Higher HRV Isn't Always Better. The Number Lies More Than You Think.

There's a quiet, almost universal belief among people who wear something on their wrist: that the goal of training, sleeping, and eating well is to make their HRV number go up.

It's a clean story. Bigger number, healthier body, better life. The trackers reinforce it — green arrows, climbing trendlines, weekly summaries that congratulate you when the chart slopes the right way.

It's also wrong in the specific way that careful misreadings tend to be wrong. Not because HRV is fake, but because the metric isn't actually the thing you think it is.

Marco Altini, who built HRV4Training and has spent the better part of a decade publishing on this, puts it bluntly in his Substack: HRV is one of the most talked-about metrics in performance, and one of the most misunderstood. The "higher is better" instinct is the first place that misreading shows up.

What HRV Actually Measures

The textbook line is that HRV reflects autonomic nervous system activity. That's true and almost useless on its own, because most people read "autonomic nervous system" as "how recovered I am" and stop there.

Closer to right: HRV is a real-time-ish read on the balance between your parasympathetic ("rest, digest, recover") and sympathetic ("alert, push, defend") branches. Higher variability between heartbeats usually means parasympathetic input is winning. Lower variability usually means sympathetic input is winning.

That balance correlates with recovery. It's not the same thing.

The autonomic system is also doing other jobs at the same time — controlling digestion, regulating blood pressure, responding to a hot room or a cold drink. None of that is "your training is going well." All of it shows up in the number.

So when Altini and the rest of the serious HRV literature say things like "HRV is not a wellness score," they mean it almost literally. It's a physiological dial, not a verdict.

Where "Higher Is Always Better" Breaks

Here are the cases where chasing a bigger HRV number leads you straight off a cliff.

Parasympathetic dominance from accumulated load. When the body has been pushed hard for weeks, the autonomic system can flip into a kind of compensatory shutdown. Sympathetic tone collapses, parasympathetic takes over by default, and HRV jumps. You'd see a chart go green and feel like death. This is documented in the endurance literature as one signature of late-stage overreaching, and it's the cleanest counter-example to the "high = good" instinct.

The morning after a bender. Some people, depending on body, dose, and timing, will actually post a higher-than-normal HRV the morning after heavy alcohol. The body is rebounding into deep parasympathetic activity to compensate for the previous night's sympathetic spike. The number looks beautiful. You feel like a wet rag. Both are accurate.

Brewing illness. In the 24 to 48 hours before symptoms hit, HRV can move in either direction. Plenty of people see an unusually high reading the day before a cold puts them flat. The immune system is mobilizing, the autonomic system is doing whatever balance-keeping work it can, and the wrist tracker is left holding a number it can't interpret.

Long, slow under-eating. People who chronically eat below their needs — cutting too aggressively, training a lot, drinking lots of coffee — often see HRV drift up, not down. The body is conserving. It's not in a sympathetic emergency, because there's nothing to emerge from. It's coasting on low fuel and the variability looks fine. Performance falls anyway.

In all four cases, the chart is telling the truth about what's happening in the autonomic system. It's the human reading it who's filling in a story that isn't there.

The Cross-Person Comparison Trap

A few weeks ago a friend texted me a screenshot of his HRV — 92 ms, with a smug little crown emoji — and asked what mine was. Mine was somewhere around 55. The implied question was who's healthier.

The honest answer is: the question is meaningless.

Resting HRV varies wildly between people based on age, sex, body size, breathing patterns at the moment of measurement, the device's measurement window, the algorithm it uses, and a half dozen other things that have nothing to do with fitness. A young, lean, well-trained 25-year-old can post 110 ms and feel terrible. A 45-year-old with a different physiology can run on 45 ms and crush a marathon training block. The two numbers are not on the same axis.

Altini's been hammering this point for years and it still hasn't landed in the consumer apps, because "compare yourself to other people" is a stickier feature than "compare yourself to yourself last month." The first one is engaging. The second one is correct.

If you're going to look at one HRV number ever, look at the gap between today and your own rolling 30-to-60-day average. That's the only frame where the metric tells you anything actionable.

What to Do When HRV Is High

This part should feel obvious by the time you get here. The answer is: usually, nothing.

If your HRV is sitting at the top of your normal range and everything else is good — sleep is fine, lifts are moving, life isn't on fire — then you're well-recovered and you can train normally. There's no medal for pushing harder because the chart looks pretty. The number is not asking anything of you.

If HRV is unusually high and you feel beat up, that's the case to slow down for a beat and check inputs. Ask yourself: have I been under-fueling? Am I starting to crash from a long training block? Am I about to come down with something? The high reading is information, but the action isn't "celebrate." It's "investigate."

The mindset shift is from chasing the number to interpreting it against context. HRV alone says very little. HRV plus your sleep last night, plus your subjective feel, plus the load you've been running, plus what your work week looked like — that composite is a real read.

A wrist screen showing a single number with a green arrow is engagement design. It's not a coaching system.

The Useful Read: Variance Around Your Own Norm

Here's the version of HRV monitoring that actually changes anything.

You record it consistently. Same time of day, same conditions, same device. Doesn't matter if it's morning on waking, overnight average, or a 60-second standing measurement — what matters is consistency. After about a month you have a personal range.

Then you stop looking at the daily number. You look at:

• How often this week was inside your normal range?
• Are the misses clustered (three days in a row) or scattered (Tuesday and Friday)?
• When the misses happened, what else was going on?

That's the read. It's slower, it's less satisfying, and it's the one that gives you a real signal instead of noise.

Most consumer apps lead with today's score because today's score is what gets you to open the app. The trend is buried two taps deep. That's a UX choice that shapes how people relate to their own bodies, and not in a flattering direction. People end up emotionally tracking a number that has a 20% day-to-day error bar, getting worried about readings that mean nothing, and missing the actual signal because it doesn't show up in a single morning.

Why I Don't Make You Look at Your HRV

This is where Dorsi sits in opposition to a lot of the wearable industry. I read your HRV. I look at the trend, against your own baseline, in context with your sleep and your recent sessions. Then I bake the answer into today's plan and don't make you look at the number.

You don't open the app to see whether your HRV says train or rest. The decision is already made by the time you walk into the gym. If today is a full-intensity day, the session reflects that. If your nervous system is asking for a pullback, the working sets are lighter and you don't have to know why.

The point of physiological data is not to give you a daily dashboard to interpret. It's to make the call so you don't have to. That is what "Just show up" means in practice — not motivational copy, but a real division of labor between you and the system.

You bring the consistency. I read the watch.

The Compressed Version

If you only remember a few things from this:

• HRV reflects autonomic balance, not how recovered you are. Recovery is downstream.
• Higher than your normal range can mean overreaching, illness, alcohol rebound, or under-fueling. Investigate, don't celebrate.
• Cross-person comparison is theatre. Your own 30-day baseline is the only frame that means anything.
• Daily reads are noise. Multi-day trends are signal.
• The best use of HRV is one you don't have to look at — when it's quietly shaping today's session in the background.

Chase the inputs — sleep, food, stress, training load, real life — and HRV follows on its own clock. Chase the number directly and you'll spend a year optimizing a chart while the actual work it's pointing at goes undone.