Hiit Workouts For The Treadmill

The acronym HIIT stands for high-intensity interval training, which is a type of cardio training that improves the maximum amount of oxygen you can take in during intense exercise, or VO2 max. This type of training improves your cardiovascular fitness as well. Researchers at Laval University in Quebec found that performing a HIIT program produces nine times more fat loss than an endurance training program in five fewer weeks. You can perform HIIT workouts on the treadmill by either using a timed ratio of work-to-rest or by using a heart rate monitor to identify your target heart rate for each interval.

Jogging Intervals

According to a study published in the December 2008 issue of "Applied Physiology, Nutrition and Metabolism," subjects who never did intervals previously increased their bodies' ability to burn fat and carbohydrates over 18 hours of HIIT workouts. The subjects performed 10 sets of four minutes of work at 90-percent effort followed by a two-minute recovery period three days a week.

Running Intervals

Perform five sets of two-minute running bouts with one minute of recovery between each interval for three weeks. Start at a running intensity of 90-percent effort and work up to 110-percent effort by the end of the third week. Researchers reported in the February 2010 issue of the "Journal of the International Society of Sports Nutrition" that performing increased intensities three days a week over a three-week period reduces body fat and increases VO2 max and anaerobic running performance.

Sprint Intervals

Japanese researchers found that you can improve your anerobic and aerobic capacities by a method known as Tabatas, named after one of the main researchers. The study used elite cyclists who performed six to seven 20-second bouts of cycling at 170-percent of their VO2 max, with only 10 seconds of rest.

This concept can be transferred to a treadmill by sprinting as fast as you can for 20 seconds, then hopping off the tread onto the side foot rails for 10 seconds and back onto the tread for six to seven intervals. Use caution when getting back on the treadmill.

Heart Rate

Sometimes timed intervals don't allow for enough recovery before starting your next jog, run or sprint. However, when you use a heart rate monitor, your body will tell you when you have recovered, and you can start your next work section of the interval.

A basic formula is to take 220 minus your age to determine your estimated MHR -- max heart rate. Multiply that number by 90 percent to determine your work intensity heart rate. Then, multiply your MHR by 60 percent minus your MHR for your recovery heart rate. For a more accurate method, use the Karvonen method: target heart rate = ((max heart rate - resting heart rate) --- percent intensity) + hear rate at rest.