Anybody mix heavy weight training and running? I've always been a pretty heavy lifter, but I've kind of fallen in love with trail running after adding it into my training program to train for these obstacle races that a group of us have been competing in, and I am planning on training for a marathon in the next year. Unfortunately, I'm having trouble maintaining 8-8.5 minute miles on the longer distances, and my legs seem to be pretty tired a lot of the time. Does this have more to do with overtraining, i.e. running too soon or too far after leg day, or more likely because I'm a bigger dude(6 foot and 210). I don't have a lot of body fat, but I'm wondering if I need to cut some weight and muscle to be a more effective distance runner. I don't see a lot of beefy dudes running long distances.