Maximal ventilation after exhausting exercise.

It remains unclear whether the hyperpnea of exercise severely stresses the ventilatory musculature. We hypothesized that the ability to ventilate maximally is decreased during and immediately following exhausting exercise. Subjects performed isocapnic maximal voluntary ventilations (60-s MVV) before, during the final minute, and after exhausting treadmill exercise lasting either 3-10 min or 60 min. Severe exercise lasting 3-10 min failed to change the 60-s MVV. In contrast, during the final minute and 5 and 10 min after 60 min of exhausting exercise, eight non-runners showed significantly lower (P less than 0.01) 60-s MVV values in comparison to control values. Eight runners had a lower (P less than 0.05) 60-s MVV 10 min post-exercise as compared with control and exercise values. Our data suggest that the capacity to ventilate maximally declines only in long-term exhausting exercise and that this decrement in most pronounced in non-runners.