HIIT workouts are, for many, a quick and efficient way to fit exercise into your schedule. Most HIIT (that’s high-intensity interval training, for the uninitiated) routines focus on achieving optimum results in a short amount of time, and there are thousands who swear by the method. In fact, recent studies from the British Medical Journal found that the bursts of effort that HIIT requires could even be more effective for weight loss than longer steady-state exercise.