Maybe I should start by saying that I have never considered an athletic human being. I'm just not very coordinated, I fall down a lot and I just never thought I was very good at sports. However, at my school, I still had to play them. And if you're like me, here's some tips to surviving gym when you're not athletic.
To start, see if you can talk with your gym teacher about where you're struggling. Maybe he or she can show you some stretches or exercises you could do outside of class to improve your fitness. Or maybe they can tell you what you're going to be doing next class. Just knowing what you're going to be doing can make you feel a little more comfortable with it and then when you show up to class you won't feel completely caught off guard like, "Oh my god, what is this? I don't know what we're doing." You'll know, you'll feel a little more comfortable.
Even if you're not going to be the fastest runner in the race, give it 110 percent when you're in class or when you're doing your sport. I did cross country my senior year of high school just to kind of prove to myself that I could do it, and I finished last almost every single race. But I finished the races and that is what ended up being important to me, and my team, and my coaches.
Another thing that I still struggle with is, don't say that you're bad at sports. Don't put yourself down like that and say, "Oh my god. I'm so bad I can't do it." It's okay to say, "Yeah I'm uncoordinated, like I am, I'm totally uncoordinated." But be more confident about it. Show up on the field or show up in gym class ready to do it and say, "Yeah I can do this."
And like I said, even if you don't finish first doesn't mean you're not going to finish the race.