Athletic Performance

Train Your
Breath.

The Missing Link in Athletic Performance

Your breathing muscles fatigue just like any other muscle — and when they do, they steal blood from your legs. Core stability, oxygen efficiency, and recovery all start with how you breathe.

Explore the Science
50% Of people with lower back pain have dysfunctional breathing
42% More water loss when breathing through the mouth
↑ O₂ Better oxygen extraction per breath (Dallam, 2018)
01

The Metaboreflex: When Breathing Steals Your Performance

When your breathing muscles start to fatigue during intense exercise, they require more oxygen and 'steal' blood that should be going to your legs for running. This happens through an autonomic reflex called the metaboreflex — and it's one of the most underappreciated limiters of endurance performance.

  • Fatigued respiratory muscles trigger the metaboreflex
  • Blood flow is redirected from locomotor muscles to respiratory muscles
  • This accelerates leg fatigue and limits performance
  • Training nasal breathing strengthens respiratory muscles and delays this reflex
Normal State
Legs ← Blood
Blood flows to locomotor muscles
Metaboreflex Triggered
Legs ← Blood → Breathing
Blood stolen from legs to respiratory muscles
Nasal Breathing Trained
Legs ← Blood
Respiratory muscles stronger, reflex delayed
02

Core Stability & the Diaphragm

The stability of the trunk and pelvis is essential for athletic performance and injury prevention — but also for anyone who wants to enjoy a good quality of life. Instability around the pelvis can cause excess movement in other joints.

  • Trunk neuromuscular control prospectively predicts distal joint injury — lateral trunk displacement was the single strongest predictor of knee, ligament, and ACL injuries in a 3-year cohort of 277 collegiate athletes (Zazulak et al., 2007)
  • Lumbar instability propagates up the kinetic chain — thoracic stiffness and shoulder compensation can drive overuse injuries including rotator cuff strain
  • Diaphragmatic breathing creates intra-abdominal pressure (IAP) that stabilizes the core
  • Chronic low back pain patients show altered diaphragm recruitment under postural load — the anterior/middle diaphragm fails to descend while the crural portion compensates, and respiratory drive begins to substitute for postural function (Kolář et al., 2012)
  • 50–70% of chronic low back pain patients adopt an altered breathing pattern (breath-holding, paradoxical, or upper-costal) during lumbopelvic motor-control challenge, vs 0% of pain-free controls — independent of pain severity (Roussel et al., 2009)
  • This is the foundation of all functional movement
Breathing dysfunction doesn't just affect your lungs — it cascades through your entire kinetic chain.
References
  1. Zazulak BT, Hewett TE, Reeves NP, Goldberg B, Cholewicki J. Deficits in neuromuscular control of the trunk predict knee injury risk: a prospective biomechanical-epidemiologic study. Am J Sports Med 35(7):1123–1130, 2007. DOI: 10.1177/0363546507301585
  2. Kolář P, Šulc J, Kynčl M, et al. Postural function of the diaphragm in persons with and without chronic low back pain. J Orthop Sports Phys Ther 42(4):352–362, 2012. DOI: 10.2519/jospt.2012.3830
  3. Roussel N, Nijs J, Truijen S, Vervecken L, Mottram S, Stassijns G. Altered breathing patterns during lumbopelvic motor control tests in chronic low back pain: a case–control study. Eur Spine J 18(7):1066–1073, 2009. DOI: 10.1007/s00586-009-1020-y
Injury Cascade
Lumbar instability
Thoracic stiffness
Shoulder compensation
Rotator cuff injury
03

Exercise Performance Benefits

Nasal breathing during exercise isn't just about filtration — it fundamentally changes how efficiently your body uses oxygen and manages fatigue.

  • Stay more hydrated — mouth breathing causes 42% more water loss compared to nasal breathing
  • Better oxygen utilization — breathing through the nose lowers the fraction of expired O₂ (FEO₂), indicating more oxygen extracted per breath from lungs and blood to working muscles (Dallam et al., 2018)
  • Reduced ventilation — body adapts to higher CO₂ tolerance, leading to reduced breathlessness and greater economy. Ventilation was reduced by 22% in nasal breathing (Dallam et al., 2018)
  • Improved running economy — at 85% maximum velocity, oxygen cost was ~4% lower under nasal breathing, with no significant difference in VO₂max or peak lactate (Dallam et al., 2018)
  • Reduced exercise-induced bronchoconstriction
References
  1. Dallam GM, McClaran SR, Cox DG, Foust CP. Effect of nasal versus oral breathing on VO₂max and physiological economy in recreational runners. Int J Kinesiol Sports Sci 6(2):22–29, 2018.
04

Breath-Hold Training: Altitude Without the Mountain

Athletes have chased the benefits of altitude for decades — but you don't need a mountain or a hypoxic tent. By exhaling and then holding the breath through short, hard efforts, you can briefly drop your blood-oxygen level into the altitude range and raise CO₂ at the same time — a dual stimulus that pure altitude can't reproduce. This is the signature method of the Oxygen Advantage approach.

