Fitness

Swimming is a good recuperative option. The worst I ever had such was just after the first marathon which was more run the first half, limp the second. Pay attention to what feels normal for you, I'm a 230+ LB person myself and have found that anything upwards of 10 miles starts really running the risk of being put down for a few days after. Good proper running shoes that fit your stride are a big factor too. If you're one to keep up on the ball of the foot having a high heel to it helps level out the impact, versus those that run more flat. There's a lot of weird mechanics to running, but at the start just taking a jog down the street and actively think about just how you run can give a lot of hints.