Weighing in on ARX
by Dr. Douglas Graham
Published: Thu, 11 Apr 2019
I was recently asked about ARX, the latest in what has been a long line of "revolutionary" fitness machines. My reply follows.
ARX, short for adaptive resistance exercise, will work to some degree, if you work it, boring though it may be. BUT, and I'm not referring to the big butt you'll get if you do ALL your exercise sitting down on an ARX machine, the problems with such exercises are many-fold, and are only compounded by the fact that you're sitting. Listed are just some of the most profound issues.
The machine offers a wide variety of isolated "simple" movements, simple meaning that the work is performed by only one joint. As such, little to no core strength or stability is required, hence none is developed. This means you must do many different exercises in order to achieve the simple goal of gaining full body strength.
But the body is designed for complex movements that cross several joints at once, strengthening the core while using it for stability.
Exercises are performed horizontally rather than vertically. Maximum bone density development occurs when bones are aligned in opposition to gravity. In life, our bones need strength when challenged by loads that mount vertically.
I ask you to watch it at least three times, but only a few seconds of the clip. First watch at normal speed. You only need to watch from 2:55-3:08, which is the section clipped here. Then watch it in slow motion, at 1/4 speed. Pay attention to the top of Stefi's right thigh, where it meets the hip. Or just watch the back-most part of her right butt cheek. You will see that rather than moving straight up, as you'd expect it to if she was in perfect position, (and as it would if she wasn't lifting a maximal load, even if she wasn't positioned perfectly, so she could overcome the positional error with brute strength) her midsection is moving all over the place as she tries to find balance combined with the sweet spot for optimal mechanical advantage. She shows dozens of tiny weight shifts from 3:00-3:03. She goes forward, backward, left, right, diagonal, twists, and even corkscrews a bit; she's looking everywhere for the perfect spot where she will get maximum mechanical advantage. That's proprioception, and it develops the same way as does all fitness, through overload and recovery. You get NONE of that sitting on an ARX doing leg press...let alone the core and trapezoidal development she gains by deadlifting a heavy load.
ARX, short for adaptive resistance exercise, will work to some degree, if you work it, boring though it may be. BUT, and I'm not referring to the big butt you'll get if you do ALL your exercise sitting down on an ARX machine, the problems with such exercises are many-fold, and are only compounded by the fact that you're sitting. Listed are just some of the most profound issues.
1. Isolated Simple Movements
The machine offers a wide variety of isolated "simple" movements, simple meaning that the work is performed by only one joint. As such, little to no core strength or stability is required, hence none is developed. This means you must do many different exercises in order to achieve the simple goal of gaining full body strength.
But the body is designed for complex movements that cross several joints at once, strengthening the core while using it for stability.
2. Horizontal
Exercises are performed horizontally rather than vertically. Maximum bone density development occurs when bones are aligned in opposition to gravity. In life, our bones need strength when challenged by loads that mount vertically.
3. Pushing
Pushing a leg press machine is not the same movement as performing a weighted squat, as it does not require the same movement mechanics, thus it will not give you the same package of benefits to transfer to running.4. Twelve Minutes
Red flags should go up when the (misleading) ARX advert tells you that you can fulfill all your exercise/fitness requirements in "12 minutes, 2-3 times per week." No fitness program can do that. Heck, no one can even warm up for exercise that quickly.5. Combo
Does the ARX offer value when used in addition to a full and well-rounded fitness program? Sure.6. Proprioception
We must continually develop our neurological abilities (proprioception, kinesthetic awareness, balance, etc) or they quickly fade. No machine can give the proprioceptive feedback and development that free weights provide. ARX says gyms haven't changed and are thus old fashioned and out of date. Gyms haven't changed BECAUSE free weights work best. Watch this clip in full screen, on your computer rather than a telephone, if possible.I ask you to watch it at least three times, but only a few seconds of the clip. First watch at normal speed. You only need to watch from 2:55-3:08, which is the section clipped here. Then watch it in slow motion, at 1/4 speed. Pay attention to the top of Stefi's right thigh, where it meets the hip. Or just watch the back-most part of her right butt cheek. You will see that rather than moving straight up, as you'd expect it to if she was in perfect position, (and as it would if she wasn't lifting a maximal load, even if she wasn't positioned perfectly, so she could overcome the positional error with brute strength) her midsection is moving all over the place as she tries to find balance combined with the sweet spot for optimal mechanical advantage. She shows dozens of tiny weight shifts from 3:00-3:03. She goes forward, backward, left, right, diagonal, twists, and even corkscrews a bit; she's looking everywhere for the perfect spot where she will get maximum mechanical advantage. That's proprioception, and it develops the same way as does all fitness, through overload and recovery. You get NONE of that sitting on an ARX doing leg press...let alone the core and trapezoidal development she gains by deadlifting a heavy load.