Less than half of all adults in the U.S. get the recommended physical activity each week. Regular physical activity reduces the risk of many diseases and increases life expectancy.

An effective method of enhancing physical performance, over traditional endurance-based training, is through high intensity interval training (HIIT). It's a cardio respiratory training technique that involves repeated periods of high intensity effort followed by either a low intensity period or complete rest. This concept is becoming increasingly popular among athletes and recreational exercisers alike.

Most endurance workouts, such as walking, running, or stair climbing, are performed at a moderate intensity, or an exertion level of about five to six on a scale of zero to 10. High intensity intervals, however, are typically done at an exertion level of seven or higher but last for shorter periods of time (typically a few seconds to several minutes).

Total workout time can range from four to 30 minutes, and can be done in a variety of settings such as exercise machines with variable speeds and resistance, group fitness classes, outdoor running, and even resistance training.

Benefits of HIIT can include: improved heart and lung function; enhanced metabolic function (how well the body creates and uses energy); increased metabolic rate; increased maximal oxygen consumption; improved blood pressure and cholesterol; and reduced subcutaneous body fat (the fat under the skin, such as around the abdomen and thighs).

Elite athletes and sedentary individuals alike have benefited from HIIT. However, those who aren't currently exercising should consult their doctor and obtain medical clearance prior to engaging in HIIT. Recommended guidelines include exercising within one's own capabilities, allowing adequate rest between exercises and workout sessions, and maintaining proper form for all exercises. For best results, add one or two sessions per week to regular exercise routines and work towards a balance of HIIT with continuous aerobic exercise.

May is National Physical Fitness and Sports Month, a great time to renew one's commitment to a healthy, active lifestyle and to spread the word about the benefits of physical fitness. Contact the command fitness leader, Wellness Center or Health Promotions office, or visit the Navy and Marine Corps Public Health Center's website for more information.

NH Jacksonville's priority since its founding in 1941 is to heal the nation's heroes and their families. The command is comprised of the Navy's third largest hospital and five branch health clinics across Florida and Georgia. There are 71,000 active and retired Sailors, Soldiers, Marines, Airmen, Guardsmen and their families enrolled with a primary care manager and Medical Home Port team at one of its facilities. To find out more, visit the command website at www.med.navy.mil/sites/navalhospitaljax.

For more news from Naval Hospital Jacksonville, visit www.navy.mil/.