One of the most commonly cited reasons for not keeping physically active is just not having time. If this doesn’t apply to you, congrats! You’ve beaten one massive hurdle to regular physical activity. If it does, scientists have thoroughly investigated a style of exercise called high-intensity interval training, or H.I.I.T. (pronounced “hit”), which involves short intervals of all-out, maximum effort exercise flanked by longer bouts of lower intensity exercise. For example, a H.I.I.T workout could be repeated intervals of cycling as fast and as powerfully as possible for 20 seconds, then cycling at a slow, relaxed pace for 60 seconds until you’ve cycled for a total of 15-20 minutes. These workouts come in many forms (find free full H.I.I.T. workouts here) and can last minutes to hours, but if you truly give your all during the high-intensity portions, you likely [...]