Question: are 15 minute hiit workouts effective?
Answer: Well, the NHS says that in order to stay healthy, adults aged between 19 and 64 should do at least 150 minutes of moderate - or 75 minutes of vigorous - aerobic activity and strength training a week. ... Vigorous means high-intensity training (HIIT) - meaning that 15 minutes a day works, but only if you're going hard.