If strength training is to be beneficial alongside high mileage or very demanding runing programmes, I have come to the conclusion (all be it a little against the grain) that you simple cannot strength train conventially, i.e 2 sets to failure. I am convinced that the key is to work with very heavy sets of between 2-5 rep max. However and here is the unconvential part, don't go to failure, finish the set before this. This way you still get the neuromuscular stimulus without the massive fatigue hangover that eats into good running training.
What do you think and what experiences have you got of this?