Just like your other organs, your brain needs a constant supply of oxygen and other nutrients. Your circulatory system delivers this oxygen and nutrients through your circulatory system. Exercise increases your circulation. This means more nutrient-rich blood cycles throughout your body and to your brain, keeping it healthy.

Cardio exercise also increases the number of mitochondria in your body. Mitochondria are cellular structures that allow our bodies to make and use energy. Researchers think the increase in mitochondria is the reason you feel ‘sharper’ or more mentally aware after exercise. Science also suggests that keeping your heart rate elevated increases neurogenesis, which is the ability to grow new brain cells.

So, what exactly is cardio? A good cardio workout elevates your heart rate and gets your blood flowing, delivering oxygen and vital nutrients to your brain. There’s a mathematical formula you can use to figure out exactly how much your heart rate should increase, but you don’t need to do math to get a good workout. You can simply think of cardio as any exercise that gets your heart pumping and leaves you out of breath.

If you’re not sure what it feels like to do cardio, here’s a little tip to figure it out:

Find a fast song you love. The faster, the better. For the entire length of your song, dance like no one’s watching. Go wild! Jump up and down! Shake your booty! Move your arms! Keep dancing until the song is over. You’ll most likely be out of breath.

Next time you workout, try to replicate this feeling. It’s the feeling of a good cardio workout.