Effects of Training Once vs. Twice Per Day and Improvement in Maximal Aerobic Power

Abstract

This study was designed to determine the effects of once vs. twice daily workouts with respect to changes in maximal aerobic power (Vo^max). Thirteen varsity track men were divided into two groups for participation in interval training, once (I/day) and twice (2/day). The intensity of each workout was based primarily on maximal heart rates (max HR). After 4 weeks of training, there was no change in VO2submax within either of the groups, while submax heart rate (HR) was significantly lower for both groups. There were no differences between the groups for VO2 submax or submax HR. Vo2 max improved significantly for both groups while max HR was significantly lower for the I/day group following four weeks of training. Between group differences existed for max HR. Blood glucose (colori-metric) was significantly lower for the 2/day but not for the I/day after 4 weeks of training. The data suggest that training 2 times per day is not associated with improvements in VQ max over training one time per day.