The Ten Requirements for Full Range Exercise Explained

Arthur Jones was an exercise pioneer who created Nautilus and MedX strength training equipment. These machines were, and still are, light years ahead of what preceded them and what has come along since (the lone exception being Super Slow Systems equipment). Ken Hutchins, who created the Total Results exercise protocol, has said that exercise as we know it would not have been possible without Jones's initial concepts on machine design and exercise philosophy, and every person who pursues meaningful exercise owes Jones a debt of gratitude. Jones was an interesting character who unfortunately passed away in 2007. He was a self-educated man born in Arkansas and grew up in a family of physicians in Oklahoma, and outside of exercise he worked as a writer, producer, and television director, and also owned and operated a zoo in Louisiana after World War II. I am not certain of the date that Jones developed the Ten Requirements for Full Range Exercise, but I believe it was not long after the first Nautilus machines hit the market in 1970.

These are the Ten Requirements for Full Range Exercise:

1. Rotary resistance. This means that the involved joint of the body in a given exercise must have resistance rotating on a common axis.

2. Direct resistance. Resistance must be directly encountered by the involved body part.

3. Variable resistance. Your muscles are stronger in some positions and weaker in others, so the resistance must be varied in order to target the muscles properly.

4. Balanced resistance. This goes along with the third requirement.

5. Positive work. There must be resistance applied to the musculature during the concentric (muscle fibers shorten) phase of the movement.

6. Negative work. Resistance must also be applied during the eccentric (muscle fibers lengthen) portion of the exercise.

7. Stretching. Resistance should be provided in a range of motion that exceeds the limits of the user.

8. Pre-stretching. This involves a slightly greater range of motion just prior to the start of the positive phase of the movement. More on this later.

9. Resistance in a position of full muscular contraction. There must be resistance in the finishing portion of the movement, so that the musculature is not unloaded at any time.

10. Unrestricted speed of movement. The mechanics of the machine should not limit how fast or slow you move.

It must be understood that Arthur Jones created Nautilus machines back in the late 1960s because he recognized the inherent limitations in free weights and Universal machines, which were the only strength training equipment available at the time. Nautilus machines were an intellectual and mechanical quantum leap forward, and while they were revolutionary, Jones's equipment had some design flaws in the form of friction, backward cams (the mechanism that varies the resistance through the range of motion), and independent movement arms on a few machines. Some of these flaws he worked to improve, while others he steadfastly refused to change. Nautilus protocol involved a two second positive phase and a four second negative phase, so some of the meaningful effects of the cam were obviated by a faster than acceptable movement speed. The Ten Requirements for Full Range Exercise should be taken into context with what was known more than fifty years ago. We have learned much since then.

Which of the requirements have been invalidated? The first is rotary resistance; in reality, Jones uses an incorrect term here. As Ken Hutchins points out, "Technically, there is no such thing as a rotary resistance. Resistance is force. And force always exists in a straight line. What we are really talking about is torque. Torque is often imagined as a twisting force, but actually it is merely a product of straight-line force and lever length" (his emphasis). Pre-stretching is very dangerous and is thus invalidated. Pre-stretching involves a sudden and violent jerk at the end of the negative just prior to the next positive repetition. This can only be accomplished with a machine setting that exceeds a safe and pain-free range of motion. This concept came into being as a result of a misguided emphasis on flexibility, but is far more likely to result in injury than it is to bring about benefit. It is incumbent upon the exercise instructor to determine proper machine settings for each client. Finally, an unrestricted speed of movement is also likely invalidated, because it implies that one should be able to move faster during exercise rather than slower. An exercise subject should always move more slowly during strength training rather than faster, and as I mentioned above Jones advocated a much faster speed of movement than I would consider safe. I should also point out that since Nautilus machines often had high amounts of friction in the weight stacks, it was very difficult to move at an appropriately slow speed without the movement arm getting hung up during the negative excursion.

The rest of the requirements remain valid, although further clarification is needed for a few of them. A properly designed exercise machine must provide direct, variable, and balanced resistance. The need for variable resistance was mentioned above, and is a primary reason why Jones designed the Nautilus cam in the first place. Barbells and dumbbells do not allow for variable resistance, and a 50 pound barbell will have the same resistance no matter what position of the range of motion you are in. This is a limiting factor, because the resistance can be too heavy in some portions of the range of motion and too light in others. Only a machine with a cam can appropriately match strength with resistance based on leverage factors. At Total Results we do use a barbell to perform the bicep curl exercise, but that's only because we do not have a machine (or the space it would require) to address that exercise. Positive and negative work remain valid, as both the concentric and eccentric phases of the movement are equally important for achieving an exercise stimulus. Stretching remains valid, but far too much emphasis has been placed on flexibility, in my opinion. We make sure each client is able to utilize a safe, but pain-free range of motion on every exercise, and that will enable them to maintain and improve functionality. Lastly, resistance in the position of full muscular contraction, at least in theory, remains valid, but it's more correct to use the term "most contracted position" instead. To say that a muscle is fully contracted in any position is misleading.

Many of the Ten Requirements of Full Range Exercise are the foundation for equipment design. Ken Hutchins was able to take these requirements to another level when he designed Super Slow Systems equipment, as these are a quantum leap beyond the initial designs for both Nautilus and MedX machines. All of the machines at Total Results meet the requirements put forth. This is just one way that we separate ourselves from our competition, as most other commercially-available equipment is poorly engineered. The fact that a few of the requirements have been invalidated over the years should not in any way diminish Jones's accomplishments or ideas. Many scientific discoveries throughout history can seem less significant as more knowledge has been gained and time has passed. An understanding of the Ten Requirements for Full Range Exercise gives us a greater appreciation for the Total Results philosophy, and we would not be where we are today without the contributions of Arthur Jones.