answer:I had a childhood illness that weakened my body considerably, and I’ve had to work my way back to everything, starting with the endurance to make it through a whole day of middle school without taking a nap. It’s been a long road, but I’ve actually managed to get back into running. I’m not a world class athlete or anything just yet. I’ll be honest—my best mile time is 10:00 minutes on the dot. There’s nothing you can do to really prepare your body for running. If you’re allowed to walk, or do any kind of aerobic exercise that would help. Definitely eat healthy, but I’m sure you already know both of those. I read this blog on runnersworld.com, and I’ve read several discussions about this type of issue. The author has also written a number of books that might be helpful.