Originally Posted by
The-Big-Gray-Man
I only do three runs a week and have found that it is enough to get myself very fit. Am definitely a believer in quality over quantity, at least in terms of your fitness.
I tend to do two short hard paced steep hill runs lasting about one hour which include twenty minutes of very hard paced climbing, to work my cardiovascular system to its maximum. With one longer glycogen building endurance run at the weekend between one and a half to two and a half hours long, which is run at a hard pace. I aim by the end of the runs to be totally spent and have nothing left to give. I don't really see the need to run more than three hours as once you have expended all your glycogen your body knows that it needs to adapt to store more and so no benefit can be derived from running beyond that.
Of course thats only talking about hill running from a fitness point of you.