I'm not sure if this is the right place to post this but I couldn't find any other subreddit for it. This has been happening for as long as I can remember, but I only recently thought of asking about it. My friend and I were rushing to catch a bus because we were running late for training. I got there a couple of minutes earlier a month later we were late again and we ran for the bus. This time my friend got there about 15 seconds before me. I want to clarify that it's not a stamina issue. The problem is that I can’t physically sprint as fast as my friend the second time. I was not tired from running in either case. If anyone has a clue why this happens, please let me know.