The Ten Requirements of Full-Range Exercise

by Ken Hutchins

The Ten Requirements of Full-Range Exercise are the original work of Arthur Jones. They constitute a logical framework of exercise and equipment analysis that developed and evolved as Arthur derived the Nautilus® Principles of Exercise. Here, I present them as they were originally intended by Arthur -- that is, once he finally settled on its exact makeup after several years of intellectual development. First, I list them in the sequence often used for quick recall, logical presentation, and associated grouping. Then I explain each, one at a time.

Rotary Resistance Since joints -- particularly appendicular joints, those most associated with our ability to move in our environment -- function to rotate; exercise equipment must so conform. Many conventional exercise tools operate linearly in an attempt to provide resistance to a limb that rotates about a joint. One cannot travel linearly while forced to move in an arc -- at least not as viewed from a perspective perpendicular to the plane of rotation.

Note that as you view rotation of a joint and limb in their plane of rotation, rotation merely proscribes a straight line, misleading your perception to interpret that no rotation occurred when, indeed, it did occur.

Direct Resistance In many conventional exercises, the targeted musculature is poorly loaded and inroaded because the resistance is filtered through weaker structures between the targeted musculature and the resistance source (equipment).

For example, although you might perform a chin-up to target the arm muscles, more likely you perform this exercise to target the larger, stronger torso structures: latissimus, pectoralis, abdominals. These larger structures are poorly addressed because the smaller structures of the arms and the yet-more limited gripping muscles of the hands and forearms fail long before the torso targets. This problem is termed indirect resistance. This problem is solved by placing the resistance directly against the body part directly and immediately moved by the target musculature. By placing the resistance against the upper arms -- as provided in the Nautilus Pullover machine -- the problem of indirect resistance for the latissimus and pectoralis encountered while performing chin-ups is solved.

Variable Resistance The strength of a muscle -- as noted by force outputted to the appendage it directly moves -- changes per position. In other words, a muscle-joint-limb structure is stronger in some joint positions and weaker in others. Therefore, a proper exercise machine must also vary the resistance to permit complete range of motion.

Balanced Resistance It is not enough to say that variable resistance is required in an exercise. Most, if not all, exercises do vary but they vary inappropriately to the needs of the muscle-joint-limb structure or to the needs of efficient inroad.

Positive Work Most exercise will naturally incorporate the potential for positive work, also known as resistance during the concentric (shortening) phase of muscular contraction.

Negative Work Some exercise equipment is designed devoid of negative work potential. This results in an undesirable respite of muscular loading, and thus poorly efficient inroading. Negative work -- also known as eccentric (correctly pronounced: ik sen' trik) work -- occurs as the muscle is lengthening. Rather than merely dropping a barbell -- which requires no effort whatsoever -- the barbell is lowered under control and the muscle is said to uncontract.

Negative work is extremely important, most particularly for early-stage rehabilitation. Grossly debilitated subjects -- who may at first be incapable of lifting the weight of their injured limb -- are often capable of lowering said limb and experiencing dramatic improvement to regain functional competence.

Without the potential for Negative Work, several other requirements are obviated.

Stretching Stretching is the act of pulling a muscle and/or a joint into a position that momentarily exceeds its active range of motion. This is performed purposefully to increase flexibility of the muscle and/or the joint.

True muscular stretching as a result of exercise occurs only when a muscle is pulled -- by another body part, by another person, or by the negative work of an exercise machine -- beyond that position obtainable by the volitional contraction of that muscle's antagonist musculature. Without negative work in an exercise machine, any stretching due to the back pressure supplied by the machine is missing.

Prestretching Prestretching is a matter altogether different from Stretching. It is a short-range, sudden movement in the opposite direction of positive contraction. This brief twitch invokes a reflex arc that alarms the muscle to activate a higher contraction intensity. This technique, properly performed, is then immediately followed by a smooth, continuous muscular contraction of higher intensity. Without the potential for Negative Work, the potential for any prestretch due to the machine is impossible.

Resistance in the Position of Full Muscular Contraction In most exercises, the target musculature encounters no meaningful resistance in the fully-contracted position. In the typical squat or leg press, for example, the bones are aligned at said position and therefore support the entire load, minus some minor balancing performed by the muscles. Therefore, with these exercises, there is no resistance at the position of full muscular contraction.

But with a rotary-form exercise such as a leg extension, the potential exists for meaningful resistance once the leg is straightened with the muscles, therefore, fully contracted. However, this opportunity is obviated without the presence of Negative Work potential.

