ABSTRACT
Present study aimed to examine the effects of high-intensity intermittent training on metabolic or circulatory parameters and exercise time during 30s-lasting exhaustive exercise. Six healthy males (22 ± 1yrs) had an intermittent training four days a week for four weeks. The intermittent training consisted of 8 or more sets of 20s exercise bout at an intensity of 170%VO2 max separated by 10-s recovery. Before and after training period, VO2 max and maximal accumulated O2 deficit (MAOD) were determined as indices of metabolic capacity. During 30s-lasting exhaustive exercise, VO2, O2 deficit, and circulatory parameters, such as heart rate, stroke volume, and cardiac output, were also determined every 10s. After the training, VO2 max and MAOD were significantly increased. During 30s-lasting exhaustive exercise, exercise time, stroke volume, and cardiac output were also significantly enhanced. However, no significant differences were observed in VO2 and O2 deficit every 10s during 30s-lasting exhaustive exercise. Therefore, these findings suggest that high-intensity intermittent training enhances exercise time during 30s-lasting exhaustive exercise and that the improvement of exercise performance is closely related to an increase in anaerobic capacity.
ABSTRACT
This study aimed to clarify the effects of a lifestyle intervention by the concurrent use of an activity monitor and Twitter on daily physical activity. Twenty-one healthy males and females (37 ± 13 yrs) were randomly assigned to Normal intervention group (N group, n = 10) or Twitter intervention group (T group, n = 11). In both groups, the intervention period was 6 weeks. Participants in N group wore an activity monitor (Lifecorder EX). Meanwhile, participants in T group were asked to tweet about their daily steps or physical activity in addition to wearing an activity monitor, and also an observer read through the tweet from each participant and commented about physical activity. There were no significant differences in daily physical activity (<i>i.e</i>., steps and amount of physical activity (PA)) at week 1 between both groups. In addition, no significant time-course changes in steps and amount of PA were observed in N group. In contrast, steps in T group were gradually increased from week 1 8,542 ± 3,158 steps/day to week 6 12,700 ± 3,935 steps/day (P < 0.01). Amount of PA in T group was also gradually increased from week 1 2.5 ± 1.2 METs·hour/day to week 6 4.6 ± 2.3 METs·hour/day (P < 0.01). Therefore, these findings indicate that the lifestyle intervention by the concurrent use of an activity monitor and Twitter could effectively induce an increase in daily physical activity compared with the intervention using only an activity monitor.