HIIT is high intensity interval training….on the Pelaton bike it means you work so hard as to raise to your maximum heart rate (by age) and become breathless (just about) for “seconds” not minutes…in intervals. My workouts involve a total of 15 mins 5x week of HIIT that is 3 sets of 30 seconds, 5 x 20 seconds, 5x 10 seconds…each set has a recover in between set of seconds, 30, 20, 10 respectively. You raise your heart rate to at least 75-85 % of maximum for your age. It has increased my lung capacity and decreased my wheezing. Not easy task but for me worth it.
Regina