  • Real desaturation, at sea level — holding the breath at low lung volume during exercise drops oxygen saturation to ~85–88%, comparable to ~2,400 m altitude, while CO₂ rises and right-shifts the oxygen–dissociation curve (the Bohr effect) (Woorons et al., 2011)
  • Large, repeatable gains in repeated-sprint ability — 3–4 weeks of breath-hold sprint training increased sprints-to-exhaustion by +35% in swimmers (Trincat et al., 2016) and +64% in rugby runners (Woorons et al., 2018); chamber-based versions show similar +38% gains in cyclists (Faiss et al., 2013)
  • The benefit carries across sports — gains trained in cycling or swimming transfer to running tests, pointing to central adaptations, not just local ones
  • Sprint quality is preserved — although brain oxygenation dips during the holds, sprint performance held up, because oxygen recovers quickly between efforts (Woorons et al., 2019)
  • Intensity is the catch — these gains only appear at genuinely hard, near-maximal efforts. Gentle breath-holds during easy exercise don't reproduce them
This is a targeted tool for repeated-sprint and team-sport fitness — not a replacement for aerobic base training. It sharpens fatigue resistance across many sprints, not VO₂max.
Practice safely: Deliberate desaturation places real stress on the heart and brain. Breath-hold training is best learned and progressed with a qualified coach, and is not appropriate during pregnancy or for anyone with cardiovascular, cerebrovascular, or uncontrolled blood-pressure conditions. Never practice breath-holds in or near water without direct, trained supervision.
References
  1. Woorons X, Bourdillon N, Vandewalle H, et al. Cardiovascular responses during hypoventilation at exercise. Int J Sports Med 32(6):438–445, 2011.
  2. Faiss R, Léger B, Vesin JM, et al. Significant molecular and systemic adaptations after repeated sprint training in hypoxia. PLoS One 8(2):e56522, 2013.
  3. Trincat L, Woorons X, Millet GP. Repeated-sprint training in hypoxia induced by voluntary hypoventilation in swimming. Int J Sports Physiol Perform, 2016.
  4. Woorons X, Billaut F, Vandewalle H. Repeated-sprint training in hypoxia induced by voluntary hypoventilation improves running repeated-sprint ability in rugby players. Eur J Sport Sci, 2018.
  5. Woorons X, Mucci P, Millet GP, et al. Cerebral and muscle oxygenation during repeated-sprint exercise with voluntary hypoventilation. Eur J Appl Physiol, 2019.
Normal Breathing
SpO₂ ~98%
Sea-level oxygen saturation
Breath-Hold Sprint
SpO₂ ~85–88%
≈ 2,400 m altitude + rising CO₂
After 3–4 Weeks
+35–64% Sprints
More sprints before exhaustion
05

Train the Breathing Muscles Themselves

Remember the metaboreflex — fatigued breathing muscles stealing blood from your legs? You can attack it directly. Just like any other muscle, the diaphragm and the muscles you inhale with can be strengthened with resistance — and a stronger inspiratory pump fatigues later, delaying the blood-stealing reflex.

  • A simple, proven protocol — breathing against a handheld resistance device, ~30 breaths twice a day at moderate load for 4–6 weeks, raises maximal inspiratory strength by 20–50% (Romer et al., 2002)
  • It translates to performance — a meta-analysis of 46 studies found respiratory-muscle training improved endurance performance by ~16% on constant-load tests and ~18% on intermittent tests (Illi et al., 2012)
  • The mechanism is the metaboreflex — researchers showed that fatiguing the inspiratory muscles cut exercising-limb endurance by 37% via blood-flow stealing, and that training raised the threshold at which this kicks in (McConnell & Lomax, 2006)
  • Who gains most — less-fit athletes and those competing in longer events (>10 min) see the biggest effects; team-sport athletes benefit through faster sprint recovery
  • What it won't do — it doesn't raise VO₂max. Performance and VO₂max aren't the same thing — this works by delaying fatigue, not by raising your aerobic ceiling
Breath-hold training and inspiratory muscle training are complementary: one trains your tolerance to low oxygen and high CO₂, the other strengthens the pump that moves the air.
References
  1. Romer LM, McConnell AK, Jones DA. Effects of inspiratory muscle training upon recovery time during high intensity, repetitive sprint activity. Int J Sports Med 23(5):353–360, 2002.
  2. Illi SK, Held U, Frank I, Spengler CM. Effect of respiratory muscle training on exercise performance in healthy individuals: a systematic review and meta-analysis. Sports Med 42(8):707–724, 2012.
  3. McConnell AK, Lomax M. The influence of inspiratory muscle work history and specific inspiratory muscle training upon human limb muscle fatigue. J Physiol 577(1):445–457, 2006. DOI: 10.1113/jphysiol.2006.117614
Inspiratory Muscle Training
Stronger diaphragm
Breathing muscles fatigue later
Metaboreflex delayed
More blood to legs, later fatigue
A

Breathing Pattern Disorders in Athletes

Breathing pattern disorders should be considered in the orthopedic assessment of physically active patients (Chapman et al., 2016). Dysfunctional breathing creates compensatory movement patterns that can increase injury risk throughout the kinetic chain.

References
  1. Chapman et al., Int J Sports Phys Ther, 2016
B

The Endurance Edge

Key paradoxical idea: breathing less actually helps extract more oxygen via the Bohr effect. Reducing tidal volume — the amount of air per breath — increases efficiency. The body adapts to higher CO₂ tolerance, reducing breathlessness and improving economy.

Nasal vs Mouth Breathing During Exercise

A side-by-side comparison of breathing strategies for athletic performance

MetricNasalMouth
O₂ extractionMore efficientLess efficient
Ventilation volumeReduced 22%Baseline
Running economy (85% Vmax)~4% lower VO₂Baseline
HydrationConservedAccelerated loss
Core stabilityEnhanced via IAPCompromised
BronchoconstrictionReducedIncreased risk
Respiratory muscle fatigueDelayedEarlier onset
Recovery markersBetter HRVWorse HRV