Effect of physical training on immunoreactive gamma-glutamyltransferase in human plasma

The effects of 10-week physical training on both the activity and concentration of gamma-glutamyltransferase (gamma-GT) in plasma were investigated on 7 sedentary healthy male students. The training consisted of running over 5 km, 6 times/week. The maximal oxygen uptake (Vo2max) and 12-min field performance increased significantly after training, from 43.5 and 2,683.7 to 48.1 ml.kg-1.min-1 and 2,931.1 m, respectively. After training the resting plasma gamma-GT concentration decreased to half, whereas the gamma-GT activity did not vary substantially. The training did not affect the response to the Vo2max test of either concentration or activity of gamma-GT. These results may suggest that plasma gamma-GT concentration is useful as an index of the extent of physical training.