RESPIRATORY TRAINING IMPROVES RESPIRATORY FUNCTION BUT NOT AEROBIC CAPACITY
Inbar, O., Weiner, P., Azgad, Y., Rotstein, A., & Weinstein, Y. (2000). Specific inspiratory muscle training in trained endurance athletes. Medicine and Science in Sports and Exercise, 32, 1233-1237.
This investigation was based on the belief that "arterial O2 desaturation occurs during maximal aerobic exercise in elite endurance athletes and that it might be associated with respiratory muscle fatigue and relative hypoventilation" (p. 1233). It was hypothesized that specific inspiratory muscle training (SMIT) would result in improved respiratory muscle function and aerobic capacity in well-trained athletes.
From 20 endurance trained athletes, two groups (N = 10) were randomly formed. The inspiratory trained group (SMIT) used a threshold inspiratory muscle trainer for 30 minutes a day, six days a week, for 10 weeks. The control group received "sham" training.
Inspiratory muscle strength and endurance improved significantly in the SMIT group, but were unchanged in the control group. These improvements were not associated with any improvement in VO2max, or in arterial desaturation in maximal exercise.
Implication. Respiratory muscle training improves respiratory muscle function but is not associated with improved aerobic capacity.