Is it possible to be really strong and really smart?

Okay I've been a super nerd most of my life and got no attention from girls. I have also done really well in school and have been out of shape. So recently I started doing P90X and have come a long way. I'm getting in shape, building muscle and girls are calling me attractive and making out with me. But I'm so freaking tired. I never want to study, my grades are still good but I keep making stupid mistakes in the lab and on random questions my professor asks me. So is it just me. I don't know. How come all the smart people I know are out of shape and all the meat heads are failing tests and quizes. There's always the stereotypical jock who never finishes college. How can I be both. Can someone give me an example of someone who was a famous athlete and an academic. Not someone who was both but famous for one but someone who was famous for both. And don't say Ozymandias from Watchmen.