FIIT Boss Level is the world’s hardest home workout. I tried it, so you don’t have to

It burns over 1,000 calories in 90 minutes, and the ‘rest’ portion is actually a 5-minute plank

I tried Fiit Boss Level
(Image credit: Fiit)

There’s home workouts… And then there’s FIIT Boss Level. If you’re looking for a true exercise challenge, this fat-incinerating, sweat-drenched torture session is hard to beat, in every sense. 

I like a good workout challenge as much as the next social media influencer. It’s been a while since I did the 10,000 swings kettlebell challenge, so when I heard about FIIT Boss Level, “the world’s toughest home workout” I felt compelled to try it. It promised a “gruelling 90-minute workout” that’s been “specifically designed to challenge even the fittest members” of the Fiit family. And after completing the workout, I can certainly confirm that Boss Level is indeed a challenging workout.

Boss Level, the latest HIIT workout in Fiit’s ever expanding library, launched on 7 June 2021 and has been tried by over 6,000 hardy souls, of whom a mere 450 completed it. I can now see why.

You see, Boss Level is not a traditional HIIT workout when your heart rate goes up and down periodically. No, here, your heart rate goes up in the first five minutes and stays there for the duration of the workout. Which is 90 minutes. I was a bit confused at first because I was expecting a HIIT-like structure but around 35 minutes in, my heart rate being through the roof and profusely sweating, I remembered the description never mentioned it being a HIIT workout. Uh oh, I thought. This is going to hurt.

I tried Fiit Boss Level

(Image credit: Fiit)

Fiit Boss Level workout – Part 1: your workout is my warmup

But before I realised how F-up I was, things were going swimmingly. Although it was a bit suspicious how hard the instructor went during the warmup, considering they’d need to keep the pace up for another 90 minutes, I thought surely, things will even out and we’ll be given a little break before we start the ‘actual’ workout.

I was wrong.

Each part of Boss Level is done by a different instructor who goes as hard as they can while you’re just trying to survive on the other side of the screen. After a whole 40 seconds of rest, we jumped right into the first workout section, ‘Non Stop’. ‘Non Stop’ only lasted for 9 minutes but as the name suggests, it consisted of non-stop bodyweight plyo moves and took my heart rate to a whole new level.

After a minute break, we went on to do the ‘Devil’s workout’, 3-minute blocks of AMRAP workouts with weights and honestly, my body was starting to give in already. It didn't help that I haven’t got a light enough dumbbell that can be used for such workouts so I was struggling to keep the pace.

I tried Fiit Boss Level

(Image credit: Fiit)

Fiit Boss Level workout – Part 2: ‘active recovery’ my a**

I started to lose focus around the ‘Buy in/Buy out’ section. These were sequenced moves and since my brain was already foggy, all I did was stare at the screen, trying to replicate the instructor’s moves, unsuccessfully. Worse still, each cluster was followed by an extra move which I never anticipated in time, adding to my confusion of what I was supposed to be doing.

And then came the ‘active recovery’ part which was – and I’m not joking – a 5-minute long unbroken plank. And we aren’t talking about holding a standard low plank for that long, no, but different versions, like X-reach plank and starfish plank, changing positions every 30-45 seconds. Even the instructor was sweating and they didn’t even do the half an hour workout beforehand.

Needless to say, my 5-minute plank was far from being unbroken but truth to be told, my heart rate went down a bit so that was good. The ‘relief’ only lasted for a minute as we went right into ‘Explode & Reload’ and we busted out those dumbbells yet again. My body was aching from head to toe but mainly my glutes, hamstrings and shoulders. As a matter of fact, when I’m writing this now, my glutes are experiencing a healthy dose of DOMS, two days after the workout. I was ready to be done with the workout.

I tried Fiit Boss Level

(Image credit: Fiit)

Fiit Boss Level workout – Part 3: the end is barely in sight

But the workout wasn’t done with me. After the gruelling ‘Explode & Reload’ section, where even the instructor was out of breath, let alone me, we went into ‘Intervals’ with even more dumbbell and plyo moves. I was seriously slowing down but even so, my heart rate was high and my calorie counter in the top right corner was going faster than an altitude meter of a plane going into nosedive.

After this, there was a slight theatrical pause which would make more sense if I couldn’t see the times in the bottom right corner of the screen, knowing full well the workout couldn’t end just yet, so I wasn't surprised when I was told by the instructor that there is still another block to go. In the ‘EMOM AMRAP’ section, the instructor went hard and I tried not to collapse from exhaustion. There was a lot of shouting and ‘we are all crazy here!’ comments but honestly, I was just trying not to stop working out.

After this 10-minute dumbbell orgy, the 15-minute stretching session also showed me just how stiff I am but at least it was over: the workout lasted for 1 hour 34 minutes 7 seconds and I burned just shy of 1.200 calories (1,195 to be precise). My average heart rate was 144 bpm and I collected 3,325 Fiit points, hurray!

Fiit Boss Level workout: rinse, repeat?

I generally don’t participate in group classes, nor do I care much about instructors trying to encourage me to workout harder. The Boss Level was all that, but exaggerated: more shouting, more jumping and more sweating. During the workout, I often felt cheated when a new instructor jumped in and asked me to work harder. You just got here; I’ve been doing this for an hour! 

All that said, I really enjoyed the challenge Boss Level provided and although I wouldn’t want to do it too often, if you’re planning on improving your fitness level, doing the Boss Level can be a good benchmark to see how much your fitness level improved over time. Or declined.

Boss Level is one of the 700+ on-demand beginner, intermediate and advanced classes on Fiit, housed across its three studios: Cardio, Strength and Rebalance. Start a free Fiit trial today

Fiit Boss Level workout: try these too

We have loads of amazing workouts here on T3, including a 20-minute kickboxer strength and flexibility workout, a 10-minute medicine ball workout, a quick jump rope workout and 12-minute boxing workout, all with follow along videos included in the article. If you have a kettlebell at hand, this is the best kettlebell workout you should try. For those with access to a barbell and weight plates, we recommend the ultimate full body workout or what we think is the best push-pull-leg workout.

Matt Kollat
Section Editor | Active

Matt Kollat is a journalist and content creator who works for and its magazine counterpart as an Active Editor. His areas of expertise include wearables, drones, fitness equipment, nutrition and outdoor gear. He joined T3 in 2019. His byline appears in several publications, including Techradar and Fit&Well, and more. Matt also collaborated with other content creators (e.g. Garage Gym Reviews) and judged many awards, such as the European Specialist Sports Nutrition Alliance's ESSNawards. When he isn't working out, running or cycling, you'll find him roaming the countryside and trying out new podcasting and content creation equipment.