Several anthropometric and performance parameters related to aerobic metabolism are associated with performance in endurance runners and are modified according to the training performed. The objective of this study was to investigate the ergospirometric and body composition changes in endurance runners during a sports season in relation to their training. Twenty highly trained men endurance runners performed an incremental test until exhaustion (initial, and at 3, 6, and 9 months) on a treadmill to determine maximal oxygen consumption (VO2 max), second ventilatory threshold (VT2), and their associated running speeds. Skinfolds, perimeters, and weights were measured. No changes were obtained in VO2 max or VT2 during the study, although their associated running speeds increased (p < 0.05) after 3 months of the study. Decreases in fat mass (p < 0.05) and muscle mass (p < 0.05) were observed at the end of the season (9 months). Changes occurred in the different skinfolds according to the characteristics of the training performed during the season. In conclusion, vVO2 max and vVT2 increase with a greater volume of kilometres trained and can be adversely affected by loss of muscle mass.
Keywords: endurance; fat mass; maximal oxygen consumption; muscle mass; skinfolds.