The fitness industry is currently experiencing a surge of interest and growth in high intensity interval training (HIIT). This method of training involves repeated bouts of high intensity efforts that range from 5 seconds to 8 minutes followed by recovery periods of varying lengths of time. Billat (2001) points out that as early as 1912 Hannes Kolehmainen, famous Finish Olympic long-distance runner, was employing interval training in his workouts. As the knowledge of HIIT increased, exercise scientists demonstrated that this type of exercise not only provides performance benefits for athletes and improves the health of recreational exercisers, but it may also be a suitable alternative to endurance training, or continuous aerobic exercise.
Another metabolic benefit of HIIT training is the increase in post-exercise energy expenditure referred to as Excess Post-exercise Oxygen Consumption (E.P.O.C.). Following an exercise session, oxygen consumption (and thus caloric expenditure) remains elevated as the working muscle cells restore physiological and metabolic factors in the cell to pre-exercise levels. This translates into higher and longer post-exercise caloric expenditure.
The major goals of most endurance exercise programs are to improve cardiovascular, metabolic, and skeletal muscle function in the body. For years continuous aerobic exercise has been the chosen method to achieve these goals. However, research shows that HIIT leads to similar and in some cases better improvements in shorter periods of time with some physiological markers. Incorporating HIIT (at the appropriate level of intensity and frequency) into a client’s cardiovascular training allows exercise enthusiasts to reach their goals in a very time efficient manner.
Example HIIT workout
Warm-up: Light 10-min run around track.
Interval: 800-meter runs at approximately 90% of maximal heart rate (based on estimation heart rate max = 220-age). Each 800-meter interval should be timed.
Rest Interval: Light jog or walk for same amount of time it took to run each 800m
Work/Rest ratio: 1 to 1 ratio. The time for the interval (800m) and rest interval should be the same.
Frequency: Try to complete 4 repetitions of this sequence.
Cool Down: 10-min easy jog.
Comments: The distance of the interval can be adjusted from 200 meter to 1000 meter. Also, the length of the rest interval can be adjusted.
Adapted from Musa et al. (2009)
Lunch: home made humous and crackers, apple
Dinner: sausage and kumara, hot cross bun
Exercise: 50 min bike ride (windy!)