High-intensity interval training alternates challenging work periods with short recovery periods. Intervals can be adapted for beginners, performed without equipment and fitted into a busy schedule.
Reported benefits include efficient calorie use, improved endurance and oxygen consumption, reduced heart rate and blood pressure, and better blood-sugar control. Some people may also gain muscle when HIIT is combined with strength work.
Start with an appropriate intensity and allow recovery between sessions. HIIT is demanding; more sessions are not automatically better, especially for beginners or anyone managing a medical condition.