.
Who was studied
People with a condition
Diabetes Type2
Hypertension
Obesity
Study result
a single session of Lo-TENS significantly reduced the low-frequency (0.04 to 0.15 Hz) components (LF) and increased the normalized units of high-frequency (0.15 to 0.40 Hz) components (HF) of heart rate variability (HRV)... significant decrease in the LF/HF ratio after stimulation, indicating a pote
Open TENS / EMS Therapy
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PracticesBinaural BeatsCertaintyLowSourceClinical3 other sources
A 20-min exposure increased high-frequency power relative to placebo in one trial; the finding described this measure as a marker of parasympathetic activation. Results conflict, as another trial reported reduced high-frequency power after Binaural Beats.
Who was studied
Healthy people and patients
Multiple Sclerosis
Study result
Binaural-beat exposure also decreased LF power and LF/HF ratio. ... results demonstrate that, relative to placebo, 20-min of exposure to binaural beats significantly increased HF power – a known marker of parasympathetic activation
Open Binaural Beats
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PracticesFinnish SaunaCertaintyLowSourceClinical3 other sources
A 2019 quasi-experimental study of 93 people found changes in time and frequency-domain HRV variables during the cooling down period after sauna bathing, which the study interpreted as indicating a dominant role for parasympathetic activity and decreased sympathetic activity.
Who was studied
Healthy people and patients
Study result
Time and frequency-domain HRV variables were significantly modified (p... HRV increased during the cooling down period from sauna bathing, which indicates the dominant role of parasympathetic activity and decreased sympathetic activity
Open Finnish Sauna
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PracticesYoga NidraCertaintyLowSourceClinical3 other sources
In a 2025 quasi-experimental study involving people with coronary artery disease or hypertension, the difference between groups at three months was MD 13.21 n.u. [4.8, 21.5] among 32 participants.
Who was studied
People with a condition
Coronary Artery Disease
Hypertension
Study result
At three months, the statistically significant difference (p = 0.003) between groups is supported by a confidence interval (4.80, 21.50) that does not cross zero, indicating a reliable and meaningful difference. The effect size of 0.61 further indicates a large effect, highlighting a substantial imp
Open Yoga Nidra
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PracticesLoving-Kindness Meditation (Metta)CertaintyLowSourceClinical2 other sources
In a randomized trial involving people with PTSD, HRV measured by RMSSD was higher in the COMP condition than in the NEUT condition among the ATP group (MD 1.41 ms).
Who was studied
People with a condition
Ptsd
Study result
The ATP group had a higher HRV in terms of the RMSSD, t(40) = −2.05, p = 0.047, in the COMP condition (M = 30.38) than in the NEUT condition (M = 28.97).
Open Loving-Kindness Meditation (Metta)
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PracticesSwimmingCertaintyLowSourceClinical2 other sources
A review described a possible positive effect of swimming on vagal heart rate variability and the regulation and stability of the circulatory system.
Study result
Swimming seems to positively affect the regulation and stability of the circulatory system, the vagal heart rate variability, and the index of vagosympathetic interaction
Open Swimming
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PracticesHot YogaCertaintyLowSourceClinical2 other sources
An RCT with 32 participants found increased heart rate variability measured by SDNN. Findings differ: an RCT with 63 participants found no significant change in the high-frequency component of heart rate variability or in other secondary outcomes between groups.
Who was studied
Healthy people and patients
Study result
increased heart rate variability (SDNN): F(1, 29)=5.12, p=.013, η_p^2=.150
Open Hot Yoga
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PracticesBrisk WalkingCertaintyLowSourceClinical2 other sources
A 2025 trial of 20 people found RMSSD increased after both exercise sessions through 60 seconds after the intervention, although RMSSD values during those periods were lower than in the control session. A 2022 pilot study of 18 people also reported a change in SDANN alongside changes in activity and other measures.
Who was studied
People with a condition
Heart Failure
Peripheral Artery Disease
Study result
The RMSSD (Figure 3B) increased significantly after both exercise sessions until 60 seconds after the intervention (p<0.05). The RMSSD values during these periods were lower in the exercise sessions than in the control session (p=0.014).
Open Brisk Walking
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PracticesInfrared SaunaCertaintyLowSourceClinical2 other sources
A 2022 quasi-experimental study involving 16 people concluded that infrared sauna following maximal exercise supported some ANS recovery.
Who was studied
Healthy people and patients
Study result
Conclusions: These findings indicate that FIRS following maximal exercise did support some ANS recovery...
Open Infrared Sauna
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PracticesPursed-Lip BreathingCertaintyLowSourceClinical2 other sources
A 2014 quasi-experimental study in 32 people with COPD found increases in the SD1, SD2, RMSSD and LF (ms(2)) indices after Pursed-Lip Breathing.
Who was studied
Healthy people and patients
Study result
PLB promoted significant increases in the SD1, SD2, RMSSD and LF (ms(2)) indices ... in the COPD group.
Open Pursed-Lip Breathing
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PracticesFastingCertaintyLowSourceClinical1 other source
A 2025 review reported that supervised Buchinger-type programs were associated with increases in high-frequency heart-rate variability (HF-HRV), alongside lower State-Trait Anxiety Inventory-State (STAI-S) scores and lower morning salivary cortisol.
Study result
supervised Buchinger-type programs consistently reported reductions in State-Trait Anxiety Inventory-State (STAI-S) scores, lower morning salivary cortisol, and increases in high-frequency heart-rate variability (HF-HRV)
Open Fasting
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PracticesCupping TherapyCertaintyLowSourceClinical1 other source
In a trial of 40 healthy people, the rate of LF recovery after intense exercise was higher in the cupping group than in the sham group. The finding concerns recovery of this measure after exercise.
Who was studied
Healthy people
Study result
the rate of LF recovery after intense exercise was significantly higher in the cupping group than in the sham group (P = .013)
Open Cupping Therapy
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PracticesGrounding / EarthingCertaintyLowSourceAnecdotal2 other sources
Grounding may improve heart rate variability as an indicator of autonomic balance; the rationale describes the evidence as limited to small trials.
Study result
Grounding may improve heart rate variability, indicating enhanced autonomic balance, though evidence is limited to small trials.
Open Grounding / Earthing
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PracticesCoherent BreathingCertaintyLowSourceTheoretical3 other sources
A 15-person pilot in people with a clinical condition found no significant improvement in HRV or blood pressure after three months.
Who was studied
People with a condition
Open Coherent Breathing
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PracticesAnusara YogaCertaintyLowSourceTheoretical1 other source
Regular yoga may modestly improve heart-rate variability, but results can vary with the style, breathing component, and measurement method.
Study result
Regular yoga may produce modest improvements in heart-rate variability, although results vary by style, breathing component, and measurement method.
Open Anusara Yoga
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PracticesDanceCertaintyLowSourceTheoretical1 other source
Dance, particularly when combined with music and social interaction, is described as potentially increasing heart rate variability, reflecting improved autonomic balance; this is an expert-knowledge claim rather than a finding from human studies.
Study result
Dance, particularly when combined with music and social interaction, may increase heart rate variability, reflecting improved autonomic balance.
Open Dance
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PracticesJump Rope TrainingCertaintyLowSourceTheoretical1 other source
Expert guidance suggests regular aerobic exercise such as jump rope can improve HRV, indicating better autonomic balance and cardiovascular health.
Study result
Regular aerobic exercise like jump rope improves heart rate variability (HRV), indicating better autonomic balance and cardiovascular health.
Open Jump Rope Training
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PracticesLaughter Yoga / TherapyCertaintyLowSourceTheoretical1 other source
Laughter Yoga is proposed to increase heart rate variability, described as a marker of autonomic flexibility and stress resilience.
Study result
Laughter Yoga increases heart rate variability, a marker of autonomic flexibility and stress resilience.
Open Laughter Yoga / Therapy
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PracticesTranscendental MeditationCertaintyLowSourceTheoretical1 other source
Transcendental Meditation is described as increasing heart rate variability and parasympathetic tone, reflecting improved autonomic balance and stress resilience.
Study result
TM increases heart rate variability and parasympathetic tone, reflecting improved autonomic balance and stress resilience.
Open Transcendental Meditation
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PracticesVinyasa YogaCertaintyLowSourceTheoretical1 other source
Yoga has been associated with increased vagally mediated heart rate variability in small trials, but the effect of dynamic flow styles is less well characterized than that of slower styles.
Study result
Yoga has been associated with increased vagally mediated heart rate variability in small trials; effects with dynamic flow styles are less well characterized than with slower styles.
Open Vinyasa Yoga
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PracticesLatin Dance FitnessCertaintyLowSourceTheoretical1 other source
Regular aerobic training is described as increasing heart rate variability, reflecting improved autonomic function.
Study result
Regular aerobic training increases heart rate variability, reflecting improved autonomic function.
Open Latin Dance Fitness
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Very low probability(6)

