They 've said it 's had a dramatic effect once they 've gone back into marathon training .
I 've known a couple people who have taken a break from marathoning and have concentrated on just 5Ks or 10Ks for a season .
people 've said it 's had a dramatic effect once people 've gone back into marathon training .
I 've known a couple people who have taken a break from marathoning and have concentrated on just 5Ks or 10Ks for a season .