Myth or fact

A long breath hold means you're fit

Short answerNo

By GyroscopeUpdated November 14, 20265 sources

No. When researchers timed the comfortable breath hold of 49 elite speedskaters, the score had no link to their sprint test, their endurance test or their VO2 max. A breath hold tells you how early your urge to breathe kicks in. It’s a comfort number to track against yourself, and it can’t stand in for a fitness test.

Why it seems true

Fit people breathe easier, so it seems natural that they’d hold their breath longer too. Divers and swimmers are famous for it. The Body Oxygen Level Test, or BOLT, popularized by Patrick McKeown and his breathing method, the Oxygen Advantage, puts a number on it. Its supporters say the score reflects how sensitive your body is to carbon dioxide and gives feedback on exercise tolerance. By July 2024, a Google search for it turned up around 205 million websites.

Gyroscope uses the BOLT test too, as a breath benchmark. But a comfortable hold measures when your alarm goes off, and your fitness is the size of your engine. The alarm isn’t wired to the engine.

What the speedskater study found

In 2023, researchers at Poland’s Institute of Sport tested 49 speedskaters from the elite and development national teams of three countries. All of them had at least four years of competitive training. The women had an average VO2 max of 49.5 and the men 59.5 mL per kg per minute, which is very fit.

Each skater sat quietly for 15 minutes, then did the BOLT test exactly as the Oxygen Advantage method describes it: a few normal breaths through the nose, a normal breath out, a nose clip on, and a hold until the first definite urge to breathe. Later the same day they did an all-out sprint test on a bike, and a full exercise test to exhaustion that measured their oxygen use. The team running the fitness tests didn’t know anyone’s BOLT score.

The BOLT scores didn’t line up with any of it. Peak power, total work, how fast power faded, VO2 max and time to exhaustion all showed no meaningful link, with correlations from −0.17 to 0.01, about as close to zero as you get. Age, body size and years of training didn’t explain the scores either. The authors’ advice was to interpret BOLT for exercise performance in highly trained people “with a great degree of caution.”

What a breath hold depends on

A 2006 review of breath holding by the physiologist Parkes found the length of a hold is easy to time but varies a lot. It’s stretched by starting with big lungs, by breathing extra oxygen first and by low carbon dioxide, and it’s shortened by the opposite, and by working harder. Even the moment you give up has no single cause. Blood gases and lung size play a part, and so, possibly, do signals from the diaphragm.

That’s why the BOLT protocol is so strict. A deeper starting breath, a forceful breath out, breathing hard beforehand, recent exercise or pushing past the first urge each turn it into a different test, as Gyroscope’s benchmark page warns. The page calls it a comfort measure, and your score is only comparable with your own.

The coaching bands

These are practical bands from breathwork coaching. They haven’t been validated as clinical cutoffs, and they shouldn’t be used to judge anything about your lungs or your mental health. Use them to see where you stand and whether your number is drifting over months. What’s a good BOLT score?

Why training long holds is a bad idea

A comfortable hold stops at the first urge. A maximum hold pushes past it, and that’s a different and riskier thing, especially if you breathe hard first. Low carbon dioxide delays the urge to breathe while oxygen keeps falling. In freedivers, blackout is often assumed to come when blood oxygen gets near 50 percent, and a 2026 Swedish case report caught a diver losing consciousness at 51 percent. The American Red Cross, the YMCA and USA Swimming call this hypoxic blackout, and it can happen in any water at any depth.

Never practice breath holds in a pool, the ocean or the bath, and never after fast breathing. A longer hold won’t make you fitter, and the speedskaters show it won’t even tell you whether you are.

How to do the test

1. Sit upright somewhere safe and quiet, on dry land. Breathe normally through your nose for a few minutes. No deep breaths beforehand.
2. Take one normal breath in and one normal breath out through your nose. Start the timer as the breath out ends, and pinch your nose if it helps.
3. Stop at the first clear urge to breathe or swallow. Don’t push through it.
4. Breathe normally again and note the seconds. Do it the same way, at about the same time of day, once a month.

The breath hold test times it for you and shows where your number falls on the coaching bands.