PracticesHot BathCertaintyVery lowSourceClinical2 other sources
A randomized trial of 10 found no group differences in heart rate variability. The studies did not support an improvement in this measure.
Who was studied
Healthy people
Open Hot Bath
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PracticesGratitude JournalCertaintyVery lowSourceClinical1 other source
A randomized trial involving 70 people with heart failure found no resting preintervention-to-postintervention group differences in heart rate variability (p values > .10).
Who was studied
People with a condition
Heart Failure
Open Gratitude Journal
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PracticesWim Hof Method BreathingCertaintyVery lowSourceClinical1 other source
A randomized trial of 42 healthy participants found no significant time × group interactions in RMSSD (p = 0.820), so the studies did not support an improvement in heart rate variability.
Who was studied
Healthy people
Open Wim Hof Method Breathing
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PracticesIndoor RowingCertaintyVery lowSourceClinical1 other source
Studies did not support an improvement: a randomized trial in 15 people found no influence of exercise training on mean heart rate or RMSSD.
Who was studied
People with a condition
Open Indoor Rowing
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PracticesTabata TrainingCertaintyVery lowSourceClinical1 other source
Studies did not support an improvement in heart rate variability: a 2025 quasi-experimental study of 18 dancers and sedentary individuals found no significant changes in the measured heart rate variability indicators.
Who was studied
Healthy people
Open Tabata Training
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PracticesCyclingCertaintyVery lowSourceTheoretical2 other sources
The available findings do not support an HRV improvement. A cohort study of 38 people reported that ApEn increases during cycling were more pronounced in females than males.
Who was studied
Healthy people
Open Cycling
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Practices compared

