Acute Effects of Intermittent Physical Activity on Perceptions of Exercise-Related Fatigue in Children.

PURPOSE: To investigate the acute effects of intermittent activity performed at varying intensities on the perceptions of exercise-related fatigue in children. METHODS: A total of 30 children completed 4 experimental conditions in random order, which consisted of 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity activity breaks or 20 two-minute sedentary breaks. The perceptions of exercise-related fatigue were determined via the Subjective Exercise Experience Scale at the beginning (0 breaks), middle (after 10 breaks), and end (after 20 breaks) of each condition. RESULTS: The average heart rate was significantly higher with increasing exercise intensity (sedentary: 89.6 +/- 1.2 beats/min, low: 114.6 +/- 1.8 beats/min, moderate: 147.2 +/- 1.8 beats/min, and high: 172.3 +/- 1.8 beats/min, P < .0001). There was no significant main effect of condition (sedentary: -0.5 +/- 0.6, low: -1.0 +/- 0.7, moderate: -0.2 +/- 0.5, and high: -0.6 +/- 1.2; P = .86) and time (10-0 breaks: -0.7 +/- 0.5 and 20-0 breaks: -0.5 +/- 0.5; P = .45), nor time by condition interaction (P = .99) on change in exercise-related fatigue. CONCLUSIONS: Incorporating intermittent activity into physical activity programs may help to reduce barriers to regular exercise by minimizing perceptions of exercise-related fatigue in children.