So I recently paid for a local coach who people have been swearing by. He has coached many 22min+ 5Kers to 17min 5Kers in less than a year. He believes in a lot of mileage but he will not let anyone run over 60 minutes (he only coaches guys so far). He says it lowers testosterone. So there are a lot of doubles involved. What are people's thoughts on never running over 60 minutes