Below is a good read on what endurance athletes need to be looking at when talking strength training. HOWEVER, this type of lifting is hard and has a technical component that MOST have never learned. But when you add this to your training, you will go faster. Coaching elite athletes everyday, I incorporate speed and power work weekly. It's a must to improve. We don't stop in season, we keep it as I view it as fundamental .
a good coach knows how to teach athletes how to use what was learned and applied in the strength exercise in how to use that in running. I have seen direct connections from the strength in the weight room to distance running... But you need a good coach to know how to teach it and transfer it to running.
its a process but again it isn't a process. If you wait to progress it, the understanding is lost. You progress it together, you don't develop a hanger, progress them tomorrow. Transfer and load.