Strength & other related exercises for runners

[Deleted User]

Hi all,

   Just been accepted to do the Thames Path 100 Hundred next year. So I have to go from being a semi serious Ultra runner to Ultra serious Ultra runner

Up until now I just go out and run. However I have managed to put together a pretty decent training schedule but I was wondering...............

How much difference would throwing in some strength  training help??

Anybody know of any training plans in that regard or youtube vid of a decent routine aimed at runners? Or is it a case of banging out squats and crunches and the likes?

Sorry for being so ignorant but I really hope to change it. Even to a point where I am dabbling with a bit of Yoga.....See I am serious