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AssaultRunner Pro Review

The Assault Fitness AssaultRunner Pro is a treadmill for people who hate treadmills. I should know, I hate treadmills and I’ve never been a big fan of running.

However, the AssaultRunner Pro has completely turned me around. I use my AssaultRunner Pro almost daily and although it’s pricey, it’s one of the best home fitness investments I’ve made since buying a barbell and bumper plates.

Note – the Air Runner I previously reviewed has been rebranded as the AssaultRunner Pro, but it’s the same treadmill. I’ve updated the product name throughout this review for clarity.

Should you buy an AssaultRunner Pro?

In case you just want the short answer I’ll say it up front – I love my AssaultRunner Pro

Yes, it’s expensive and takes up a significant chunk of floor space in my home gym. But, I use it almost every day and it definitely has made me a better runner.

It’s more effective than a normal motorized treadmill and the experience is closer to running outside but without having to deal with things like allergies, traffic, and inclement weather.

The AssaultRunner Pro is built like a tank and is one of the few pieces of equipment I’ve tested that I have no major gripes with. The only nitpicky thing I can say about it is that I wish it had options for holding a phone and a bottle of water.

If you can get past the sticker shock and if you have room for it, the Assault Fitness AssaultRunner Pro is definitely worth having in your home gym. Be sure to check the prices on both Amazon and Rogue, I’ve seen sales on both sites at different times.

AssaultRunner Pro

AssaultRunner Pro

What is a curved motorless treadmill?

A curved motorless treadmill like the AssaultRunner Pro has no electric motor to drive the belt. All of the belt movement is driven by the friction of your feet striking the treadmill and pulling the treads toward you.

This is why the running deck is curved – as your foot strikes the tread on the curve, the pulling motion of your foot combines with gravity to ‘pull’ the tread toward and behind you.

The belt is mounted on low friction bearings, so the treads move smoothly as long as you continue providing force through movement.

It’s a very clever design.

Assault AirRunner Review - View of the Bearings

This is where the magic happens

Why buy a motorless treadmill?

I first became interested in motorless treadmills after seeing people rave about them on social media and reading claims that a curved manual treadmill could “make me a better runner”.

I’ve been a lousy runner with a lousy gait all my life and running has never been an enjoyable experience for me.

But I do recognize the amazing benefits that running has to offer, so the thought of a treadmill somehow transforming me into a fleet footed fox was intriguing.

Not intriguing enough for me to buy one without researching them first though, especially since buying an expensive machine flies in the face of my “optimal fitness at minimal cost” ethos.

If I’m going to lay out the cash and sacrifice floor space to own one of these things it has to be worth it.

So I started researching the benefits of a motorless treadmill…

Benefits of a motorless treadmill

There hasn’t been a ton of research done on this topic yet, but I did find a study conducted at the University of South Carolina on the effects of curved motorless treadmills (CMT)* on running mechanics and the results were encouraging. From the study:

The results show that running on a CMT resulted in significant changes in gait characteristics (step length, stride length, imbalance score and stride angle). These findings suggest that running on a CMT can significantly influence running gait.

This was enough to at least get me started looking for a good deal on a CMT, and when a slightly used Assault AirRunner showed up on my local Craigslist I jumped at the chance to buy it.

*The term ‘Curved Manual Treadmill’ is also often used to describe these machines

Assault Fitness Air Runner Review - Installed in the Freedom Corner

Ain’t taking this one, get your own!

1) Improved running form

The main advertised benefit of a curved motorless treadmill is the improving effect on running form, which I touched on above.

I’ll discuss my own experience with how the AssaultRunner Pro influenced my running mechanics later in this article, but the short version is that it has helped me become a better runner and I now run on the AssaultRunner Pro almost every day.

2) Greater speed control

A motorless treadmill like the AssaultRunner Pro offers a more fine tuned control over your speed.

Whereas a motorized treadmill requires you to manually set the belt speed and you as a runner have to adapt to the treadmill, a curved motorless treadmill adapts to you as your pace changes.

Run as fast or as slow as you want without having to push any buttons and the treadmill will speed up or slow down accordingly. It’s not high tech sorcery, just treads moving on low friction bearings. It works very well and makes transitioning between high and low intensity running very easy.

Needless to say, this makes a curved motorless treadmill like the AssaultRunner Pro great for HIIT training.

Assault Fitness AirRunner Review - Treads

Treads rated for 150,000 miles

3) Better running experience

Since a curved motorless treadmill adapts to your speed rather than the other way around, running on the AssaultRunner Pro feels much closer to running outside than running on a motorized treadmill.

You might naturally ask, “Why not just run outside you hoser?”, which is a valid question considering how much a good quality curved manual treadmill can cost.

Unfortunately not all of us live in climates or locations favorable to running outside. I live in Central Texas and the few times of year that aren’t brutally hot and humid are prime allergy season, which sucks for me as an allergy sufferer.

Some folks live in high density urban areas, where traffic and pollution could be problems. Others live in areas where the winters are brutal. I have family in the midwest and none of my relatives are venturing outside in the middle of winter unless they absolutely have to, much less going for a run.