Unrestricted Speed of Movement Although the first nine requirements of The Ten Requirements of Full-Range Exercise are secure and not really subject to debate, the tenth requirement is not so secure. It cannot be proved that an exercise machine should be designed to provide an unrestricted speed of motion. This is to say that equipment should not be so designed as to force the user to conform to an arbitrarily selected movement speed. Note that, as applied, the word unrestricted is not synonymous with unlimited.

Commentary

Story #1 In the early 1980s, I briefly managed an advertising campaign for Nautilus that ran ads in The Physician and Sportsmedicine. The magazine's advertising editor phoned me and complained that I could not use the famous Nautilus slogan: Nautilus . . . the only source of Full-Range Exercise. The advertising editor, of course, was not aware that Nautilus had used this slogan for several years in many advertisements throughout the industry. He also was not aware that Full-Range Exercise was defined by Arthur as exercise in which the Ten Requirements of Full-Range Exercise were complete.

I battled it out with this editor for several weeks. I sent him previous advertisements run in other magazines. I sent him Ellington Darden's books wherein the Ten Requirements were detailed. Nevertheless, he never gave in to my arguments. Actually, I suspect that I was arguing not with the editor, but with his masters -- unseen, supposed experts who resented nonacademics defining Full-Range Exercise. Eventually I upped the ante with yet more superfluous pedantics. Showing a patient in therapy on a Nautilus Leg Extension, I supplied copy that said in effect:

Only Nautilus provides the following protocol choices:

The editor phoned to have me explain all of these terms and to convince him that Nautilus equipment did indeed supply these concepts and protocols.

Arthur subsequently saw the ad copy and chided me for this unnecessary gobbledygook. He said, "Ken, just say that Nautilus is the only source of Full-Range Exercise." I then explained the dilemma regarding our pet slogan and the magazine editor. Arthur became furious toward the editor, but also realized that I, indeed, had followed the Nautilus format and that my copy was necessary under the circumstances.

Story #2 During the middle 1970s, we at Nautilus were very serious (probably too serious) about The Ten Requirements of Full-Range Exercise. For a while, Arthur went through a phase -- and I and Ellington Darden and others followed suit -- that if an exercise were truly full-range, then compound movements were, therefore, unnecessary.

Vince Bocchicchio took Arthur's momentary tangent as fact and opened a facility that consisted of only rotary Nautilus exercises. As many readers already know, Vince conveyed his slow training style to me with the notion that it was only for rotary movement. Thus, the idealism was fixation among several of us. I understand that Vince owned only rotary, single-joint Nautilus machines for many years thereafter.

Note that several terms are related. According to the Ten Requirements, only a rotary exercise machine is ideal, and this device is a single-joint or simple movement. Therefore, simple = single-joint = rotary = full-range = ideal.

Oppositely, note: compound = multiple-joint = linear = non-full-range = non-ideal.

Criticism

The Ten Requirements of Full-Range Exercise are now archaic. Taken in proper context, however, they remain remarkably valuable. I believe it important that every SuperSlow instructor read and study the chapter entitled Full-Range Exercise in The Nautilus Book by Ellington Darden, PhD. Ellington's book does provide a broader discussion that is unnecessary for me to rehash. Master this material to develop a working knowledge of the terms and arguments, but also to compare my following criticisms of the Ten Requirements. Also note that the Ten Requirements still provide a somewhat reasonable analysis of the comparative value of exercise equipment. Note the comparison table published on page 8 of The Exercise Standard, Volume 1, Issue 4 (October 1993).

Rotary Resistance On page 69 of the SuperSlow Technical Manual is a side bar entitled Torque vs Rotary Resistance. Without a total rehash of that material, I herein state only that 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 magnitude and lever length. Torque, as you might now appreciate, is a foreign concept to most people, including some scientists and doctors. Furthermore, I indeed appreciate that the use of torque by Arthur in his efforts to market and promote Nautilus would have proved a difficult impasse. Rotary Resistance, though semantically incorrect, is a better marketing word for laymen.

Rotary Resistance is not simply an issue of incorrect semantics. It is also conceptually incorrect in another way. In the early 1970s, Arthur Jones used the term Omnidirectional Resistance. Through study of what Arthur and company meant by Omnidirectional Resistance, we find an important flaw in his intuition regarding rotary resistance.

