High-intensity interval training (HIIT) is a form of interval training alternating short periods of intense anaerobic exercise with lower intensity recovery periods.
A person would perform a short burst of high-intensity exercise followed by a brief lower intensity activity, repeated until fatigue. The high intensity sections are at near maximal effort. The ratio of work to rest is usually around 2:1 so if 30 seconds of work is performed, then 15 seconds of rest would be between.
Because they are such a high intensity level, the workouts really maximize time with workouts rarely lasting longer than 20-30 minutes, and sometimes as little as 4 minutes.
Benefits
Studies have shown that HIIT training is MORE successful in improving cardiovascular fitness and VO2 max than moderate intensity continuous training,
Compared to regular cardio HIIT produces a greater calorie burn (or EPOC—excess post-exercise oxygen consumption) that’s maintained after the workout is over – so you burn as many or more calories overall, even though you only train for a shorter time.
Of course another huge benefit is that if you have limited time available, high intensity training can significantly reduce the amount of time you need to dedicate to training. Squeeze in a quick 15 minute session on your lunch break, and you still have time to shower and eat lunch after.
Example HIIT session
You can really use any exercise you like for the intervals, as long as you can work at a very high intensity for a short time, things like plyometrics and bodyweight exercises can be some of the best choices, as they don’t require setting up equipment or adjusting anything. The following is an example of a circuit style HIIT session, performed on suspension trainers like a TRX.
30 seconds work, 15 seconds rest – 3 times through (under 15 minutes)
- 1 leg squats
- TRX Push ups
- Skipping
- TRX Rows
- Burpees