I have been running for 15 years and I'm an endurance athlete also so I know where you're coming from. don't do aas right now. doesn't do crap for a real endurance athlete where you're at. If you were in a place where you could run a pre-season strength cycle then I would reccomend t bol and var with test as a base. However I have heard good things about s4 increasing endurance to a certain extent. EPO could be an option for you if you know what you're doing but it's dangerous. You won't find much talk about epo or distance running on this forum though.