My read on it is that it reduces the amount of engagement required by various muscles and particularly feet. It makes running a lower impact exercise, closer to

My read on it is that it reduces the amount of engagement required by various muscles and particularly feet. It makes running a lower impact exercise, closer to cycling. This is great for training VO2 max but we mustn’t forget that one of great things about running is that it trains all sorts of small support muscles, particularly in feet and lower legs.