Few exercise techniques are more effective at improving fitness rapidly than high-intensity interval training (HIIT)— a series of brief, high-intensity exercise sessions interspersed with short rest periods. The four components of interval training include distance, repetition, intensity and rest, defined as follows:
1. Distance refers to either the distance or time of the exercise interval.
2. Repetition refers to the number of times repeating the exercise.
3. Intensity refers to the speed of performing the exercise.
4. Rest refers to the time spent recovering between exercises.
Canadian researchers determined that six sessions of high-intensity interval training on a stationary bike increased muscle oxidative capacity by almost 50 percent, muscle glycogen by 20 percent and cycle endurance capacity by 100 percent. The subjects made these remarkable improvements by exercising only 15 minutes in two weeks. Each workout consisted of four to seven repetitions of high-intensity exercise (each repetition consisted of 30 seconds at near-maximum effort) on a stationary bike. Follow-up studies showed that practicing HIIT three times weekly for six weeks improved endurance and aerobic capacity as well as training five times a week for 60 minutes for six weeks. These studies and many others showed the value of high-intensity training to build aerobic capacity and endurance. (ACSM’s Health & Fitness Journal, 19(6): 3-6, 2015)