I have found that, at least for beginners, the planned, structured, short walks helps you a lot. It must obviously be trained as well and you must know yourself and your limits. Especially my wife benefits from this. If we go out to quick and without any structured (and stick to your times) walks she suffers, but if we do this she manages with the long ones much better. In fact we end the second half nice and strong. We do walk very fast as per norm and obviously train this even more. There was a LOT of times in Comrades where we walked behind bunches that tried to run (shuffle) inclines and we walked right behind them the whole way up. It is also planned around water tables where we normally have something to eat quickly as well etc, but we stick to the short allowed time of walking and then we go again. Same goes for later on if you get tired and have an unplanned walk, we try to adapt our walks/runs then with the unplanned ones to make up time again. All of this said, obviously the need for walks become less often and shorter as time goes on and fitness comes along!
