We know that exercise is good for the long-term health of our brains. Now a new study from the University of Michigan Medical School and Finland’s University of Jyväskylä has identified the kinds of workouts that may be most beneficial. Researchers had rats do high-intensity interval training on treadmills, resistance training by climbing a ladder with tiny weights on their tails, and aerobic training on running wheels. Six to eight weeks later, they studied tissue from each rat’s hippocampus, a key part of the brain for memory and learning. Here’s what they found:
Rats that did resistance training were stronger than when they started, but their brains showed no signs of new cell growth compared with those of control animals. Researchers say this training probably leads to other positive changes, such as the creation of blood vessels and new connections between brain cells.
Rats that did interval training were certainly fitter and had some new neurons in their brains, but researchers believe that the intensity of the workouts may stress the body and undercut certain brain benefits.
Rats that did aerobic training showed robust neurogenesis (the creation of new brain cells), and the farther they ran, the more new cells their brains created. Other studies have found that aerobic workouts — including activities such as cycling, running, and cross-country skiing — can double or even triple the number of new neurons in test animals’ hippocampi.