Practices with at least one trial of their own for this goal. Ranked by how sure the evidence is, then effect size.Top 10 of 31

Practice	How sure	Effect size	Own trials	What worked in trials
Ice Bath / Cold Plunge	CertaintyMediumSourceRCT	Large effect	5 trials or pooled analyses	14–15 min
Yoga	CertaintyMediumSourceRCT	Moderate effect	10 trials or pooled analyses	40–45 min · 2–3×/week · 2–12 weeks
Breathwork	CertaintyMediumSourceRCT	Small effect	10 trials or pooled analyses	5–15 min · 7–10.5×/week · 6–12 weeks
Qigong	CertaintyMediumSourceRCT	Small effect	5 trials or pooled analyses	60 min · 2–3.5×/week · 8–12 weeks
Strength Training	CertaintyMediumSourceRCT	Small effect	3 trials or pooled analyses	3–3.2×/week · 4–7 weeks
Tai Chi	CertaintyMediumSourceRCT	Small effect	3 trials or pooled analyses	20–33 min
Forest Bathing (Shinrin-yoku)	CertaintyMediumSourceClinical		8 trials or pooled analyses
Meditation	CertaintyMediumSourceRCT		6 trials or pooled analyses	10–12 min · 1–7×/week · 1.4–4 weeks
Alternate Nostril Breathing (Nadi Shodhana)	CertaintyMediumSourceClinical		5 trials or pooled analyses	12–15 min · 7–10.5×/week · 6–9 weeks
High-Intensity Interval Training (HIIT)	CertaintyMediumSourceRCT		4 trials or pooled analyses	30–36 min · 2–3×/week · 8–12 weeks

What worked in trials: From the smallest to the typical amount in the trials that found this benefit. Not the most anyone did, not a target and not a limit.

