Rep Cadence and Force: A Personal Anecdote

by Doug McGuff, MD, ©1999

It is my opinion that both practitioners and critics of SuperSlow® have misinterpreted the recommendation of 10 seconds as the ideal repetition cadence. Some SuperSlow instructors are very rigid about the 10 second cadence and berate their clients if the reps are not perfect. Indeed, many SuperSlow enthusiasts have an unrealistic image of Ultimate Exercise (my training facility). They envision muscular clients, in a clinical environment, supervised by a trainer in a white labcoat, who is carefully timing perfect 10/10 repetitions. Let me dispel that myth right away. Whenever I visit other SuperSlow facilities around the country, I am amazed how similar it all seems. It is almost as if we could trade clients, and within a few weeks never notice the difference. Despite my passionate efforts to do things perfectly, we still struggle with motor control issues, we grimace, yell, and frequently go faster than 10 seconds. And you know what?...we haven’t maimed or killed any clients yet.

Many critics of SuperSlow apply the same rigidity to its practitioners when leveling their criticisms. They claim there is nothing magical about a 10 second cadence, implying that Ken Hutchins said there was something magical about it. They claim that you can go significantly faster without undue acceleration and momentum, again implying that the SuperSlow protocol states otherwise. They note that longer stroke movements may require a cadence longer than 10 seconds in order to maintain a similar speed with shorter range movements, again, implying that Mr. Hutchins disputes this. Lastly, many feel that SuperSlow enthusiasts are overly dogmatic about the issue of rep speed. Unfortunately, I believe on this point we are “guilty as charged”, but for two ridiculous reasons. First, we forgot that these accusations are really not part of the SuperSlow protocol. Second (and most importantly), we act as if we are Israelis and Palestinians discussing politics. Seriously, we are talking about weight training, not holy territory.

Having made the above points, I would like both proponents and critics of SuperSlow to go back and read what Ken actually did say on the topic of the ideal speed of motion in Chapter 3 of the Technical manual. Note that he does not canonize 10 seconds, but selects it for convenience. Also, note that he does make the distinction between time and speed.

“Using a meaningful resistance with a typical range of motion; an approximate-6-seconds minimum time per positive excursion (maximum speed) is required to avoid meaningful momentum...At the opposite extreme, a maximum time (minimum speed) for most movements, is in the neighborhood of 15 seconds per positive excursion. At speeds much if any slower, the subject performs jumpy, uneven movements.”

The bolding is added by me to prove my previous points. The ten second cadence was ultimately chosen for convenience and ease of instruction.

“ “10” is a nice round number-easy to work with and remember”
“A ten-second duration is adequately flexible to apply to both short- and long-stroke exercises.”

And regarding the issue of long-stroke exercises.

“In the event, Pullover perhaps, where a 13-second movement seems appropriate, cadence count to 10 in 13 seconds. For the sake of simplicity, don’t impose a 13 cadence count on the novice.”

A little over a year ago, I had an experience which really drove home the above concepts. While racing BMX, my foot came off the pedal while I was going over a large jump. As I landed, I dabbed my foot on the ground, breaking the bone that makes up “ball of your foot”. The fracture was not very serious, and only required me to wear a walking air cast. The fracture occurred on a Friday, and I was scheduled to workout the following Sunday (two days later). Without the air cast to disperse the force over a wide surface area, it was not possible to walk due to pain. Despite the knowledge that I could wait a few weeks before attempting leg press and suffer no real setback, I was stubborn and determined to give it a shot. Initially, I tried to hang my foot over the top of the foot plate while pushing through the heel. Even though the fracture site was not on the foot plate, the traction on the plantar fascia and torque on the metatarsal bone caused severe pain at the fracture site. I then decided to use my standard foot positioning on the foot plate, hoping that it would not cause too much pain.

I set the Med-X leg press up with my next projected weight. I was to use 720 pounds, pinned out at four holes. The seat was positioned so my thighs were perpendicular and my knees were flexed a little more than 90 degrees. I began pushing on the foot plate gradually, and to my surprise, the weight stack began to move...and there was no pain! As I reached the upper turnaround there was a slight twinge and then no pain during the negative. It then occurred to me that I had a very sensitive force detection device in my foot. I thought I would take the opportunity to try different rep cadences and see how fast I could move without crossing the very low force threshold imposed by my broken foot.

I thought I would start with faster cadences. First, I tried the old Nautilus 2 seconds up/4seconds down cadence.....NO WAY! I completed a two second rep and lowered over 4 seconds, but it hurt almost as bad as when I first broke it. I was fearful I might be done for the day. Within a couple of minutes the pain subsided and I decided to press on. Next I tried a 4/4 cadence (recommended by Med-X in their equipment literature). This was much better, but there was still a mild to moderate twinge of pain. Next, I went to a 5 second cadence. To my amazement, a 5 second cadence produced no pain. As I tried slower and slower cadences, the area remained pain free until I tried to go slower than a 15 second cadence. At extremely slow speeds the segmented movement registered quite painfully in my foot. With the aid of my broken foot, I was able to detect a speed/cadence range that produced the most nominal degree of force (at least small enough not to disturb a recently broken bone). Through close observation, Ken Hutchins had defined the range to be between 6 and 15 seconds. Using my broken foot and the Med-X leg press, I found a range of 5-15 seconds. I was amazed to experience for myself how “on the money” Ken really was.

The biggest surprise was not how correct Ken’s estimations were, nor how amazing SuperSlow is in limiting unwanted forces. The biggest revelation for me is that when it comes to limiting force and maximizing muscular loading, I had been paying way too much attention to rep speed and too little attention to the turnarounds. Regardless of the rep cadence being tested, the turnarounds were where the real pain could occur. When I thought about it, this made sense. When you change directions you have to decelerate, stop, and then accelerate again. I found that I could do a 5 second cadence with a perfect turnaround and feel no pain at all. However, a 10 second cadence with a sloppy turnaround would produce a considerable degree of pain. Having had this experience, I have told my instructors to be less concerned with a perfect 10 second cadence (as long as speed is within an acceptable range of 6-15 seconds) and more concerned with enforcing clean smooth turnarounds on compound movements. For an in-depth discussion of proper turnaround technique, instructors my consult Chapter 28 in the SuperSlow Technical Manual.

Lastly, I think SuperSlow instructors need to remember that the technical manual exists to describe how to ideally perform the protocol. It is a bullseye to aim for, even if it is infrequently hit. Almost every great corporation has a detailed policies and procedures manual, but if you look at day to day operations you may see what appear to be infractions and inconsistencies. The CEOs do not concern themselves with this: they know the letter of the law exists so that people can work within the spirit of the law.

Making consistent hole-in-ones would be great, but it is not realistic. But if you consistently make birdie, par, and occasionally eagle...you will win the masters. Finally, we need to be more tolerant of non-protocol experimentation. In upcoming articles I will update the Stasis-vs-Dynamism discussion. We have experimented with some variations which you may find interesting. Though we haven’t been able to reach any conclusions on the burning topics, we have had some interesting insights.