It's really weird. In 400s, I have no trouble leading and I'm usually ~4-5 seconds ahead of the next person on those. On long runs, I usually start off with a group of 2-3 guys and then pick it up on the second half. But when I run long runs alone, running just feels super tough. I don't know if it's because I don't have those guys to distract me or what, but I feel like I'm trying much harder to run a similar pace. Any suggestions? Does this happen to anybody?