High Intensity Interval Training or HIIT, which is sometimes known as Tabata after a very popular and specific form of this type of exercise, is exploding in popularity.
This type of workout has a lot of different benefits. HIIT not only promises the benefits of cardio without the stupefying boredom and the large investment of time, but it can also be designed to incorporate strength and performance exercises, allowing you to work on your weak points and get faster and stronger while you improve fitness. The biggest drawcard for a lot of people is the remarkable ability of an HIIT workout to burn fat. Not only is fat burnt during the workout, but HIIT can heighten the body's ability to burn fat for the next 24 hours. Research has shown that regular HIIT causes the body to adapt to burning more fat as a fuel source (1).
Both men and women have been streamlining their workouts and getting great results using HIIT, but this form of training is no walk in the park. (It's actually more of a jog which is constantly being interrupted by burpees and jumping jacks, which ends in near-leg failure, but hey! the park is a great place to train!)
Watch Our HIIT Workout Video Featuring Two Expert HIIT Trainers
Here are our top five tips for getting the most out of your HIIT workout.
1. Start slowly
HIIT is often referred to as the fifteen minute workout, and this can give a misleading impression of its simplicity. HIIT may be simple to fit into a schedule, but it is a seriously difficult workout, and it's no good for beginners or for the fainthearted. A good level of baseline cardio fitness is essential to keep up, and a good guideline is to hold off on the HIIT until you are comfortable jogging 30 minutes non-stop, and do this at least three times a week.
Once you've got your baseline fitness, there are a couple of ways to ramp up your workout.
The gradual way involves addding intervals to your existing cardio program. Someone who jogs for 30 minutes a day might start by adding some basic intervals – try 30 seconds of sprinting every five to ten minutes. The ratio of sprints to intervals can be increased as fitness levels increase, upping the intensity and shortening the duration of the jogging, which becomes the recovery period.
The second, braver way involves jumping straight into an HIIT program at full intensity, but starting with a shorter duration. A normal HIIT workout lasts for about 15 minutes, so a good first effort might be half as long. Keep the pressure yourself and on and aim to get to the full workout as soon as you feel able. Make up the extra time with standard cardio until you get there.
2. Warm up
It may sound obvious, but this is one type of workout where you really don't want to skip your warm up. Whether you're doing sprint intervals, burpees, squat-throws or jumping lunges, a lot of common HIIT intervals are designed to use as many muscles as possible to maximise conditioning and fat burning, and you are ideally working them to maximum capacity. Fatigue and overuse greatly increase the potential for injury. Make sure you do at least five minutes of slow cardio, and warm up every muscle you plan to use in your session.
3. Interval Training vs HIIT vs SMIT
Are you getting the most out of your workout? You might not be if you're not doing the type of training that you think you're doing. HIIT sits in the middle of a continuum, with normal interval training on one side, and Supra Maximal Interval Training (SMIT) on the other. These are all interval based modes of training, and deliver varying benefits.
Interval training is the closest of these three to regular cardio, and involves alternating between a baseline cardio activity and a more intense interval, generally at 60-70% of VO2 Max. The classic example of interval training is a jog with hill climbs. The change between base and interval is less dramatic that HIIT, and the interval less intense. Interval training is great for improving endurance, but is closer to regular cardio in terms of fat burning benefits and workout length.
While trainers should aim for 90-100% of VO2 Max during intervals in an HIIT workout, SMIT takes this even further, into the anaerobic realm, with intervals that hit as much as 180% of VO2 Max. These alternate with complete rest, as opposed to the low intensity exercise periods in HIIT.
SMIT is fantastic for increasing power and endurance in athletes, but this anaerobic workout is not particularly effective for burning fat because fat metabolism is fuelled by oxygen.
The best way to control your output and keep on track is by monitoring your heart rate. Find out your VO2 Max (there are many ways to do this) and keep checking to make sure your heart rate is staying within the 90-100% zone during intervals. The easiest way to do this is with a portible heart rate monitor with an audible alarm, or by training on gym equipment with a built in monitor. If none of these are available the old fashioned way is better than nothing. If you are unable to take your pulse during an interval, take it immediately after.
4. Don't replace all your training with HIIT
There are a few good reasons for this. Firstly, HIIT is a high stress exercise which takes a toll on your body, and a proper recovery between sessions is essential. A good way to do this is by alternating workouts. HIIT also carries a high risk of injury, which is only increased by a poor recovery.
It is quite easy to incorporate exercises into HIIT that rely on strength, but you're not going to get the same level of strength training that you would in a separate workout. Not only does weight training give definition and tone, but it builds muscle, which burns a lot more energy than fat. Because strength training keeps the metabolism up, it makes cardio-based exercised like HIIT more effective in the long run.
Finally, doing the same type of workout day in, day out, is boring. Mixing it up can keep things interesting.
5. Pre-plan your workouts
An easy day of cardio is great when you have sore muscles and want a rest, but HIIT is not like normal cardio - if you're doing it right, it should give you sore muscles! This means you're going to have to put a little more work into planning your schedule. Take the obvious into account, for example, don't plan to work out legs the day after you've done sprint intervals, and vice versa. As you develop your fitness and repertoire of intervals, you'll gain an understanding of what works best.
Check Out Fitness Professional Jason Haywood's HIIT Workout
(1) Perry CG, Heigenhauser GJ, Bonen A, Spriet LL. High-intensity aerobic interval training increases fat and carbohydrate metabolic capacities in human skeletal muscle. Appl Physiol Nutr Metab. 2008 Dec;33(6):1112-23.