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 (Δ[V(·)]O(2max)) in healthy and physically active male participants. Twenty volunteers (age 30±3 years and [V(·)]O(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(·)]O(2max) reserve and calculated as mean daily duration (min) of training and PA at light, moderate, high and very high intensity levels. [V(·)]O(2max) increased 6.4±4.1% (p < 0.0001) during the training period. Δ[V(·)]O(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 Δ[V(·)]O(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.