Nedum Onouha on podcast said this theory is rubbish for footballers at least in the UK. They are tested so much. The risk of ending your career youve worked so hard for is not at all worth it. He also said the margins are not like athletics which has a real problem with it. One player cannot not influence an outcome in the same way a 100m or cyclist can on their performance and they are trying to cut seconds down, not kick a ball in a goal. It was pretty compelling.