Downey, A., Chenoweth, L. M., Townsend, D. K., Ferguson, C. S., Ranum, J., & Harms, C. A. (2005). The effect of inspiratory muscle training on hypoxic exercise. Medicine and Science in Sports and Exercise, 37(5), Supplement abstract 2320.

This investigation determined if inspiratory muscle training (IMT) would have greater effects in hypoxia than in normoxia. Ss were divided into an experimental group (N = 7) and a control group (N = 5). A four-week IMT program was instituted using an IMT trainer at 50% in the experimental group and 15% maximal inspiratory pressure in the control group. Two treadmill tests to exhaustion at 80% VO2max and inspiratory muscle function were measured.

Significant IMT effects were revealed in the IMT group but not the control group. Time to exhaustion was similar in both groups. IMT training produced significant hypertrophy in the diaphragm, increased respiratory muscle strength, reduced ventilatory demand and respiratory muscle fatigue, and improved gas exchange and effort perception during heavy exercise in hypoxia.

Implication. Inspiratory muscle training improves inspiratory muscle performance but does not transfer those effects to improve aerobic performance.

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