Originally Posted by harvey

See, the thing is that every body, every condition, every health is completely different. As an example, I exercise 4-5 times a week, and I do 15-20 minutes bike every day.... yet I wouldn't be able to run the distance you want to run. One of the reasons is I'm pretty muscled (hence heavy) and I was a basketball player, hence my ankles are shit. Plus, I smoke 12-16 cigs a day. Thus, I run 200-300 meters and I have to slow down. After 20 mins of jog/walk/jog/walk I cover around 5km and I feel a step closer to sudden death