“Revolutions are not made by men in spectacles” Oliver Wendell Holmes Sr.
You’ll see the term ARX or ARXFit kicked around here a bit, and listed quite often in my posted workouts. As such, I’ve had quite a few readers ask me to give a more detailed explanation of how this equipment works, and why I like it so much. Machines just don’t figure prominently in my grand fitness scheme, so what’s so special about the ARXFit?
Explanations of how this equipment works is rather a tall order, no doubt. Actually, the intellectual and phisiological basis is not all that tough to explain (as I’ll attempt below). What is tough, however, is relaying just how effective this mode of of exercise is. The fact of the matter is that one session on this equipment with a quick follow-up white board talk could take the place of volumes of writing or blathering. Imagine trying to explain to someone who has never sprinted, just how effective this mode of exercise is. Watching a clip of some one sprinting — or doing battle with ARX equipment — just can’t convey the difficulty or effectiveness of each.
Heh…yeah, so that was back before I found a good flat top barber (they are hard to come by); back, too, when these devices were marketed as CZT (Critical Zone Training) equipment. We think the newer ARX (Adaptive Resistance eXercise) moniker much better conceptualizes this training philosophy. And hey, a nice cameo by Anthony Johnson, of the 21 Convention, is included 🙂
Let me begin this discussion by saying that attempts to more perfectly match the body’s inherent strength curve via various mechanisms/manipulations (again — adaptive resistance) is as old as Milo and the calf. Eugene Sandow devised and sold a home exercise device in the early 1900’s that used rubber tubing as a resistance element. Why rubber tubing? Because it was relatively cheap and, if employed correctly, was actually pretty damn effective. Chains have also been around since the early 1900’s, and were draped over the bar so as to add accommodating resistance to the deadlift and pressing movements. These old-time physical culturalists might not have been able to plot a strength or force-velocity curve (or maybe they could have?), but they did know that these lifts were a hell of a lot more challenging at the bottom of the exercise as opposed to approaching the lockout position. Chains were a pretty crafty answer to this inefficiency. As the bar is elevated (and the body shifts into a more biomechanically advantageous position, (i.e., able to handle additional load) more links of chain come off the floor which increases the load, forcing the lifter the push (or pull) harder to keep the bar moving.
The strength curve graph above, and the following explanation, is an excerpt from this fine NSCA article.
The musculoskeletal system contains three types of strength curves (ascending, descending, and bell-shaped) with different force generating capabilities depending on the changing joint angles and the number of joints involved during the movement. Single-joint movements (e.g., elbow flexion and extension, knee flexion and extension, etc.), generally have bell-shaped strength curves where maximum strength occurs around the mid-phase of the lift. Multi-joint pulling movements (e.g., bent-over rows, pull-ups, etc.) have descending strength curves where maximum strength is produced at the beginning of the movement. Lastly, movements with ascending strength curves include variations of the squat, deadlift, and bench press as maximum strength and force capabilities occur near the top of the lift. Based on the mechanical properties of bands, chains, and the musculoskeletal system, variable resistance modes would be best suited for training ascending strength curve movements.
In the 1970’s elastic bands were promoted and sold as a cheap and viable alternative to the new-kid-on-the-block isokinetic machines that were beginning to gain in popularity. I’d first tinkered with bands and chains in the mid 90s, after devouring everything that Louie Simmons had to say about the subject. And then there was Arthur Jones, and the Nautilus cam. A pretty damn awesome idea, actually — if your limb lengths happened to match the cam specifics; the Nautilus pullover is still one of my all-time favorite machines. And many people don’t realize that one of Jones’ first attempts at revolutionizing exercise equipment was essentially a welded hook to which chains could be hung from a barbell.
But again, all of these innovations were attempts at more perfectly matching the body’s natural strength curve with some manner of accommodating resistance. Louie Simmons took this idea a step further (with bands, at least), attempting to drain more out of the force-velocity relationship of particular movement patterns. And now the hunt was on to find ways to maximize the power output of traditional closed-chain exercises (squat, deadlift, press) as well.
On the power front, it’s fairly safe to say that what limited science there is on the subject agrees with the dictates of ages-old empirical evidence: that it is the intent to move fast over the entire range of motion, and not the actual movement speed that leads to gains in speed strength. This is what training with chains and bands is all about — crafty manipulation of both the strength and the force-velocity curves. Here is a great article from the NSCA if you want to dive into this concept a bit more.
