The researchThe science behind every breath
Every result on this page comes from a peer reviewed study, and every study links straight to the original paper.
No hype. Just the outcomes coaches care about: more repeated sprints, less fade, faster recovery and more output from every breath.
This isn't wellness. This is competitive performance.
The research
Rugby study: 64% more repeated sprints
Highly trained rugby players. 21 players, two groups, seven sessions over four weeks. Same sprint training. The only difference was how they breathed.
Sprints before task failure
Repeated sprint ability test. More sprints is better.
What they did
The protocol
- 01Repeated 40 m sprint training
- 02Seven sessions across four weeks
- 03One group held their breath after exhaling during each sprint. The other breathed normally.
- 04Tested how many sprints each player could complete before their speed dropped off
Maximum velocity did not change in either group. The gain was in the ability to repeat.
Breath hold sprint training won.Players went from 9.1 to 14.9 sprints before task failure. The normal breathing group went from 9.8 to 10.4, a change that was not statistically significant.
Source: Fornasier Santos, Millet and Woorons (2018). Repeated sprint training in hypoxia induced by voluntary hypoventilation improves running repeated sprint ability in rugby players. European Journal of Sport Science, 18(4), 504 to 512. This study compares breath hold sprint training after exhaling against normal breathing. It does not compare nasal and mouth breathing.
The research
Team sport study: 357 m further
20 well trained team sport athletes. Two groups, six sessions over three weeks. They trained on a bike and were tested running. The only difference was how they breathed.
Yo Yo test distance
Run, recover, go again. Further is better.
What they did
The protocol
- 01Six high intensity bike sprint sessions across three weeks
- 02One group held their breath after exhaling during each sprint. The other breathed normally.
- 03Both groups ran the Yo Yo intermittent recovery test, a running test of work, recover and repeat
The normal breathing group did not improve. The breath hold group ran 357 m further.
Trained on a bike. Better on the field.The breath hold group went from 1,111 m to 1,468 m in the Yo Yo test, a 32% improvement. The normal breathing group showed no change. Simple meaning: they could work, recover and go again for longer.
Source: Woorons et al. (2020). Transferable benefits of cycle hypoventilation training for run based performance in team sport athletes. International Journal of Sports Physiology and Performance, 15(8), 1103 to 1108. This study compares breath hold sprint training after exhaling against normal breathing. It does not compare nasal and mouth breathing.
The research
Basketball study: 24.5% less fade
17 basketball players. Two groups, eight sessions over four weeks. Same repeated sprint training. The only difference was how they breathed.
Less slowdown across sprints
Reduction in sprint drop off. Bigger is better.
What they did
The protocol
- 01Eight repeated sprint sessions across four weeks, straight line and change of direction
- 02One group breathed out, then held their breath at the bottom of the exhale during each sprint, not at the top of the inhale. The other breathed normally.
- 03Tested with 12 sprints of 30 m and 25 seconds rest, measuring how much players slowed down
Fastest single sprint did not change. The gain was in holding speed as fatigue built.
They held their speed as fatigue built.Holding the breath at the bottom of the exhale cut sprint drop off by 24.5%, compared with 5.9% for normal breathing. Simple meaning: when the legs started to go, the breath hold players slowed down far less.
Source: Lapointe et al. (2020). Impact of hypoventilation training on muscle oxygenation, myoelectrical changes, systemic [K+], and repeated sprint ability in basketball players. Frontiers in Sports and Active Living, 2, 29. This study compares breath hold sprint training after exhaling against normal breathing. It does not compare nasal and mouth breathing.
The research
Female football study: 17% more sprints
24 female football players. Three groups of eight, twelve sessions over six weeks. Same 30 m sprint training. The only difference was how they breathed.
More sprints before exhaustion
Improvement in repeated sprints. Bigger is better.
What they did
The protocol
- 01Twelve sessions of repeated 30 m sprints across six weeks
- 02One group held their breath after breathing out, one after breathing in, and one breathed normally
- 03Tested how many all out 30 m sprints each player could repeat
Holding after breathing out was the only method that also lifted sprint speed and reduced fade.
Breathe out, then hold. That won.Players went from 19.3 to 22.6 sprints, a 17% gain. Holding after breathing in added 6%. Normal breathing barely moved, from 19.4 to 19.5, a change that was not statistically significant.
Source: Ait Ali Braham et al. (2024). Effects of a 6 week repeated sprint training with voluntary hypoventilation at low and high lung volume on repeated sprint ability in female soccer players. International Journal of Sports Physiology and Performance, 19(5), 463 to 470. This study compares breath hold methods against normal breathing. It does not compare nasal and mouth breathing.
The research
Nasal breathing study: 22% less air
10 recreational runners trained nose only breathing for six months. Then they ran a maximal test twice, once through the mouth and once through the nose.
Air breathed at max effort
Litres per minute. Less air for the same work.
What they found
At maximal effort
- 01Maximal oxygen uptake was the same through the nose as through the mouth
- 02Slower breathing through the nose: 39 breaths a minute versus 49 through the mouth
- 03More oxygen taken from every litre of air breathed through the nose
A small pilot study of 10 runners who were already adapted to nasal breathing.
Same engine. Less air.At maximal effort the runners moved 90.5 litres of air a minute through the nose versus 117.8 through the mouth, with no loss in maximal oxygen uptake. Simple meaning: the nose made every breath work harder.
Source: Dallam et al. (2018). Effect of nasal versus oral breathing on VO2max and physiological economy in recreational runners following an extended period spent using nasally restricted breathing. International Journal of Kinesiology and Sports Science, 6(2), 22 to 29. Pilot study, 10 participants.
The research
Cycling study: 3.6x the power gain
18 well trained cyclists. Two groups, six sessions over three weeks. Same repeated sprint training. The only difference was how they breathed.
Average repeated sprint power
Group average in watts. Higher is better.
Same training. Breath hold group gained 65 W. Normal breathing gained 18 W.
What they did
The protocol
- 01Six repeated sprint sessions on the bike across three weeks
- 02One group breathed out, then held their breath at the bottom of the exhale during each sprint, not at the top of the inhale. The other breathed normally.
- 03Tested with 10 all out 6 second sprints and a 30 second Wingate test
Wingate power also rose from 723 W to 768 W in the breath hold group. The normal breathing group barely moved, from 710 W to 713 W.
More usable power when it hurts.Same sessions, same sprints. The breath hold group gained 65 W of average repeated sprint power, 846 W to 911 W. The normal breathing group gained 18 W, which was not statistically significant. That is 3.6 times the return from identical training. These are group averages, not a promise that every athlete gains 7.7%.
Source: Woorons, Millet and Mucci (2019). Physiological adaptations to repeated sprint training in hypoxia induced by voluntary hypoventilation at low lung volume. European Journal of Applied Physiology, 119(9), 1959 to 1970. This study compares breath hold sprint training after exhaling against normal breathing. It does not compare nasal and mouth breathing.
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