Effects of habitual physical activity on response to endurance training

We hypothesised that habitual physical activity (PA) together with progressive endurance training contributes to the differences in training response (Delta(V)over dotO(2max)) in healthy and physically active male participants. Twenty volunteers (age 30 +/- 3 years and (V)over dotO(2max) 54 +/- 7 ml . kg(-1) . min(-1)) participated in an eight-week training program which included four to six heart rate-guided exercise sessions weekly. PA data over the whole period were collected by an accelerometer-equipped wristwatch. Individual relative intensities of endurance training and PA were separately determined by adjusting to (V)over dotO(2max) reserve and calculated as mean daily duration (min) of training and PA at light, moderate, high and very high intensity levels. (V)over dotO(2max) increased 6.4 +/- 4.1% (p < 0.0001) during the training period. Delta(V)over dotO(2max) correlated with the amount of habitual PA that was mainly of light intensity (r = 0.53, p = 0.016), but not with the duration of moderate, high or very high intensity PA (p = ns for all). Age, body mass index, and daily amount of training at any intensity level of exercise were not related to Delta(V)over dotO(2max) (p - ns for all). In conclusion, a high amount of habitual PA together with prescribed endurance training was associated with good training response in physically active males.