Few Structural Brain Changes Associated With Moderate-Intensity Interval Training and Low-Intensity Continuous Training in a Randomized Trial of Fitness and Older Adults.

This study utilized a randomized control trial to examine whether structural changes in the precuneus, insula, caudate, hippocampus, and putamen were related to exercise. A total of 197 healthy older adults with no evidence of dementia participated in moderate-intensity interval training or low-intensity continuous training for 16 weeks. Size decreased in the right hippocampus such that the effect of time was significant but the interaction with condition was not. For the left hippocampus, size decreased in the low-intensity continuous training condition but increased in the moderate-intensity continuous training plus interval training condition at the trend level. Finally, there was a significant time-by-condition interaction such that the thickness of the left insula increased for low-intensity continuous training and decreased for moderate-intensity continuous training plus interval training. Few structural changes were associated with the exercise intervention. Future studies should examine the effects of exercise on brain structure in high-risk or clinical populations for a longer period of time.