Cardio sessions may literally make your brain bigger

When you hit the gym, chances are youre thinking more about how your body will benefit rather than how your brain will. But as it turns out, all that time spent on the treadmill is doing your noggin a serious favor.

New research from Australia's National Institute of Complementary Medicine (NICM) at Western Sydney University and the Division of Psychology and Mental Health at the University of Manchester in the U.K. shows that aerobic activity can improve your memory and overall brain health as you age.

The study, published in NeuroImage, looked at brain scans of 737 people who were either totally healthy, had mild brain deterioration (like Alzheimer's), or had a diagnosed mental illness like depression or schizophrenia. Their ages ranged from 24 to 76 years old (the average being 66).

Participants in the study did all types of cardio—the stationary bike, walking, and running—two to five times a week for anywhere between three months and two years.

By the end of the 14 clinical trials, researchers found that even though exercise didn't have an impact on the overall size of the hippocampus (the part of your brain that controls memory), the left region of it actually did get bigger.

"Our data showed that, rather than actually increasing the size of the hippocampus per se, the main 'brain benefits' are due to aerobic exercise slowing down the deterioration in brain size,"Joseph Firth, a Ph.D. research fellow at NICM, said in a statement. "In other words, exercise can be seen as a maintenance program for the brain."

This is all due to a chemical your brain creates when you do any type of aerobic exercise called brain-derived neurotrophic factor (BDNF), Firth says.

As we've reported in the past, adding 30 to 45 minutes of cardio into your weekly workout routine can also help you build muscle and burn fat.

"There is also evidence that at the right intensity and duration, cardio can build the aerobic capacity of your fast-twitch muscle cells, the ones needed to produce raw strength and power,"Chris Frankel, Ph.D., exercise physiologist and Director of Human Performance at TRX, told Men's Health in 2015. "That can potentially improve your lifting performance."

So the next time you're heading to the gym, think about how much cardio you've gotten in lately. Your brain will thank you.