I competed L 10 for 5 years through middle and high school and my mom never called me in sick so I could do homework. She worked at the school and refused to let me do gymnastics, even if it was a meet, if I got behind in school. I got the threat of not going to nationals because I hadn't finished my science fair project in 7th grade lol. You can do it, just communicate with your teachers, see if you can get the week's homework ahead of time, do as much before and during school (like at lunch) as you can. Keep a planner! You also learn great ways to get more work done more quickly, by finding study aids that work. Flashcards helped me lots and I would laminate them and do them in the shower for example. I'm not really academically gifted, school always was a challenge for me, I just worked super hard. So if I can do it a lot of other gymnasts can!