After studying a lot, I need to take a break. Maybe I'll have a coffee or go for a walk. My brain feels full, and I need to do something active to use up extra energy. But after sports, I'm very tired and don't want to do much. I can't sleep because I still feel energetic. I just sit and relax for a bit, watch a movie, or have a snack. When I think about it, these kinds of tiredness are quite different.

When you're tired from studying, it's usually your brain that needs a break. You might need some rest or maybe just relax to recover. But with exercise, it's different. Your body needs physical rest and good nutrition to get back to normal. Both are tiring, but they need different things to bounce back.