As hard as it is for adults to admit, kids get tired. I think that mostly they get tired of being on a tight schedule. Physically, after a few days, they should be good to switch sports, but I remember when I was in HS it was great to have that week off. Usually, about Wednesday, it was time to get back to work. Coach Gable has the right idea on that. What you do in late February is much more important than what you do in late November.