Plodding away for hours on the treadmill is not the best way to burn calories. Instead, you can speed up your metabolism and shorten your workout with high intensity interval training, also known as HIIT.
Look at the benefits: Twenty minutes of high-intensity aerobic exercise can boost your VO2 max as well as burn more calories, raise your metabolism and preserve your muscle tissue, all at the same time. On the other hand, too many long, slow cardio sessions may actually have a negative effect on your physique because the body breaks down muscle for energy.
The key to HIIT is to do it right and use it sparingly–no more than twice per week. Continue with longer sessions as well, alternating between steady-state cardio and shorter interval-training sessions. You can apply the guidelines in the chart below to any aerobic activity you please. In fact, changing your mode of exercise every time you do cardio could provide you better results.
Intervals can be done in different ways, so don’t feel like you have to limit yourself to the machines at the gym. Run laps at a local track, go for a bike ride or grab a jump rope! Not only will intervals allow you to train harder and burn more calories, but you’ll also challenge yourself and ditch the boredom of yet another session of steady-state cardio training.