This is exactly how much exercise you need for a sharper brain, according to science

It goes without saying that most of us work out for our waistline, but there’s an added benefit to hitting the treadmill a few times a week: Improved cognitive performance. Huzzah!

But exactly how much fitness do you need to reap the rewards of a sharper brain? According to a recent study published in the Journal of Neurology and Clinical Practice, it’s not actually a ton.

Researchers found that low intensity exercise for a cumulative total of 52 hours over the course of six months—about four hours a week—is enough to see serious brain benefits, including global cognition, processing speed and attention span and executive function (a set of mental skills that help you get things done).

Better start thinking about renewing that gym membership.