Is the AssaultRunner Pro going to completely replace the experience of running outside? Heck no.

The scenery and the terrain never change when running on an AssaultRunner Pro, so unlike running outside there’s no variation beyond changing your speed.

However, the experience of running on the AssaultRunner Pro is still much more natural than running on a standard motorized treadmill.

4) High calorie burn

Since a curved manual treadmill like the AssaultRunner Pro has no motor, the only power for moving the belt comes from your sustained effort. If you stop moving, so does the belt!

Personally, I can attest to the fact that it does take more effort to run at a set speed on my AssaultRunner Pro than it does to run at the same speed on a motorized treadmill in my office gym.

The experience is very different and I feel like I’ve used much more muscles in my legs after finishing a run on the AssaultRunner Pro versus the treadmill in the office gym.

I’ve also measured my calorie burn while running a mile, and in general I burn around 200 calories when I run a mile at a 5mph pace on the Air Runner as measured using a Polar heart rate monitor.

Assault Air Runner Review - Calories Burned Running One Mile

Running 1 mile at a 5mph pace burned 200 calories

To put that number in perspective, the general rule of thumb is that the average person burns 100 calories per mile while running.

This means I burn double the average amount of calories when running a mile on the AssaultRunner Pro. 

Not bad!

Assault Fitness AirRunner

AssaultRunner Pro Specifications

Here’s everything you need to know about the AssaultRunner Pro:

  • Motor-Free Treadmill / Indoor Running Machine
  • Footprint Dimensions: 69.9″ long x 32.8″ wide x 64″ tall
  • Running surface width: 17.1″
  • Steel Frame & Handrails + Corrosion-resistant Hardware
  • Weight: 280LB / 127KG
  • Treads rated for 150,000 miles of use
  • Built-In Handle and Transport Wheels
  • Digital Console with HIIT and Heart Rate Programs
  • Bluetooth/ANT+ support for Heart Rate Monitors
  • Uses no Electricity – low carbon foot print
  • For All Skill Levels
  • Max user weight: 350lbs
  • 100 low friction bearings

Unboxing and assembly

I bought my Assault AirRunner used off Craigslist, so I can’t directly evaluate the packaging it came in. However, I did have to take it apart in order to get it in my house, so I can confirm it’s pretty easy to assemble.

This promotional video produced by Assault Fitness summarizes the unboxing and assembly steps very well:

As you can see in the video, the treadmill deck comes preassembled. Let me just say, the deck is freakin’ heavy.

Most of the listed 280lb weight of the AssaultRunner Pro comes from the deck alone, so you’ll need two people if you want to bring one of these bad boys inside your house and set it up in a bedroom like I did.

My sweet wife helped me bring it in the house after I took the rails off. We had to tip the treadmill deck up on one end to get it down the hall and through the bedroom door, which was very challenging due to the weight.

She didn’t know what she was getting herself into by helping me, so there was much wailing and gnashing of teeth as we struggled to muscle the AssaultRunner Pro deck into the bedroom without killing ourselves in the process ?

Assault Fitness Air Runner Review - Prominent Branding

Built like a tank and almost as heavy as one

Real world use

So what’s it really like to run on an AssaultRunner Pro?

It’s a very different experience than running on a motorized treadmill. The first time I stepped on the AssaultRunner Pro sort of felt like stepping on a rolling log.

The treadmill belt is very responsive to changes in pace and I kept feeling the treadmill belt speed up underneath me as I walked. It took a bit of practice for me to achieve a smooth consistent pace.

Assault Fitness AirRunner Review - Rolling Log

Test footage of an early AssaultRunner Pro prototype

Using a curved motorless treadmill is an entirely new experience for me so a learning curve is to be expected. The Assault Air Runner is forcing me to be mindful of how I move and it only took me a few minutes to get used to.

Incidentally, I believe this forced mindfulness plays a big part in how a curved manual treadmill can make you a better runner. Allow me to elaborate…

In my experience I’ve found it’s very easy for me to zone out when running on a regular treadmill since the motor is doing the bulk of the work. All I have to do is keep pace with the speed I set.

Even running outside allows me to cheat since I can get away with a half-arsed jog that doesn’t engage much of my leg musculature.

In contrast, the AssaultRunner Pro is enforcing the steady smooth coordination of my brain and limbs by forcing me to be aware of how I’m moving in order to keep a steady pace.

Assault Fitness Air Runner Review - Console View

The AssaultRunner Pro console is easy to read while running

Plus, running on the curved deck is like running on a perpetual slight incline, which forces me to keep a more upright posture and engages more of my leg muscles.

As a result of these changes, I’ve learned to appreciate running and I regularly run 5-7 miles every week on the AssaultRunner Pro. I’ve actually ran more miles on the AssaultRunner Pro in the few months I’ve owned it than I have in the last ten years combined.

AssaultRunner Pro and barefoot running

Much ink has been spilled (and probably some blood) on the debate over heel strike vs forefoot strike running styles.

For what it’s worth I fall in with the forefoot striking camp and I prefer a minimalist shoe (or bare feet) when running.

