Many people assume that fitness and strength training is all about building a strong body. 

But if you regularly sweat it out during a strength training session, zen out in a yoga class, or hit the pavement for an after-work run, you’ll build more than a strong body—you’ll also build a strong mind.

But how, exactly, does fitness not just improve your physical strength—but your mental strength? Let’s take a look at four science-backed ways exercise can help you strengthen your brain while you’re strengthening your muscles.

Exercise can help you build a lot of muscle—but it can also help you build resilience. In one study, researchers examined how exercise impacts rats’ capacity to deal with stress. During the study, rats were split into two groups; a group that regularly exercises and a group that didn’t. The rates were then introduced to an external stressor (cold water). After being introduced to the water, researchers measured the rats’ brain activity after being exposed to the cold water—and found that rats who regularly exercised were able to better regulate their stress and anxiety response than their sedentary counterparts.

So, what does this mean for humans? While more research is needed, this study points to the idea that regular exercise may actually change the way your brain responds to stress—increasing resilience and better equipping you to deal with any stressors that may come your way.

Exercise does your body good—but, as it turns out, it also does your mind good. Exercise produces a variety of “feel good” neurotransmitters and hormones (including dopamine, serotonin, and endorphins), which can deliver a major boost to your mood. Plus, research has found that people who exercise regularly experience significantly less depression, anger, and stress than people who exercise infrequently or not at all.

So, next time you find yourself in a bad mood and want to get yourself to a happier, better place? Getting your sweat on may be just what you need to give your mood a much-needed boost.

One major element of being mentally strong is feeling good about who you are. And a solid way to increase self-esteem and start feeling better about yourself? You guessed it—fitness.

Research has found that exercise can have a positive effect on self-esteem. So, if you have moments where you struggle with challenging feelings about yourself, your character, or your value (and, let’s be real—who doesn’t?), lacing up your shoes and getting in a good workout may really help you to start pushing your self-esteem in the right direction.

Exercise is one of the best habits you can cultivate for your health—both mental and physical. But exercise isn’t just a good habit in itself; if you get into the habit of regular exercise, it can actually help you cultivate other good habits—and help make you a happier, healthier person all-around.

This concept, that successfully changing one behavior for the better can also help you change other behaviors, is called the domino effect—and there’s science to back it up.

A study from Northwestern University’s Feinberg School of Medicine found that when participants reduced their sedentary time each day, they also ended up reducing their daily fat intake, even though they weren’t instructed to change their eating habits. Or, in other words, when people replaced the time they spent on the couch with more productive activities, they also, by default, curbed their snacking, cutting back on fatty, not-so-healthy foods.

So, if you don’t regularly exercise, and then change that behavior and get into an exercise routine, that one change can have a domino effect, inspiring changes to other areas of your life. For example, as you get into the habit of exercising, you might also start eating better, curb your screen time, or start meditating—even if changing your diet, limiting your TV time, or learning to meditate weren’t your original goals.

Exercising is one of the best ways to build physical strength—but it’s a great way to build mental strength, too. And now that you know exactly how working on your physical strength can make you mentally strong, all that’s left to do? Get out there and make exercise a priority—and become stronger, mentally and physically, in the process.