Bella Adams
High-intensity interval training – HIIT for short – pushes you to your physical limits and melts away excess fat. How the training affects your body and what exercises you can do at home.
Are you constantly running your park laps or even on the treadmill, but somehow your body hardly changes? Or you do your bodyweight training several times a week, but just don’t feel any progress in terms of strength and endurance?
Time to integrate High-Intensity Training – HIT or HIIT (High-Intensity Interval Training) – into your workout routine.
This high-intensity training method has been at the forefront of fitness trends for years.
A study by ACSM’s Health & Fitness Journal of more than 100,000 fitness and health industry experts worldwide confirms this.
How does HIIT work?
In the HIIT training method, a high-intensity active slot always alternates with moderate phases or active breaks.
This means, for example, sprinting as a power interval and walking as an active relaxation time. An interval refers to a unit of exertion plus a minimal rest for recovery so that the load remains high throughout.
The high intensity refers to the heart rate: This should be 85 to 100 percent of the maximum heart rate during the load phase.
During the relaxation period, the heart rate may then drop to 40 to 50 percent of your maximum heart rate.
You can do this power training concept virtually anywhere and in many sports: jogging, weight training at the gym, or at home.
How does a HIIT workout work?
HIIT workouts can last between four and 45 minutes. There are no rigid rules on how long the intervals have to be. Common:
- a load of 15 to 60 seconds and
- an active rest phase of 10 to 30 seconds (approx. half of the active time).
It’s important to rest only until you feel up to the upcoming load again – no longer. Go to your limits in the specific load phase, so give it a good throttle and don’t do anything halfway.
Tabata is a special form of HIIT training. With Tabata, you only train for four minutes – in eight intervals, each with a load of 20 seconds and a break of 10 seconds. You can incorporate this workout into your training routine more often.
It doesn’t matter if it’s four or forty minutes: Interval training boosts fat metabolism – even for several hours after the workout – and improves your strength endurance, trains the cardiovascular system, and increases maximum oxygen uptake.
How often should I do HIIT?
It is important that you give your body enough time to recover – High-Intensity Interval Training is not a training method that is suitable for every day.
Compared to a training plan with longer workouts at moderate intensity, HIIT achieves faster results, but also requires more recovery.
Because of the high load, experts recommend training no more frequently than two to three times a week for 15 to 30 minutes according to the HIIT principle.
The “a lot helps a lot” mindset can cause a real HIIT burnout, the typical overtraining.
Permanent exhaustion, sleep and concentration problems without obvious causes can be an indicator that your body needs a regeneration phase.
In that case, reduce the HIIT portions for a while and allow yourself and your body more time for moderate and regenerating activities.
“HIIT makes us more muscular, stronger, and faster, but it also makes us age faster,” says Michol Dalcourt of the California Institute of Exercise.
Stress stimuli in the cells and the associated increased production of the hormone cortisol, which makes it harder to burn fat, especially on the abdomen, are to blame.
What are the effects of interval training?
Completed at regular intervals and with sufficient regeneration phases in between, HIIT combines many positive effects of other sports:
- Maximization of fat burning
- Increase endurance
- Building muscle mass when doing strength exercises
HIIT burns significantly more body fat than moderate fitness training in the same amount of time.
The exercises push your body to its limits, where it uses above-average amounts of oxygen. In this way, the metabolism is vigorously stimulated.
So if you prefer shorter workouts and are ready to go full throttle, you’ve come to the right place.
If you prefer a more moderate workout, but jog or exercise for an hour, you don’t have to do HIIT to burn a lot of fat.
And what is it about the afterburn effect?
To get back to normal after HIIT, your body has to expend extra energy – this is called the afterburn effect. What does this mean in concrete terms?
Even hours after the strenuous interval training, your energy metabolism is still increased – and this afterburn effect lasts 24 to 72 hours after the load phase, depending on the intensity of the intervals. This has a positive effect on body fat percentage in the medium term.
However, a 2017 analysis by scientists at the University of New South Wales found that moderate and intense workouts did not differ in their effect on fat burning.
Both achieved the same results in the test subjects: The advantage of HIIT is merely the time saving of around 40 percent.
The effects of HIIT on endurance and muscle mass
There are several studies that have examined the success of High-Intensity Interval Training with regard to stamina.
The result: if completed regularly, the method improves endurance three to four times faster on average than, for example, ordinary, moderate running training.
Those who want to work less on their fitness but build up muscle mass can also rely on HIIT.
According to a study, interval training increases the release of the growth hormone HGH, which plays a key role in muscle growth.
HIIT is even considered the best method to increase growth hormone levels.
In addition, HIIT is said to dampen hunger pangs, reduce mood lows and stress, and help with high blood pressure and arteriosclerosis.
The best HIIT exercises
The intensive training program can be transferred to almost any sport and can be completed quite easily at home.
For runners: The simplest basic exercise is alternating between sprinting and walking. You can also do this on a treadmill, no problem. The same applies to cycling or rowing.
For bodyweight training, exercises like jumping jacks, crunches, squats, lunges, or push-ups are good. You can also work with dumbbells or barbells.
