Exercise smart, not hard. It’s not about working out for longer periods of time but rather working harder in your limited time that gives you the desired result. Alternating periods of intense effort with periods of moderate-to-low effort in one single session during your physical work out is called Interval Training. Studies have shown that interval training helps burn more calories, increases cardiovascular fitness and increases metabolic rate. For people who are trying to control their blood sugar adopting interval training practice helps a lot. So if you regularly walk, the best way to adopt this practice it to include a few minutes of jogging into your brisk walks. You could also alternate leisure walking with intervals of fast walking. The key to make interval training work is intensity. After each interval of intense activity you must slow down and let your heart rate come back down.
Read here for more details on the experiment conducted in this regard.