Referring to several early Nautilus catalogs and articles, it beomes evident that Arthur gradually evolved the Ten Requirements. For example, in one 1973 Nautilus Catalog, he listed only seven requirements:

Eventually, Omnidirectional Resistance was dropped. I do not know why it was dropped; However, the term omnidirectional is semantically incorrect when applied to an arc that sweeps through a two-dimensional plane. Omnidirectional means, literally, all directions. And its concept demands a three dimensional reference. For example, gravity is omnidirectional at the earth's gravitational center. The earth should therefore be hollow, since gravity is directed in all directions away from its center.

We at Nautilus continued to apply our inconsistent concept of omnidirectional though it was somewhat redundant with rotary resistance. What we were saying was this:

Perform a standing barbell curl, thus flexing your elbows FROM a straight-elbows position with both upper and lower arm bones vertical TO a bent-elbows position whereby your upper arms are roughly vertical and your lower arms are angled from the vertical at about 30 degrees.

Note that as you begin the lift, your arms move directly forward while the resistance from gravity is downward. As you bend your arms, the barbell moves less forward and more upward. Once past the halfway point at 90 degrees elbow flexion, the barbell begins to move less upward and more toward your torso. Only at the 90 degrees position did your muscles lift the barbell directly against the vertical and downward resistance of gravity.

Rotary-form exercise is omnidirectional [Orthogonal was the word of choice] in the sense that the resistance is eternally in direct opposition to your arc of movement. It is always at a right angle to the bone or body part directly powered by the targeted muscles.

Contrary to this point of reference, I now realize that it does not matter that gravity is unidirectional in the above example. The movement remains rotary because of the ligamentous constraints in the elbows. Torque is effected because of these constraints, although the instantaneous application of force by gravity to the moving bones is linear. The same thing occurs in a rotary-form Nautilus machine. It is proper to say that an exercise such as a Pullover provides rotary-form motion; However, its instantaneous resistance is unidirectional, as is a barbell. The pullover does not imposed rotation about the shoulder, unless its movement arm is a coupled movement arm (See the next article).

Direct Resistance This concept remains valid.

Variable Resistance Every exercise machine under the sun varies. The real problem is that almost all equipment varies improperly, including most current MedX® and Nautilus machines today. To design equipment which does not vary the load to the target musculature -- that is, to set all variables to zero -- one must remove all cam effects, movement arm imbalances, and bodytorque. This occurs only with great study and care and is not usually desirable.

Balanced Resistance This concept remains valid. Properly balanced resistance, though, can only occur once the ideal speed of motion is roughly decided. MedX and Nautilus often determine their curves based on the popular vote of customers who know less about the ideal requirements than the pollsters.

Positive Work This concept remains valid

Negative Work This concept remains valid.

Stretching This concept remains valid, although an emphasis on stretching is often misguided and potentially harmful to joints. Please read my specific caveats regarding stretching on pages 86-87 of The SuperSlow Technical Manual.

Prestretching This concept is invalid. Prestretching only encourages a host of other form discrepancies and does not elicit any more intense muscular contraction or deeper inroading than the thorough inroading technique detailed on pages 17-25 of The SuperSlow Technical Manual. Please also read the details regarding our (Nautilus') prior fascination with prestretch on pages 13 and 21-23.

Resistance in the Position of Full Muscular Contraction This concept remains valid.

Unrestricted Speed of Motion I am just about ready to strike this requirement entirely. I believe that some kind of escapement mechanism -- like that used in clocks -- to narrow the speed range might be helpful to most, if not all, subjects. Early isokinetic attempts to control speed of motion were friction-based and devoid of negative work -- less efficient than a brick tied your limb. Although I remain adamantly opposed to isokinetic philosophy that suggests train fast to be fast and muscle fiber typing, some kind of speed-dictating device may be the ultimate inroading tool.

Progressing toward this end, I see electromagnetics as the next efficiency beyond mechanical resistance modulation. Better yet is manually-resisted exercise. Manually-resisted exercise is very hard on the instructor and might be enhanced greatly by a line of equipment providing two stations -- one for the instructor whereby he works levers to provide the perfect touch to the subject -- the other for the subject where he performs movement in accordance with muscular function against the resistance modulated with ease through the levers by the instructor. Potentially better yet and most ideal is the servo-driven device that merely moves the movement arm positively and negatively. The subject attempts to increase its positive speed and decrease its negative within the guidelines of safe force and with an inroad depth far deeper and quicker than any tool yet devised.