How to read the evidence

Evidence tier — overall strength of the evidence for the whole compound

StrongWell established — backed by strong, consistent human research.
ModerateSome genuine support, but mostly from small or lower-quality studies. Promising, not proven.
PreliminaryEarly-stage evidence — a promising hypothesis, not an established effect yet.
LimitedVery limited evidence — treat this as a hypothesis, not proof.
InsufficientNot enough good evidence to draw conclusions yet.

Certainty — how sure we can be that the effect is real

Very highVery sure — strong, consistent evidence
HighFairly sure — consistent evidence from good studies
MediumModerately sure — new studies could change this
LowNot sure — little or mixed evidence
Very lowVery unsure — almost no usable evidence

Source — where the data comes from

Meta-analysisPooled analysis of many trials — the strongest evidence
RCTRandomized controlled trial — a strong human study design
ClinicalA human clinical study
Reference knowledgeFrom general health-science or pharmacology references, not a study of this exact claim
Animal researchStudied in animals, not humans
Community reportsAggregated user reports — anecdotal signal, not evidence
TheoreticalMechanism-based reasoning, not yet tested

Study grade — quality of each underlying study (A best, D weakest)

AHigh-quality — strong, consistent human trials
BGood — solid evidence with some limitations
CModerate — limited, small, or mixed-quality studies
DWeak — preliminary, indirect, or animal-only

Confidence — how strongly the sources back a finding

A 0–100 score from study quality and agreement

Most supplement evidence is graded C–D. Read it as preliminary signal, not proof.

Full write-up

What is it

Improving heart rate variability (HRV) refers to a favorable change in the variation of timing between normal heartbeats. It is not simply a faster or slower heart rate; it concerns the pattern and variability of intervals from one beat to the next. HRV may be assessed using measures such as SDNN, low-frequency components, the HRV index, or the LF/HF ratio.

How interventions help

Interventions linked with improved HRV span movement practices, controlled breathing, electrical stimulation, and supplements, but they differ in how quickly they were assessed and what HRV measure changed. Yoga-related approaches and Tai Chi were evaluated as ongoing practices, while swimming was associated with changes in circulatory regulation, vagal HRV, and vagosympathetic interaction. Box Breathing represents a more immediate approach: controlled, rhythmic breathing at approximately 6 breaths/min reliably increases HRV, a marker of parasympathetic tone.

Some interventions were assessed after a single session or acute dose. TENS / EMS Therapy changed the balance of low- and high-frequency HRV components after one session, while Lavender Extract, Valerian Root, Beetroot Extract, Creatine, Saffron Extract, and Magnesium were also examined for relatively immediate responses. Other supplement protocols lasted several weeks, including studies of Magnesium and Ashwagandha, while Creatine was assessed over a shorter multi-day period. These designs suggest that some findings concern short-term changes rather than effects that are known to persist after stopping.

The outcome is not measured identically across interventions: findings include changes in RMSSD, NN50, pNN50%, SDNN, frequency components, HRV index, or related ratios. Results from yoga studies also indicate that style, breathing component, and measurement method can affect the observed result. Applicability varies because studies included healthy participants, people with clinical conditions, and mixed or unspecified groups; a finding in one population may not transfer directly to another.

Choosing guidance

When choosing among these options, first consider whether you want a movement practice, a breathing or relaxation approach, a device-based intervention, or a supplement. Movement-based options such as Yoga, Tai Chi, and Swimming may suit people looking for an activity-based approach, while breathing and meditation practices may suit those seeking a low-equipment option. Supplements may be more relevant when a defined intake and study schedule can be followed, but their protocols are not interchangeable.

Timing differs considerably. Some options were assessed immediately after a session or acute exposure, while others were studied with repeated use over several weeks. This means a result observed soon after an intervention should not automatically be compared with one measured after a longer course. Check whether the study pattern resembles the way the option would actually be used, including how much was taken and how long it was continued.

The human evidence is also uneven. Several movement practices and interventions have been examined directly in people, whereas some options rely mainly on theoretical explanations, reviews, anecdotal reports, or evidence that is not directly from humans. Those categories provide different levels of practical applicability and should not be treated as equivalent.

Comparisons can also be affected by the type of HRV measurement, the breathing component, the activity style, and when the measurement was taken. Where results vary across approaches, this may reflect differences in protocols rather than a simple ranking. For a cautious choice, favor an option whose study population, timing, and method most closely match the situation of interest.