A recent article from The New York Times brings up a question that many of us have been asking ourselves for years. What kind of exercise is really best for my brain? With the introduction of new fitness routines, namely high-intensity interval training (HIIT), more and more people have been shying away from traditional cardiovascular exercises like running and cycling to HIIT exercises, which involve short intervals of sprints or heavy lifting. So, when it comes to exercise and the brain, which is more beneficial?
A study carried out by the University of Jyvaskyla in Finland and published in the Journal of Physiology brings a new meaning to the term “gym rat”. By injecting rats with a substance that allowed scientists to track the neuroregeneration, or creation of new neurons in the hippocampus of the brain, they were able to accurately see the changes that different exercises have on the brain. The study used four different groups of rats- a control group (sedentary), a running group, a weight-lifting group, and a HIIT group.
The Study- Exercise and the Brain
Over the course of seven weeks, each of the groups were given exercises to do. The running group had treadmills and running wheels to jog on, and ran up to a few miles a day. The weight lifting group had weights tied to their tails and climbed up walls. Finally, the high intensity interval training group was made to run sprints for a certain period of time, recover, and continue with a sprint, repeating this process for 15 minutes at a time. The neurogenesis of each of the groups was tracked to find which one had the most positive change in their hippocampal tissue.
After the course of the study, the running group had a noticeable increase in brain-derrived neurotrophic factor, a substance that regulates neurogenesis. Even more, the further that the rat ran, the more new neurons its brain had. This shows that there is a direct correlation between the amount of distance they ran and the amount of new neurons they generated.
The animals that followed a regimen of high intensity interval training, while showing significantly less neurogeneration than the runners, still increased neurons much more than the sedentary control group.
The final group, the real gym rats that practiced a weight training program, showed no neurogenesis. While they were clearly working out and improving other parts of their body, their hippocampal tissue looked like the control group that had not exercised at all.
What’s the Take Away?
This study answers some interesting questions and brings up even more. Does this mean that Crossfit is bad for you, or that your weight-loss regimen could be damaging your brain health? Not at all. Keeping an active lifestyle, especially as we age, is very important. This active lifestyle doesn’t only extend to physical health, but to mental health as well. Neurogeneration keeps our brains fit. It helps prevent many of the memory problems that come with aging and keeps our entire body working well.
So, you don’t have to give up your weight-lifting, but think about adding some running or long-distance endurance training into your weekly routine.