Effects of aerobic training intensity on executive functions in middle-to-old age adults

The beneficial effects of physical exercise, especially aerobic training, on cognitive functions in middle or old age adults have been demonstrated in a sizable amount of recent studies. However, the majority of these research works mainly contrasts the difference between the training and the non-training control groups. Hence their results only reflect the pre- vs. post-training difference between groups ＂with＂ and ＂without＂ training, and do not reveal the training effect parametrically. The current study aims to investigate how aerobic training with different intensity influences executive functions in middle-to-old age people. Two groups of middle-to-old adults were recruited and randomly assigned to a low-intensity (40% HRR) and a moderate intensity (60% HRR) group for a 12-week cyclic ergometer training program. Tests for components of executive functions, including shifting, inhibition, and updating, were administered immediately before, during, and immediately after the training program. We found that moderate intensity training effectively enhanced physical fitness, in terms of six-minute walking distance, to a larger extent than low intensity. Among the three components of executive function, only the mixing cost of task-switching showed dependence on training intensity in terms of both acute and long-term effect. In conclusion, intensity of aerobic training does not uniformly modulate all components of executive function.