High Intensity Interval Training (HIIT) has become one of the most popular ways to work out. There is a good reason for that: HIIT gets results.
HIIT encompasses a range of activities that involve short, sharp bursts of intense effort; typically 85-95 percent of your maximum heart rate. These are alternated with periods of low intensity activity or rest. High intensity intervals can range from 10 seconds to four minutes, with rest sections lasting anywhere from 30 seconds to four minutes.
For general health and fitness, HIIT offers a varied and efficient way to work out. An effective HIIT session can burn the same number of calories, or more, as moderate intensity continuous training (MICT) that might be twice as long in duration.
Why HIIT works
According to the British Journal of Sports Medicine, HIIT can produce similar, if not greater improvements in cardiorespiratory fitness to MICT.
When undertaking a HIIT workout, you condition your cardiovascular and respiratory systems to recover from high levels of physical stress, which leads to increased fitness.
While HIIT provides many of the same physiological changes as traditional endurance training, the reactions and processes it activates inside the body can be quite different. HIIT has a higher calorie-burning rate than MICT, with many studies also showing HIIT trains the body to burn more fat as fuel under a range of conditions; whether you are a beginner, or already in good shape.
Top Tips: Make HIIT work
Follow these tips to get the most out of your HIIT workout and recovery.
- Always take the time to warm up and cool down for high intensity training.
If you are just starting out, or your fitness has dropped off, take longer recovery periods between each bout of high intensity exercise. Start with a training-to-recovery ratio of 1:3 and build from there.
- If you are deconditioned, restore your fitness to a level where you can exercise continuously at a moderate intensity for at least 20 minutes, and continue for several sessions before progressing to HIIT.
- HIIT can be used to build strength-endurance by targeting large groups of muscles with exercises such as burpees, kettlebell swings, dumbbell snatches or medicine ball throws.
- There is no “ideal” interval length.
- Remember, intensity not duration, is the key. As you get fitter, push yourself harder in each interval rather than extending the duration of the interval.
- A sweet spot for endurance athletes is intervals of two minutes or more with an active rest. For example: run hard, then slow jog or walk.
- A typical HIIT workout, minus warm-up and cool-down, lasts 15 to 30 minutes.
- If you are under the weather or recovering from illness or injury, skip your HIIT session for a less intense workout.
Given the high intensity nature of HIIT, recovery is key. Do it right with these tips from the Australian Institute of Sport and you’ll be ready to fire at your next session.
- Sleep – The No.1 recovery strategy. Over time, lack of sleep can have a negative impact on performance, so make it a priority and have a good routine in place before bed.
- Compression – One of the best, and easiest, recovery methods to increase blood flow and reduce swelling and soreness associated with muscle damage and fatigue. The most effective garments for recovery are full length graduated tights, socks, long sleeve tops and arm sleeves as they cover your limbs.
- Hydrotherapy – Ideal for reducing fatigue, soreness and swelling. As a general guide, aim to accumulate five to 10 minutes in cold water (approximately 15°C) during a hydrotherapy session.
- Recovery boots/arms – Provide similar benefits to compression garments but apply a greater degree of compression to the limbs.
- Stretching – For recovery, the primary purpose of stretching is to relax the muscle. It can also help relieve heaviness and feelings of fatigue in the muscles.