The effects of two types of training on lung parameters relating to swim buoyancy in Homo sapiens and the relative contributions of fat and air in this regard

Over a period of three months of swim training, no significant increase in forced expiratory volume per one second (FEV1.0) and residual lung volume per kg. of body weight occurred in human subjects. However, the distance swim group (using long workouts with relatively little rest) showed a significant increase in vital capacity per kg. of body weight over a control group. In contrast, the sprint group showed no such effect using a workout of less distance and more rest. Both the distance and sprint swim groups had greater vital capacities per kg. body weight and higher residual lung volume (using Wilmore's predictive residual volume formula) at both the mid and post seasons than the control group. This suggests that both swim groups might have more buoyancy from internal air than the control group. Single tests done at the postseason only showed no differences between the two swim groups and the control in regards to percent body fat, buoyancy per kg. of body weight, FEV 1.0 per kg. of fat-free mass, residual volume per kg. of body weight (Helium dilution method). However, using Wilmore's predictive values for residual volumes, the distance swim group had significantly higher values than the control group. This indicates that the distance group might have some evidence for air buoyancy for its non-fat tissues (bone and muscle).