When you’re happy, this is what really happens to your body.

There are a lot of reasons why happy people are a lot healthier than most, and one of them is because they’re sick a lot less often. That’s right, happiness has quite an effect on your immune system. When we find ourselves in a good mood, we tend to stress less. “Less stress means that your body is not producing high amounts of cortisol,” clinical psychologist Dr. Cali Estes told Health Digest. This chemical is known to suppress our immune systems, so being happy could just be what prevents you from catching a common cold.

People who are happy may be able to get more out of their workouts too. “You will get more reps in, more steps in or more yoga in,” clinical psychologist Dr. Cali Estes told us. That’s because working out increases the amount of serotonin and dopamine that our brains make, two of the four happy chemicals that our brains constantly crave. This explains why many people claim that exercise quickly becomes addictive.

If thinking about hitting the gym isn’t such a happy thought, Dr. Estes suggests cranking up your favorite tunes as you work on getting toned. “The music makes their serotonin go up and they feel happy,” she said. Read more.