Okay, so you know how when you are playing a game or doing some sports, your body gets tired and your heart beats faster? That's because your body is working hard to help you move and compete.
But sometimes, when athletes push themselves too hard or don't take care of their bodies properly, they can get hurt or get sick. For example, if you play basketball every day without taking a break, your knees might start to hurt. Or if you don't drink enough water while playing soccer in the hot sun, you might get dehydrated and feel really sick.
There are also some health issues that are common in certain sports. For example, football players are at risk of getting concussions - which is when your brain gets shaken around and can cause a lot of damage. And runners might get shin splints - which is when their leg bones start to hurt because they are working too hard.
So, it's really important for athletes to take care of their bodies and listen to what their bodies are telling them. That means drinking lots of water, eating healthy foods, and getting enough rest. It also means taking breaks sometimes and not pushing themselves too hard. If an athlete does get hurt or sick, they should see a doctor or trainer right away to get help.