Hello, I'm a senior in college right now, and I've been running for what feels like my whole life. I've done 4 years of NCAA cross country and track, and I'm starting to give serious thought about what my fitness goals are going to be after I graduate. I really do love running, and would like to still be able to run long distances regularly, but for aesthetic reasons, I'd really like to gain some strength and muscle mass. How much would going from 6'0" and 140lbs to 160-175lbs affect my ability to run fast? I'm more or less satisfied with my PR's, so I don't need to be breaking 4 on the track post-collegiately, but I'd still like to be able to go on runs at a decent pace with friends. Has anyone else gone through this able to share their experience?