High-Intensity Interval Training (HIIT), also called High-Intensity Intermittent Exercise (HIIE) or Sprint Interval Training (SIT), is a workout technique that alternates high intensity phases and active recovery phases.
The goal of this technique is to increase the athlete’s performance without necessarily exercising for long durations.
There are a lot of sports where HIIT can be applied easily and achieve great performance. This includes running, biking (spinning bike), in-line skates, boxing (the bag), and squats are great examples, just to mention few.
There are several variations of HIIT. The workout sessions are quite short and last between 9 and 20 minutes. The original protocol provides a 2: 1 ratio between periods of workout and recovery. For instance, while running, we can alternate 20 seconds of sprinting followed by 10 seconds of recovery (walking or running slowly.)
Benefits of HIIT
Several research experiments have demonstrated the effectiveness of the HIIT method compared to traditional training programs in endurance. A study conducted at the National Institute of Fitness and Sports in Japan showed that 2.5 hours of HIIT produced biochemical changes in the muscle and performance similar to 10h30 working endurance. During this study, they conducted two training experiments using an ergometer. They measured the training benefits on anaerobic capacity and VO2 max, endurance by medium intensity intermittent work and high intensity.
First, they evaluated 6 weeks training effect in moderate endurance (70% VO2 max / 60mn day / 5 times per week) on the anaerobic lactic system and VO2 max. After training, the anaerobic capacity was not increased significantly, while the VO2 max increased to 5-ml.kg 1.mn-1.
Secondly, to quantify the effect of the intermittent intensive training, seven subjects were trained 5 times per week during 6 weeks. The training consisted of 7-8 repetitions of 20 seconds of work at 170% VO2 max and 10 second cooldown. After this training period, VO2 max increased 7 ml.kg-1.mn-1, while anaerobic capacity was increased by 28%.
In another another study, Jeffrey W. King made a comparison of the effects of Interval Training vs. Continuous Training on Weight Loss and Body Composition in Obese Pre-Menopausal Women. The study showed that the HIIT technique provides better results than the continuous training technique. The study has also shown that HIIT increased more significantly VO2 max than a long endurance training.
HIIT and Weight Loss
Professional trainers increasingly offer HIIT workouts, especially to beginners who want to slim down. A HIIT session, like any good split session, helps to increase the basal metabolic rate 24 hours after the session. That explains its ability to promote the loss of body fat.
If you are not athletic, we strongly advise you not to start with a HIIT session without consulting a doctor first.
Obviously, when aiming to lose weight, you have to combine training with a low calorie diet. If you do HIIT trainings, don’t forget to also adjust your nutrition diet to recover faster.
The Various Protocols of HIIT
The Tabata method
Tabata is the name of a Japanese researcher (cited above) who discovered a way to improve both anaerobic and aerobic pathways. Hi method is quite simple – choose an exercise and do it as follows:
- For 20 seconds, do as many repetitions as possible
- Rest for 10 seconds
- Repeat 7 again
In total you will make 8 sets of max possible repetitions, followed by 10 seconds of rest brief – simple and effective.
It’s recommended to do 2 to 4 sessions per week. This program is perfect for people who are very fit and don’t have a lot of time.
Of course, you can work more than 4 minutes. With a little practice you can quickly make 20-minute programs.
Little method is another way to train using a training time of 60 seconds followed by 75 seconds of rest, repeated 8 or 12 times. Even simple bike is enough to easily apply this method.
Note that, since the training time is longer, the intensity should be significantly lower than the Tabata method (170% against 95% of VO2 max).
A general physical preparation session can be as fellow:
After a 15 minute warm-up:
- 8 times: 20 sec max pulls / 10 sec recup
- 8 intervals 20/10: Pump max
- 8 intervals 20/10: max abs
- 8 intervals 20/10: max squats to body weight
It is recommended to do this training 3 times per week.
This training is perfect for those who want to incorporate strength training into HIIT. It consists of weight/strength training combined with hi intensity cardio.
After 5 minute warm-up, do 8-rep set of weighting, followed by 1 minute of cardio (e.g., mountain climbers). Then repeat this combination for a full-body routine for 45 minutes.
HIIT is a very efficient workout technique with a lot of benefits. In addition to its efficiency, it’s also very simple to do and doesn’t require a lot of time and effort. In addition, it can be done anywhere by simply mixing different kinds of training. You can do the split running, rope skipping, the raised land, plyometric jumps on a bench, etc.