Notes: remember, I'm a 360lb man trying to lose a lot of weight. Since I've upped my training program, I'll go upstairs to the indoor track at our gym, which is a soft surface, much like a normal track. I'll walk 2 laps, then do a dead on sprint for a lap, then repeat around 5x. Should I wait until I weigh less to run to avoid any knee problems or anything? Or is running OK, since I've did it for a couple of weeks already and not had any problems?