Coping with Reduced Oxygen (Hypoxia)
and Higher Carbon Dioxide (Hypercapnia)

If you took a moderately paced run alongside an elite athlete, you would expect that his or her breathing would be light, rhythmic, easy, and effortless. You certainly wouldn’t expect him to be huffing and puffing like a steam train.

A study by Japanese researchers Miharu Miyamura and colleagues from Nagoya University, of ten marathon runners and 14 untrained individuals found that athletes had a significantly greater tolerance to carbon dioxide at rest when compared with untrained individuals. The study found that for the same amount of exercise, athletes experienced 50 to 60 percent less breathlessness than that of untrained individuals [1].

It has been said that one of the main differences between endurance athletes and non-athletes is their response to low pressures of oxygen (hypoxia) and higher levels of carbon dioxide (hypercapnia) [2,3]. In a paper entitled, ‘Low exercise ventilation in endurance athletes’, that was published in Medicine and Science in Sports, the authors found that non-athletes breathe far heavier and faster to changes in oxygen and carbon dioxide when compared with endurance athletes at equal workloads. The authors observed that the lighter breathing of the athlete group may explain the link between “low ventilatory chemosensitivity and outstanding endurance athletic performance [3].”

In a study by Woorons, it was noted that trained athletes had a lower ventilation than untrained men. This was probably due to a weaker hypercapnic ventilatory responsiveness (improved tolerance to carbon dioxide) in trained athletes [4].

In other words, endurance athletes are able to tolerate a greater concentration of carbon dioxide and lower concentration of oxygen in the blood during exercise. Intense physical exercise results in increased consumption of oxygen and increased production of carbon dioxide, so it is vitally important that athletes are able to cope well with these blood gas changes.

Reduced breathing frequency has been shown to reduce the ventilatory response to carbon dioxide [5,6,7]. Holmer and Gullstrand suggested that breath controlled induced hypercapnia during training may actually be the determining factor in improving performance, instead of the coveted hypoxic training technique [8].

In order to attain outstanding performance during sports, it is essential that your breathing does not react too strongly to increased concentrations of carbon dioxide and decreased concentrations of oxygen. Over time, intense physical training will help to condition the body to better tolerate these changes, but a more effective method can be found in the Oxygen Advantage® program. By applying breathing exercises to address dysfunctional breathing as well as practising simulation of high altitude training, the body makes adaptations to better cope with low oxygen and higher carbon dioxide.


  1. Miyamura M, Yamashina T, Honda Y, Ventilatory responses to CO2 rebreathing at rest and during exercise in untrained subjects and athletes. The Japanese Journal of Physiology 1976; 26: 245-54
  2. Scoggin et al. stated that, “one difference between endurance athletes and non-athletes is decreased ventilatory responsiveness to hypoxia (low oxygen) and hypercapnia (higher carbon dioxide).” See: Scoggin CH, Doekel RD, Kryger MH, Zwillich CW, Weil JV. Familial aspects of decreased hypoxic drive in endurance athletes. Journal Applied Physiology 1978;(Mar;44(3)):464-8
  3. Martin BJ, Sparks KE, Zwillich CW, Weil JV. Low exercise ventilation in endurance athletes. Med Sci Sports.1979;(Summer;11(2):):181-5
  4. Woorons1, P. Mollard1, A. Pichon1, C. Lamberto1,2, A. Duvallet1,2, J.-P. Richalet. Moderate exercise in hypoxia induces a greater arterial desaturation in trained than untrained men. Scand J Med Sci Sports 2007: 17: 431–436
  5. Jakovljevic DG, McConnell AK. Influence of different breathing frequencies on the severity of inspiratory muscle fatigue induced by high-intensity front crawl swimming. J Strength Cond Res, 2009; 23, 1169-1174.
  6. Kapus J, Kapus V, Štrumbelj B. Ušaj A.Can high intensity workloads be simulated at moderate intensities by reduced breathing frequency? Biol Sport, 2010a; 27, 163-168.
  7. Kapus J, Ušaj A, Lomax M. Adaptation of endurance training with a reduced breathing frequency. J Sports Sci Med, 2013;12 (4), 744-752.
  8. Holmer I, Gullstrand L (1980) Physiological responses to swimming with a controlled frequency of breathing. Scand J Sports Sci 2: 1-6.