A primary reason individuals cite for not exercising regularly is being short on time. But high-intensity interval training (HIIT), characterized by workouts that tax the body with short periods of vigorous activity followed by brief periods of rest, are an effective way to burn fat, torch calories and get fit, according to findings from a number of studies.

Much of the research on HIIT has focused on aerobic exercise; as a result, the exercise program’s ability to help people quickly achieve cardiovascular health has been confirmed. But now, the results of a study conducted by the American Council on Exercise show that when applied to weight training, HIIT principles can also help individuals build muscle more rapidly.

But observe this key bit of advice from experts for safe cardio and weight training: Before working out, learn the proper techniques for all exercises and activities in order to avoid injuries.