In layman’s terms, chains and bands serve to force the lifter to push as hard as possible throughout a said movement’s entire range of motion, thus creating maximum tension in the target musculature.
According to Zatsiorsky in Science and Practice of Strength Training, 2nd ed. , “[t]he heaviest weight that is lifted through a full range of joint motion cannot be greater than the strength at the weakest point” This obvious truth refers to sticking points and it is based on the fact that strength is joint-angle specific. Strength values will change as joint orientations change, and the weakest orientation is the most limiting one. Therefore, improving the ability to exert force at the weakest joint angle can lead to an improvement in maximal strength performance. Additionally, improving the ability to exert force at every joint angle will have a similar positive effect. When the submaximal effort method (or repetition method) is used, the second phases of lifts are somewhat neglected, and these portions of the ranges of motion don’t receive sufficient training stimulus. If this neglect occurs over a period of several months, muscular strength will not only fail to improve but will begin to drop. In the pursuit of maximum strength, this training outcome, combined with the faulty intermuscular coordination patterns that are created, isn’t favorable.
Now, let’s apply what we now now about effectively matching the strength curve with accommodating resistance to the force-velocity curve. What we want to concentrate on here is effectively and most efficiently targeting the maximal strength area of the force-velocity curve. How best to accomplish that? Barbells and dumbbells can do the job for sure — but, as already discussed, there’s much left on the table. Chains and bands are an awesome step in the right direction, but this method still isn’t perfectly calibrated to each individual’s strength curve; we’re still leaving some efficiency on the table.
So we’ve got two different ideas to think about now: the force velocity curve (power production), and the strength curve. We’ve talked about how chains and bands can be used in an attempt to maximize efficiency of the barbell lifts in these moves, now let’s talk about where the ARXFit equipment maximizes efficiency in these movements.
Remember that the strength curve is the result of force production at various points along the range of motion, and that force production changes because of changes in the joint angle, muscle length, and the involvement of other muscles. The long and the short of it is this: every lifter knows that much more weight can be lifted at the top of a movement than at the beginning. Take the bench press for example; the load used in the exercise is limited by what one can control at the chest (let’s assume no stretch reflex is involved here, for ease of explanation). The upper part of the range of motion, is easier — but the bar is slowing down. Why? Because the arm is only so long, and the bar must return to zero velocity at the arm’s terminus. This means, again, that less force is being applied to the bar at the top of the range of motion. Ugh, more inefficiency. What we need is some device that would perfectly match the strength curve, allowing for maximum force development throughout the entire range of motion, with no need to slow down at the movement’s terminus. This is exactly what the ARXFit accomplishes.
Not only the the ARXFit accomplish this task in the concentric (raising) portion of the lift, but in the eccentric (lowering) portion as well. Eccentric movements have been shown to involve a lower number of muscle fibers than the concentric movement with the same weight. Another way of looking at this is that one is able to handle about 40% more load on the eccentric as compared to the concentric portion of a lift. What if I had a device that allowed for an instantaneous and perfect strength curve match not only concentric, but on the eccentric as well? You guessed it — the ARXFit does it. And now we’re talking some serious efficiency.
Check out the full version if you like, here.
I’ll just drop this anecdotal nugget in and leave it as food for fodder. Since I’ve been associated with Efficient Exercise, and had ready access to the ARXFit equipment, I’ve gained between 7 and 10 pounds of body weight. I wish I’d had a DEXA completed prior to working with this equipment, but I know that I’ve lost a good couple of percent bodyfat in those two years as well. So do the math. My eating habits haven’t changed (i.e., have remained solidly Paleo) in the last 7 years, nor has my workout style and/or frequency. The only things that have changed are that I’m on my feet much more during the day, and I have steady exposure to the ARXFit equipment. In other words, what max effort training I do now is much, much more pinpointed and effective than what I had been able to accomplish via the use of chains and bands.
Make plans to head out to the ATX next spring, where I’ll be demoing the ARXFit equipment and speaking about Efficient Exercise’s HIIRT style of training at the PFX13 symposium. It’ll be one hella good time!
In health, fitness and ancestral wellness –