There's always tradeoffs; serious academic pursuit means neglecting physical fitness and life goals (relationships and fun and such). Its easier to recover from time lost on the sportsball path than time lost on the academic path.
Everyone makes sacrifices. There are reasons why pro athletes retire in their 30's. Aside from deterioration of performance, injuries start to take their toll. On the other hand nothing stops an academic from staying reasonably fit-- not enough to win races, perhaps, but easily enough to not suffer from sedentary ailments.
Relationships are difficult for anyone that pursues extreme success, athlete or academic.
