I got out for a couple of runs with my sister while I was in NJ for her graduation. Unfortunately she wasn't up for trail running so we just did laps around the block. Not sure what my problem was, but both runs (especially the first) felt a lot harder than usual--maybe I got thrown off b/c I'm not used to running with anyone and went too fast. (She isn't used to running with other people either and said on the first run that I was throwing off her breathing rhythm b/c mine was so loud! However, her footsteps were MUCH louder than mine.)