Is Insanity better than HIIT for fat loss? This article compares both training styles and crowns a champion.

Insanity vs HIIT: Which Is Better For Fat Loss?

Written by Russ Howe PTI, and most recently updated 1 day ago.

8 min read

High intensity interval training (HIIT for short) is widely regarded as the best type of cardio for fat loss, but now there’s a new challenger to the throne.

Yep, it’s Insanity.

Promising shorter workouts and better results, the boffins at BeachBody believe they can turn you into “a 24/7 fat burning machine” with a new-fangled technique called MAX interval training, and they’re confident it blows all other forms of training (including HIIT) out of the water.

I’ll be comparing Insanity vs HIIT in this article to see whether they’re speaking facts, or talking shit.

The Commercial To End All Commercials

insanity vs hiit

Before we do any head-to-head comparisons of Insanity and HIIT, I’d like to give huge props to whomever designed those late night informercials.

They really excellent!

Trust me, if you’re sat in your underwear at 3 A.M. holding a scrumpled up cake box and feeling an overwhelming cloud of guilt (I speak from experience!), you’re primed and ready for these guys to explode onto your TV screen and tell you they can make it all go away for three easy payments of $99.99. Even the toughest of skeptics would be convinced by the end of this 30-minute-sell-a-thon, such is the elite level of marketing on display.

Unfortunately for BeachBody I’m not a skeptic, I’m a fitness professional. That means they need to delete the hype and bring the science if they want to convince me they’ve discovered the holy grail of fat loss.

(But it’s a great advert nonetheless!)

So let’s start by addressing the subtle differences between high intensity interval training and Insanity:

interval training vs max interval training

Is Insanity Better Than HIIT For Fat Loss?

insanity workout review
Action movie star Adam Baroni stops by for an outdoor sprint session based on the principles you see above.

Both training styles are very effective for fat loss and improving your fitness levels, but if I am forced to pick a winner then HIIT comes out on top.

Don’t get me wrong; Insanity definitely has its merits (even if the whole thing is just a glossy sideshow so BeachBody can push their over-priced supplements at you in the commercial breaks), and if you run the program from start-to-finish you can achieve a very good transformation.

I know this from first-hand experience, because I used it as my sole training program for two years back in 2015-16.

However, there are big reasons why HIIT remains the undisputed champion of fat loss.

1. HIIT Offers Greater Progression.

It was Rita Mae Brown who said:

The human body is amazing at adapting to its workload over time, and that’s especially true in the gym.

That’s why we must find ways to make our training more challenging as we become fitter, stronger, and more able to handle the stress of our current program. This is called the progressive overload principle, and it’s one of the key drivers of building muscle and gaining strength.

So the problem with Insanity (or any other home workout plan of the same ilk) is that when you complete it you don’t really have anywhere else to go, except returning back to the start and re-running it, promising to “go even harder” (more on this in a moment).

Meanwhile, HIIT is absolutely perfect for this because it’s based upon the same concept as weight training, so just as you’d increase the weight you’d lift on a set in the gym, you’d increase the difficulty of your HIIT workout by shortening the length of your recovery phases between each HIIT burst. This enables to you create a more challenging workout, now for a fitter pair of lungs, and see continued results.

(The reason you’d shorten your recovery phse and NOT lengthen your HIIT burst is because HIIT is designed to have you attacking each burst at a high intensity, and most people can only hold that for 30 seconds or so.)

2. You Will Suffer Fewer Injuries.

Most notably the ACL.

ACL issues are typically caused by twisting awkwardly while trying to land a rep at high speed, and Insanity just so happens to feature an absolute fuck-tonne of exercises which make this inevitable (burpees, power squats, jumping lunges, etc).

Considering that the late night infomercials are aimed at beginners, most of these injuries generally occur due to poor technique, but sometimes even experienced trainees wind up on the shelf. As mentioned in the previous section, I believe this is because they have re-started the program and are attempting to “outwork” their previous self (i.e. doing more power squats in 30 seconds, push higher on jump lunges, etc) in order to see continued results, which creates a situation where even advanced trainees can fall victim to an awkward twist, or a bad landing.

insanity vs hiit

3. HIIT Gives You More Variety.

It looks like there’s a lot of exercises in Insanity, but it doesn’t take long before you start getting bored.

Fuck me, if I have to do one ore burpee I’m gonna snap the neck of the next motherfucker who walks by (which is not great when you’re training at home)!

HIIT is un-fucking-beatable on this front, because the whole principle revolves around TIME and not EXERCISES. That means you can apply it to anything – as long as you are working flat out for 30 seconds and recovering for 1-2 minutes, you are doing HIIT. So one week you could be slamming a medicine ball, the following week you could be pounding the treadmill, then you could go for a swim, etc. It’s all HIIT.

is insanity hiit
Team GB Olympic athlete Amanda Lightfoot slams a 40kg bag during a HIIT session at the gym.

4. HIIT Activates More Type 2b Muscle Fibers

The subtle differences in the way HIIT and HISS (or MAX Interval Training) are stuctured mean they trigger slightly different responses from the body in terms of muscle fiber development.

This can have a huge impact on the type of body you build.

You see, your muscles consist of three types of muscle fibers. Type 1 fibers are mainly used for endurance-based activities, and type 2b fibers are mainly used for strength-based activities, meanwhile type 2a fibers have the capacity to transform into either additional type 1 or additional type 2b muscle fibers, depending on what kind of stress the body is being subjected to.

And here’s the thing:

Any form of prolonged steady state cardio (even when performed as ferociously as Insanity) will trigger those type 2a fibers to become additional type 1 muscle fibers to help the body adapt to all of the endurance training it is being tasked with. Both HIIT and weight training go in the opposite direction, triggering those type 2a fibers to become additional type 2b muscle fibers instead. This is important to know, because lots of gymgoers want to become chiselled, stronger physique, therefore it makes sense to structure your training in a way which prioritizes creating more of those crucial type 2b muscle fibers. (4)


  1. Trembalay, A., et al. Impact Of Exercise Intensity On Body Fatness And Skeletal Muscle Metabolism. Metabolism (1994).
  2. Knab, A. M., et al. A 45 Minute Vigorous Exercise Bout Increases Metabolic Rate For 14 Hours. Med Sci Sports Exerc (2011).
  3. Mangine, G. T., et al. The effect of training volume and intensity on improvements in muscular strength and size in resistance-trained men. Physiol Rep (2015).
  4. Wilson, J. M., et al. Concurrent Training: A Meta Analysis Examining Interference Of Aerobic And Resistance Exercise. J Str Cond Res (2011).

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I’m Russ. I’ve been a personal trainer since 2002, and I own

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