What actually raises HRV — and what does not

First: the ceiling you cannot move

A large share of your resting HRV is set by things you do not control. Age is the biggest: population RMSSD falls from roughly 60 milliseconds in the early twenties to the low twenties by the seventies. Genetics, body size, resting heart rate and cardiovascular structure account for much of the rest.

What this means practically: you are not going to turn a 25 ms baseline into a 90 ms baseline. What you can do is stop suppressing your own ceiling, and recover the — often substantial — gap between where you sit and where you could sit. For most people that gap is worth more than any exotic intervention.

Judge everything below against your own rolling baseline, never against someone else's number.

1. Remove alcohol

The largest, fastest, most reliable change available to most people. Alcohol suppresses parasympathetic activity for hours, hits hardest in the first half of the night, and does so at quantities most people consider ordinary. Two drinks is enough to flatten a night.

If you drink most evenings and your overnight HRV is chronically low, this is not one factor among many — it is very likely the dominant one. Four alcohol-free nights a week for a fortnight will show you the size of the effect in your own data more convincingly than any study will.

2. Build an aerobic base

Regular aerobic exercise is the intervention with the best evidence for raising baseline HRV rather than briefly nudging it. Meta-analyses of training studies find consistent increases in vagally mediated HRV in previously untrained people, and endurance athletes sit far above population norms for their age.

The training that does this is mostly easy: sustained work at conversational intensity, three to five times a week. Adaptations take months, not days. Chasing intensity is counterproductive here — high-intensity work acutely lowers HRV for a day or two, and a programme made entirely of hard sessions produces a chronically suppressed reading.

3. Fix sleep regularity

Sleep is when most autonomic recovery happens, and timing consistency appears to matter more than total hours. A fixed wake time stabilises the circadian signal the whole system runs on. See the sleep and recovery guide for the detail.

4. Daily slow breathing

Ten minutes a day at around six breaths per minute produces a large acute rise in HRV during the session and, over four to ten weeks, measurable reductions in perceived stress and anxiety. Effects on resting HRV outside sessions are real but more modest than the acute effect suggests.

The honest framing: breathwork improves how well you regulate and how quickly you recover from a spike. Aerobic training is what moves the ceiling. Do both; they are not substitutes. The protocol is here.

5. Manage training load

Persistently suppressed HRV in someone who trains regularly is usually under-recovery rather than under-training. The standard fix is unglamorous: keep at least one genuinely easy day per week, keep the majority of weekly volume at low intensity, and treat a week-long downward drift in your rolling average as a prompt to back off rather than push through.

Athletes who use HRV well use the seven-day average, not the daily value, and they use it to decide whether today is hard or easy — not whether to train at all.

6. Change the psychological load

The lowest-tech item and often the largest. Chronic psychological stress suppresses vagal tone through the same pathways as everything above. If your PSS-10 score is in the high band, no amount of zone-2 running will fully compensate for the input.

What helps: reducing genuinely uncontrollable demands where possible, restoring agency where it exists, treating rumination directly, and using support. Cognitive behavioural approaches and structured stress-management programmes both show consistent reductions in perceived stress in randomised trials.

Plausible but smaller

• Sauna and heat exposure. Regular use is associated with cardiovascular benefit and acutely raises post-session parasympathetic activity. Reasonable, not transformative.
• Cold exposure. Produces a striking acute vagal response during and after immersion. Whether this translates into higher baseline HRV is not well established, and doing it late in the evening can disrupt sleep.
• Omega-3. Some trials show small increases in HRV, particularly at higher doses and in people with low baseline intake. Small effect, decent safety profile.
• Weight loss where relevant. Reduced adiposity is associated with improved autonomic function, likely through several mechanisms at once.
• Meditation. Consistent benefits for perceived stress; effects on HRV specifically are inconsistent outside of practices that involve slow breathing.

Things that do very little

• Chasing the daily number. Day-to-day variation is dominated by noise. Reacting to single readings creates anxiety, which — with genuine irony — lowers HRV.
• Switching devices to get a better number. Different devices and algorithms are not comparable. A new number is a new dataset, not an improvement.
• Most supplements marketed for HRV. Very few have controlled trials with HRV as an endpoint, and those that do tend to report effects smaller than measurement noise.
• Breathing apps used occasionally. The adaptation comes from daily repetition over weeks. Twice a month does nothing.

How to know if it worked

Change one thing at a time and give it four to six weeks. Compare your seven-day rolling average to your average over the previous two months, not to yesterday, and measure under identical conditions — same time, same posture, before caffeine.

Then check the psychological side too. Retake the PSS-10 at the start and at the end of the block: it is often more sensitive to a real change in load than a morning HRV reading, and when the two agree you can be reasonably confident something actually moved.