Has anybody adopted high-intensity interval training? When I was younger, I used to go to the gym all the time and put in a 60 - 90 minute workout. Then life got in the way and I got lazy and fell out of it. Over the last year, I finally got fed up with the way I felt and looked and started HIIT training, along with mountain biking, and intermittent fasting. It has worked wonders for me. I'm sprinting using the Peak Fitness Method, which is 30 seconds of maximum effort followed by 90 seconds of recuperation for 8 repetitions. I have also used the same method when biking just using longer intervals and longer distances. Anybody else doing HIIT?