HIIT, or high intensity interval training, is a cardiovascular exercise technique incorporating periods of low intensity work alternated with periods of near maximum intensity. HIIT helps improve your maximum oxygen intake capacity, or VO2max, thus enhancing your overall endurance. This type of training also increases the body's ability to oxidize fats, according to a study published in the December 2008 issue of Applied Physiology, Nutrition and Metabolism. You can achieve all the benefits of a HIIT session in as few as 20 minutes if you are willing to exercise beyond your comfort zone.
Warm up on the treadmill for 10 minutes. Walk or jog at a very slow pace to encourage blood flow to your muscles and get your body ready for higher intensity activity.
Increase your speed to a very fast pace for 30 seconds. You should not be able to talk.
Reduce your speed to a light jog or fast-paced walk for two minutes. Make your recovery time equal to three to five times the duration of your high-intensity segment. If you really push your effort during the high intensity drills, you will most likely need to walk.
Alternate the high intensity segments with low intensity segments for 20 to 30 minutes.
Incorporate HIIT two times per week on non-consecutive days. Allow your muscles to rest at least 48 hours between sessions so they can repair and grow stronger.