A high intensity interval is a portion of a cycle that is repeated when using the exercise method of high intensity interval training (HIIT). HIIT is a type of exercise training that is claimed to improve athletic conditioning and aid in weight loss in a shorter period of time than traditional, steady exercise. Using the HIIT method can be useful when trying to jump start weight loss or to break a plateau, as well as for improving overall athletic conditioning.
HIIT alternates a high intensity interval, or a period of very intense exertion, with a moderate or low intensity interval, a period of lower exertion. Typically, the high intensity interval lasts twice as long as the low intensity interval. This is known as the 2:1 ratio. For example, an athlete training with HIIT might pedal a stationary bike at maximum effort for 30 seconds, slow to a more comfortable pace for 15 seconds, and then repeat these steps several times to complete the workout. HIIT can be performed with many other types of exercises as well, including sprinting, swimming, jumping rope, or even boxing.
Generally, HIIT workouts take much less time to complete than traditional workouts because they are of a much higher intensity. An entire HIIT workout may consist of only ten repetitions of the cycle. If the above example of 30 second high intensity intervals and 15 second low intensity intervals is repeated ten times, the workout would last less than ten minutes. Contrary to the popular “longer is better” approach, HIIT manages to pack more effort into a much shorter duration.
Due to the very intense nature of HIIT, it is vital to perform a thorough warm-up before the workout and a long enough cool down afterward to avoid injury. Additionally, proper nutrition and a recovery period between HIIT workouts of 24 to 48 hours are necessary for the body to recuperate properly. HIIT may not be suitable for very sedentary people or for those with heart conditions or other health problems that could be aggravated by intense exercise.
For beginners or people not suited for high intensity exercise, less severe forms of interval training may be appropriate. Regular interval training still alternates a high intensity interval with a low intensity interval, but the durations are longer, closer to traditional exercises, and the effort expended can be much less extreme. For example, a person might jog for two minutes at a steady pace, and then walk for one minute.