Effect of physical training on the pulmonary diffusing capacity during submaximal work.

Abstract

There is evidence suggesting superior athletes may possess "supernormal" pulmonary diffusing capacities (DL). In order to define the role of physical training in producing this supernormal DL, the effects of 5 months of vigorous physical training on DL and other cardiopulmonary characteristics, both at rest and during submaximal work in 8 freshmen candidates for the University boat crew were compared with similar observations of 8 control subjects leading normal campus lives. An analysis of covariance on the difference in responses of the training and control groups indicated training causes: bradycardia at rest and relative bradycardia during exercise, loss of adipose tissue, no effects on DL or pulmonary capillary blood volume at rest or during exercise, no changes in total blood volume. These data indicate that short-term training does not modify DL, and imply that supernormal DL values in athletes are not the result of training. A comparison of the response of DL and heart rate to 4 equal work increments up to 85% of maximal aerobic work indicates: a nonlinear response of heart rate, with a smaller increase, work increment at approximately 70% of maximal aerobic work, DL continues to rise linearly with both increasing external work and V02 (p2 uptake], and specifically does not depart from linearity at near maximal aerobic work.