In the Easton, MD area there are many runners. I’ve done many training sessions with people that run marathons or just run for fun. Each one has expressed improving their running times and ease to maintaining pace due to strength training and agility training.
A few of the training techniques I use are squats immediately followed with sprints, Romanian deadlifts followed by jump squats, agility drills incorporating fast feet linear, vertically and horizontally, TRX movements and broad jumps. We also train chest, back, shoulders and arms and lots of upper and lower abs and lower back.
I also like to make them elevate their heart rate for bursts of 30-60 seconds and then let recover. This helps teach the runners how to deal with breathing under stress. Many have never or will not push themselves to do this with out big brother watching. We also stress when becoming fatigued while doing a movement they must focus on form and technique to develop the ability to finish and not fall victim to sloppy form.