HIIT involves short bursts of intense exercise alternated with low-intensity recovery periods. Interestingly, it is perhaps the most time-efficient way to exercise.
Typically, a HIIT workout will be 10–30 minutes in duration. Besides being a shorter regimen than you'd find with most continuous movements, aerobic high-intensity interval training, or HIIT, allows you to raise your heart rate higher, and burn more calories, than you could with steady-state exercise.

-HIIT promotes better blood sugar regulation: Physical activity causes your body to demand glucose for energy.

- HIIT improves blood vessel function: As we age, endothelial dysfunction (an imbalance in the substances that make the lining of the blood vessels dilate and constrict) tends to occur and is linked to elevated blood pressure and increased risk of heart attacks. Adding HIIT might help offset some of these natural changes.

- HIIT can provide more enjoyment than other forms of exercise: HIIT workouts practically appeal to people because they're efficient and effective. But that's not the only reason for their popularity.

-HIIT can improve oxygen consumption.