Question : fit but not healthy

why are some folks given to fitness and diligent exercise, still get issues like heart problems etc.

thanks

Answer : fit but not healthy

Cardiovascular fitness is one aspect of health.
But you can certainly overexercise and hurt yourself.

Exercise can not correct congenital mechanical heart problems, or genetic issues
like high cholesterol.

Read about the premature death of  70's running and fitness guru of Jim Fixx:

     http://en.wikipedia.org/wiki/Jim_Fixx