I sleep 7-8hours at night but still sleep at afternoon for 1-2hours. even that i felt so tired i can't move my body. why? i'm 18, active in netball.

You need to do that: Every night, not just catching up on the weekends. It does not work that way . That is why you are still very tired, exhausted! if that is not the case, you need to consult with your physician to run some tests - check for hypothyroid and other medical conditions that is affecting you.Eat healthy, drink plenty and sleep 8 hours or more every night!