High Intensity Interval Training (HIIT): Why It Works

When it comes to the gym, I love weight lifting but I hate cardio. If you’re an avid reader of my blog, you’ll already know how much I like to gush about powerlifting.

But when it comes to cardio, it’s a different story. It takes a lot of time and when you’re in the gym, your schedule can be tight. I used to find myself organizing gym days that were dedicated to just sitting on the exercise bike and chewing through and hour or two of cardio.

I’m pleased to say I don’t do that anymore. The only type of exercise I do on bikes now is HIIT, also known as High Intensity Interval Training.

What is High Intensity Interval Training?

HIIT is a much shorter, but a lot more intensive version of cardio. You can do it using any of the traditional forms of cardiovascular exercises like running, biking, skipping… however you up your stamina.

The main difference is that it takes a fraction of the time. In its most basic form HIIT works by doing low intensity cardio for a short amount of time, let’s say 1 minute, followed by grueling high intensity cardio, or sprinting for another minute. You swap backwards and forwards between both intensities and it really puts your body through its paces.

The exercise bike in my gym has 25 levels. Level 1 is the lowest intensity, and it gets more difficult from there.

Here’s an example of what I do, usually at the end of a weights session that doesn’t involve legs:

  1. I start on Level 5 and I push for a minute.
  2. After that minute I up it to Level 20 and I just hammer it for a full 30 seconds.
  3. Then I go back to Level 5 for another minute.
  4. I rinse and repeat this method until I’ve done 10 sets of that 30 seconds of death.

That’s it in a nutshell. Sometimes I’ll try going for a full minute on Level 20, but I can never make it the full 10 sets. I keep trying though.

It’s hell but it definitely works for ripping the fat off.

Why does HIIT work so well?

HIIT is the most brutal form of exercise I do. But I keep doing it, because the health benefits are great.

Here’s a short list of the some of the reasons I hang in there twice a week and why I will continue to do so:

You Keep Burning Calories Post-Workout

This is one of the major benefits, especially if you’re trying to cut fat – you’ll keep burning fat long after the session is done.

So, why does this happen? Because of the intensity of the workout, your body has to do a lot of work to repair itself. Especially as you keep lulling it into a false sense of security by switching between light and heavy intensity.

Your body can spend up to 24 hours recovering itself after a good HIIT workout. In doing so it uses more energy to keep this up. The results is that you burn more fat and calories throughout the day to keep you going.

Great for Endurance

One of the other great benefits of HIIT is that it gives your body a serious boost when it comes to stamina and endurance.

You’re essentially making yourself sprint on and off for a long period of time. One study showed that participants engaging in HIIT over an 8 week period saw 100% increase in the amount of time that they could hold a sprinting pace for on a bike (study).

It’s great for both cutting fat and getting fitter.

Burns the same as boring cardio – but faster!

Another perk of HIIT is that it can burn the same amount (or more) calories than normal steady-state cardio but in a much shorter period of time.

Because you’re sprinting at a very high intensity during a HIIT session, you’re going to be burning a lot of calories. Studies show that pounding away at a 15 minute HIIT session is just as effective as an hour of jogging on a treadmill for an hour.

You Can Do It Anywhere

One of the great benefits of HIIT is that you don’t need any equipment do it, or a gym membership. Although I use a bike to do my HIIT, it’s not compulsory.

You can do any form of cardio for HIIT. A good example of what would work if you are tight on cash or equipment would be sprinting. Running between lampposts would be a good idea. You could sprint past 3 lampposts, and then jog past another 3 when you’re running out in the street.

Summary – HIIT

In summary, HIIT is a simple yet challenging form of cardio which can help you burn a lot of calories while also boosting your overall stamina and endurance.

Do I recommend it because it’s fun? No, I recommend it because it’s hard and effective. If you’re not prepared for pain, this isn’t the type of exercise for you. However, if you’re hungry for results and willing to do whatever it takes – you should give this exercise a try.

If you need help getting starting, here’s a great beginners workout for HIIT from the Body Coach.

Happy Training!

– JD