HIIT – the promises and pitfalls of the ultimate fat-killing method

If you are seriously involved with bodybuilding, fitness or any related sport chances are you have either tried HIIT method or you are planning to.

The number of existing successful scientific studies is so persuasive and anecdotal evidence so overwhelming that it seems there is no reason not to apply HIIT any time you seek to cut fat.

However, the reality is – as always – much more complex. HIIT is not suitable for every situation, for every training aim and indeed – it’s not for every one.

What is HIIT

HIIT is short for High-Intensity Interval Training. Historically there were several training methods that gradually led to the evolution towards HIIT – various kinds of interval training and short high-intensity workouts.

By definition, HIIT is a combination of short bouts of maximum-effort exercising and longer moderate-effort exercising (imagine sprinting and walking back, this repeated several times).

The best known HIIT protocol today is the Tabata protocol (named after a Japanese professor Izumi Tabata who published together with other coauthors a 1996 study about the method) and most research is done using it.

Tabata consists of 20 seconds all-out exercise bouts and 10 seconds rest, all repeated 8 times. This results in a 4-minute workout block preceded by 10 minutes of moderate exercise.

The most common form of HIIT consists of several Tabata blocks, usually 4 or 5, although you can successfully use only one 4-minute Tabata block for satisfactory results (this is what the original study did – one 4-minute workout four times a week plus one day of moderate training, all on a stationary bicycle).

The original protocol worked with 10-minute warm up before the 4-minute blocks – that’s is the moderate exercise part of this type of HIIT.

Advantages

HIIT is an incredible fat-cutting tool for those who want to keep their muscle mass. The difference between steady exercise (like 40 minutes on stationary bike or running 5 kilometers) and HIIT is astonishing – while the first will make you look like a marathon-runner, the later gives you the muscular physique of a sprinter. And the best thing about HIIT is that it is real cardio, improving your performance and heart health.

-itimproves resting metabolic rate

-improves maximal oxygen consumption

-lowers insulin resistance

-causes skeletal muscle adaptations that result in enhanced skeletal muscle fat oxidation and improved glucose tolerance

Disadvantages

The main problem with using HIIT is that it can’t be thoughtlessly incorporated in every workout routine. HIIT is a specific way to shred fat and build muscle simultaneously. But while the method cuts fat just as well (if not better) than traditional cardio, it doesn’t build muscle as efficiently as the heavy resistance workout (lifting heavy weights) does.

Almost all scientific studies have shown that HIIT doesn’t cause loss of muscle mass, only fat. Therefore many coaches suggest you can combine your heavy workout with HIIT with no danger of muscle loss.

This is completely wrong. People do not realize that those scientific studies observed athletes doing ONLY HIIT, not a combination of heavy resistance training and HIIT. This is because the researchers are mostly interested in health effects of the workout – they are usually not studying or suggesting new bodybuilding methods.

There are exceptions, of course. For those interested in the topic I suggest my article on concurrent exercise (Combining aerobic and resistance exercise) where you can find references to studies showing that aerobic exercise including HIIT blocks muscle growth if combined with resistance exercise (the classical bodybuilding workout).

Another problem is overtraining. You can’t just add 2 days of HIIT to your 4 days of heavy resistance training unless you have a very special genetic setup. Most mortals will end up with serious CNS over-stimulation and loss of form.

Who can use HIIT and how

If your training aim is moderately muscular body with good improvement in overall form and health, HIIT is the way to go. In other words, most people can achieve an athletic body with this method.

For women who are not into bodybuilding (it means for 95% of all female gym-goers), HIIT is a fast and healthy way to cut fat and achieve good looks.

Ectomorphs (hardgainers)must use this method cautiously, only incorporating small number of Tabata blocks (or other type of HIIT workout) into their training routine, ideally not on resistance-workout days.

On the other hand, endomorphs (people with tendency to be overweight) may benefit from more HIIT incorporated in their weekly routine.

Doing no cardio at all is hardly a good idea for any type of training – even if you don’t need it for your sport (powerlifting is one example) you will improve your heart health and metabolism greatly with some type of aerobic training. And there is hardly a better aerobic training than HIIT.

The golden rules of HIIT

1. Don’t forget that when cutting fat, diet is more important than exercise.
2. Don’t overtrain. Start gradually and always consider the total burden of your weekly training plan.
3. Don’t combine heavy resistance training and HIIT in one day – HIIT will neutralize the muscle gains of resistance training.
4. In bodybuilding and some other sports, you may avoid overtraining by periodizing – switching to HIIT-only workouts during whole or part of your cutting phase.
5. If you try Tabata don’t use static exercises like planks. You can experiment with them but the original protocol is meant to exhaust you during 20 seconds so use, for instance, squat-jumps instead of bodyweight squats etc.

An example of Tabata workout

You can use free weights, own body weight or stationary bike for HIIT. Here is an example:

10 minute stationary bike

Squat-jump with medicine ball

Renegade rows

Dumbbell lunges

Hanging pike

Burpees

Pull-ups

Dragon walk

Clean and jerk

Where possible, the exercises should be done fast, dynamically. Wherever free weights are used caution is necessary but speed is still an important factor.

This is an example of Tabata workout suitable for a strong athlete – possibly bodybuilder. Equipment like dumbbells and barbells is used along with body weight.