High-intensity exercise and your heart

High-intensity interval training (HIIT) may improve fitness faster because people exercise harder rather than longer. HIIT features short bursts of high-intensity exercise (usually lasting one to four minutes) interspersed with periods of lower-intensity activity or rest. People who are older or who have heart disease should check with their doctors before trying HIIT. HIIT may produce equal or greater improvements in blood pressure and blood sugar compared with moderate-intensity exercise. But in terms of longevity, both exercise strategies seem to be equally beneficial.