Weight does factor in long distance running. But so does experience. I would say all runners can benefit from lifting. How much should they lift? If they are only lifting 95lbs on say on squats that will translate to a lot of punishment while running. A runner should be able to maintain or get better at running when gaining strength. The amount gained won’t be a 400 lb squat. Maybe something like 225 for 3 sets of 5 reps. Body weight may go up 5 lbs. the increased muscle will help the body take the daily running grind. And like all things you will have to figure out the programming and what emphasis goes where and when. Rippetoe’s right. Gain strength, it’s just a matter of how much to gain for running.