I’m happy to say the AssaultRunner Pro is very friendly to minimalist footwear and barefoot runners. When I run on the AirRunner I’m either wearing Nike Flyknit shoes (which barely qualify as minimalist, don’t roast me), or a pair of thin athletic socks.

I also run barefoot, although I usually wear socks to keep my AssaultRunner Pro treads clean. The first time I ran barefoot on the AssaultRunner Pro I was concerned the treads would pinch the soles of my feet, but it’s never been a problem.

If you happen to be considering a transition to minimalist or barefoot running, the AssaultRunner Pro is a good way to make that transition. The AssaultRunner Pro treadmill deck has a small amount of give that makes it more forgiving on your feet than hard ground.

Just take it slow and ease into it, your feet will need time to adjust!

AssaultRunner Pro console

The AssaultRunner Pro console has a well designed intuitive interface. The display provides time, distance in miles or kilometers, speed, watts and pace

All this information is clearly shown and easy to see at a glance.

Assault Fitness Air Runner Review - Console Features

By the way, the “integrated phone/tablet shelf” is pretty much useless.

If you put your phone on the “shelf” it blocks the view of the entire console ?

Assault Fitness Air Runner Review - Phone Blocking the Console

Who needs a console when you’ve got sweet tunes? ¯\_(ツ)_/¯ 

In fact the lack of any kind of storage for a phone or water bottle is my biggest gripe with the AssaultRunner Pro.

It’s a petty thing but it sure would be nice to have.

AssaultRunner Pro vs TrueForm vs Woodway vs Xebex etc

The AssaultRunner Pro is just one of several different brands of curved manual treadmills available on the market. The basic principle in all of them is the same, but there are differences in the user experience with each one.

I’ll briefly summarize the differences between the AssaultRunner Pro and other curved motorless treadmills I gleaned from various reviews of the other machines while researching motorless treadmills.

Trueform Runner

The Trueform Runner is held up as the gold standard for curved manual treadmills.  According to some reviews a shorter running deck and higher belt resistance make it “harder” to run on than the AssaultRunner Pro, especially at low speeds.

The Trueform Runner display console is also not as sophisticated as the one on the AssaultRunner Pro.

On the plus side, the Trueform has several options for customization such as simulated turf and custom color options.

Woodway Curve

The Woodway Curve has a very steep curve angle and some people say they feel unstable at high speeds.

I got the impression from reading reviews that the belt moves very quickly, and there’s some debate as to whether or not the Curve uses a flywheel to maintain a constant speed.

The most recent versions of the Curve look like they use a sophisticated touch screen monitor, but I’m not sure if this is a standard feature or an extra add on.

Xebex Runner

The Xebex Runner is very similar to the AssaultRunner Pro and the user experience is similar as well. I know this because due to a recent move I now own a Xebex AirPlus Runner.

The Xebex Airplus Runner has the advantage of doubling as a weight sled, so it’s definitely worth checking out.

Be sure to check out my full review of the Xebex AirPlus Runner.

Bottom line

So there you have it. I love my AssaultRunner Pro. I used it almost every day and I was sorry to see it go.

The AssaultRunner Pro is built like a tank and is one of the few pieces of equipment I’ve tested that I have no major gripes with. The only nitpicky thing I can say about it is that I wish it had options for holding a phone and a bottle of water.

If you can afford it and if you have room for it, the AssaultRunner Pro is definitely worth having in your home gym.

Feel free to ask any questions in the comments if there’s something you’d like to know that I didn’t cover!

AssaultRunner Pro

Assault Air Runner

About the Author Mario

I'm a software product manager with a full-time job, family, and a desire to stay strong, mobile, and fit. I separate fact from fiction to find the most effective and affordable options for home fitness. If you'd like to build your own home gym, start here.

  • Keith says:

    Thanks for the review. How is it for walking on as my wife is more of a walker than runner?

    • Mario says:

      It’s great for walking as well as running. My wife uses it to walk and loves it. However, since it isn’t motorized walking (and running) on it does take a little getting used to. Walking on it for the first time can feel like the treadmill is speeding up under you until you get the hang of it. But once you do it becomes second nature.

  • Charles Cesare says:

    Just got my air runner, tread movement resistance seems too free and not able to slow speed. I get a feeling it is running away with me. Any suggestions?

    • Mario says:

      Congrats on your new toy! It’s going to take a little getting used to a motor-less treadmill if you’ve never used one before, try walking on it for a while till you get the hang of it, then move up to slow jogging, then running.

  • Gustafson Bruce says:

    With the Assault Pro and the bluetooth connection, you can connect to apps such as Zwift which is free for running and makes the longer runs on the trainer more interesting – and keeps track of your runs and easier to see you numbers (ie. pace, time, speed, etc) while working out if you are using the Zwift app on a large screen through AppleTv.

  • Jordie Skinner says:

    Great review! Wondering how it is for endurance training? How would it handle for a 8km to 15km run?

    • Mario says:

      Yes, it’ll work just fine for long runs, your biggest concern will be fighting off boredom from the lack of scenery change lol.

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