For those who don’t want to do more, but really want to do less, Wisløff and others have shown that even shorter, less structured workouts are still remarkably beneficial. High-intensity interval training (HIIT) is a very short workout—thirty seconds to a minute of running, climbing stairs, or cycling—followed by a minute or two of cool-down activities, such as walking or slow pedaling. Repeat the cycle for only ten minutes and you’ve just done a HIIT. “While anything helps, a bit more is probably better,” University of Michigan researcher Weiyun Chen commented.
