No matter what your fitness level, you can increase the intensity of your workouts using HIIT. This type of training cycles between quick, intense bursts of exercise and moderate/low exercise. This cycle repeats throughout the workout. It burns more calories than traditional workouts, so you can work out more quickly and more efficiently.

HIIT is not just for advanced athletes--you can modify it to fit your age and fitness level. Let's say you walk for 30 minutes a day and you don't have time to walk longer but you still want to improve your fitness. Try walking a little faster for one minute and a little slower for two minutes, and repeat that for the entire 30 minutes! If you are more advanced, you can try a DVD HIIT workout like Crunch Live and Cardio Dance HIIT, available at the library. Other popular HIIT workouts include Insanity as well as Tabata and TurboKick. For more information and how-to guides, check out the books and DVDs below!

Guest post by Safiah Hassan. She is a student at Vanderbilt University receiving her Master's Degree in Medicine, Health, and Society and she enjoys doing HIIT in her workouts!