I've heard that strenght must come first, and everything else follows. Will working pure strength on the legs(pistols or heavy squats) help with endurance for running long distances, like more than one mile, or lets say up to 10 miles? Will it be comparable to someone who's in the military?
@shon, I don't think there's a one-size-fits-all answer to the question you've asked.
We have stories of world-class distance runners who cannot do a single pullup - would a little more upper body strength help those people? I think so.
The way distance runners often go about improving leg strength is sprinting - this has been what I've seen, namely that sprinters lift weights, and distance runners sprint. Would pure leg strength help a long distance runner? I think that will vary by the individual - for some, I think it will, but improving leg strength in someone who uses their legs in their sport is likely best accomplished by in-sport training, e.g., running some faster paces over shorter-than-race distances. But OTOH, if someone's endurance running shows signs of weakness, perhaps frequent injury or deterioration of form late in a race, then perhaps some leg strength training would help. In the end, it's a question for the athlete's coach. And if the athlete in question isn't coached, is trying out for the military, or just generally doesn't have a high running standard to meet, then I think some experimentation is in order.
The biggest concern about leg strength training for distance runners, IMHO, would be avoiding having the training tire their legs - if their running suffers as a result of their leg training, then it really can't be included except in an off-season program when they're not running much.
In short, there are too many variables to answer this question in a general way, IMHO.
-S-