Effects of respiratory muscle endurance training on maximal oxygen uptake in untrained men and women

The purpose of this study was to determine the effects of respiratory muscle endurance training on maximal oxygen uptake in untrained men and women. Twelve volunteers (six male and six female) were placed into either an experimental or control group. Both groups completed a 15-second MVV test, an endurance breathing test, and a maximal oxygen uptake test. Following these tests, the experimental group underwent a strenuous five-week training program specifically designed to increase the ventilatory endurance of the breathing muscles. Every fifth day, measurements of 15-second MVV and endurance breathing time were taken. After the training period was completed, both groups repeated the three pre-test tasks. The experimental group showed significantly greater changes than the control group in 15- second MVV (p<0.005), endurance breathing time (p<0.0005), and peak ventilation attained during the maximal oxygen uptake test (p<0.01). There were no significantly different changes in maximal oxygen uptake (.10>p>.05); however, the experimental group showed a slight increase while the control group showed a decrease. These results indicate that ventilatory endurance is enhanced by a rigorous program of respiratory muscle endurance training. Investigation of the role that respiratory muscle training plays in maintaining acid-base balance during maximal aerobic work may prove helpful in understanding performance limitation in humans.