What's your favorite way to sweat? Running? Lifting weights? Cardio? There are lots of ways you can exercise that will benefit your body. But what's the best exercise for your brain? That's the question recently posed by researchers at the University of Jyvaskyla in Finland, and you might be surprised by the results.

This isn't the first time researchers have looked at the effect of exercise on the brain. Past studies have shown that exercise improves cognitive ability in seniors and reduces the brain shrinkage that often coincides with aging. But this is the first time that they have put different types of exercises head-to-head to compare their brain boosting power.

For the study, published in the Journal of Physiology, researchers wanted to expand upon past studies focused on how exercise increases the number of new brain cells; their goal was to learn which type of exercise led to the biggest increase in the number of new cells.

Researchers gathered a large group of male rats, injected them with a substance that marks new brain cells as they form, and divided them into four groups based on the type of workout they would perform — running, strength training, intervals and the sedentary group that acted as a control.

The runners were given a wheel and allowed to run whenever they chose. The weightlifters were taught to climb a wall with tiny weights attached to their tails, and the mice that practiced interval training were placed on itty-bitty treadmills where they alternated between sprinting and slow jogging for 15 minutes each day.

After seven weeks, researchers took a look to see if there were any notable changes in their brains. They found that the weightlifting mice, while stronger, had no change in neurogenesis in the brain, including the growth and development of new tissue. The mice that practiced interval training had greater levels of neurogenesis than the sedentary mice, but still far fewer than the runners. But the brains of the mice that had spent their time running were teeming with new cells. Better yet, the distance they ran each day coincided with the number of new brain cells they developed.

What happens in the brains of mice may not directly translate to what might happen in the brain of a human, but the study lends credence to the idea that sustained cardio exercise is the best way to keep your brain charged and churning. In other words, running is as good for your brain as it is for your body.