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The Colorado Experiment

The following is a brief, preliminary report of an experiment conducted at Colorado State University in  May of 1973.  A detailed, book-length report titled “Progressive Exercise” well be published in 1974.

LOCATION … Department of Physical Education, Colorado State University, Fort Collins, Colorado.

SUPERVISION . . . Dr. Elliott Plese, Director of Exercises Physiology lab., Colorado State University.

DATES … May 1, 1973 through May 29, 1973 for one subject (Casey Viator),

An elapsed period of 28 days … and may 23, 1973 for the second subject (Arthur Jones), an elapsed period of 22 days.

LEAN BODY-MASS and FAT CONTENTS determinations for both subjects were produced by the WHOLE BODY Counter under the supervision of James E. Johnson, Ph.D., Associate Professor, Department of Radiology and Radiation Biology, Colorado State University.

PURPOSE of the EXPERIMENT … it is the author’s contention that the growth of human muscular tissue is related to the intensity of the exercise; increases in strength and muscle-mass are rapidly produced by very brief and infrequent training … if the intensity of exercise is high enough.

It is the author’s second contention that increasing the amount of raining is neither necessary nor desirable … on the contrary, a large amount of high intensity training will actually reduce the production of strength and muscle-mass increases.

It is the author’s third contention that “negative work” (eccentric contraction) is one of the most important factors involved in exercise performed for the purpose of increasing strength and muscle-mass.

It is the author’s fourth contention that nothing in the way of a special diet is required … so long as a reasonable well-balanced diet is provided.

It is the author’s fifth contention that the use of the so-called “growth drugs” (steroids) is neither necessary nor desirable … on the contrary, repeated tests with animals and double-blind test with human subjects have clearly demonstrated that the use of such drugs is strongly contraindicated.

It is the author’s sixth contention that maximum-possible increases in strength and muscle-mass can be produced only by the use of full range, rotary form, automatically variable, direct resistance.


FULL-RANGE resistance is provided only when the involved body-part is moved through a full range of possible movement against  constant resistance. . . from a starting position of full muscular extension (a “pre-stretched” position) to a finishing position of full muscular contraction.

ROTARY-FORM resistance is an absolute requirement for full-range exercise … since muscular contraction produces a rotary-form movement of the related body-part, it is necessary for the resistance and the body-part to rotate on a common axis.

AUTOMATICALLY-VARIABLE resistance is an absolute requirement for high-intensity exercise … since movement produces changes in unstable strength, it is mecessary for the resistance to vary in proportion to the resulting changes in strength.

DIRECT resistance is also required in order to avoid the limitations imposed by the involvement of smaller, weaker, muscular structures. The resistance must be “directly” imposed against the body-part moved by the muscles being exercised.

Conventional forms of exercise provide none of these requirements; the results beings the … muscles are not worked throughout a full range of possible movement … resistance is limited to an amount the can be moved in the weakest position … little or nothing is done in the way of improving flexibility, since there is no resistance in the fully extended position … and no resistance is provided in the fully contracted position.

Only Nautilus equipment was use in the Colorado Experiment; equipment designed to provide all of the requirements for full range, rotary from, automatically variable, direct resistance.


First subject (Casey Viator), 28 days

Increase in bodyweight … 45.28 pounds

Loss of body-fat ………… 17.93 pounds

Muscular gain …………... 63.21 pounds


Second Subject (Arthur Jones), 22 days

Increase in bodyweight … 45.28 pounds

Loss of body-fat ………... 1.82 pounds

Muscular gain …………... 15.44 pounds

It should be clearly understood that neither of the subjects was an “average” subject, and there is no implication that subjects average or below average potential will all produce equal results from a similar program of the exercises.

Casey Viator has trained on a fairly regular basis for a period of several years; with barbells and other conventional training equipment until June of 1970, at which point he placed third in the Mr. America contest … and with both barbells and Nautilus equipment until June of 1971, when he won the Mr. America contest.

From September of 1971 until September of 1972, he trained primarily with Nautilus equipment … with limited use of a barbell, primarily the performance of barbell squats.

From September of 1972 until December 23, 1972, he trained exclusively with Nautilus equipment … limiting his exercises to “negative only” movements. At the end of tat period of training he weighed 200.5 pounds.

In early January of 1973, he was involved in a serious accident at work and lost most of one finger as a result ... and almost died from and allergic reaction to an antitetanus injection.

For approximately four months, most of January through April of 1973, he did not train at all; and since his level of activity was low, his diet was reduced accordingly. During that period of approximately four months, he lost 33.63 pounds … but 18.75 pounds were lost as a direct result of the accident and the near-fatal injection. So his loss from nearly four months out of training was only 14.88 pounds … less than a pound a week.

The second subject (the author, Arthur Jones) has trained on a very irregular basis for a period of thirty four year … and reached a muscular bodyweight of 205 pounds at one time, nineteen years ago.

The author did no training of any kind for a period of approximately four years until late November of 1972 … and then trained on a fairly regular basis in the “negative only” fashion fro a period of approximately six weeks. Training was ceased entirely in early January of 1973 … and no training was done again until the start of the Colorado Experiment.

The author’s bodyweight has varied from approximately 145 to 160 for the last ten years … briefly reaching a level of 180 at the end of approximately six months of steady training that was concluded four years prior to the start of the Colorado Experiment.

So both of the subjects have demonstrated the potential for greater than average muscular mass ... and both subjects were rebuilding previously-existing levels of muscular size.

A certain percentage of a group of random subjects would undoubtedly produce equal results … a very low percentage might produce better results … a few subjects would produce little or nothing in the way of results … but average results would probably be less than those produced by the two subjects in this experiment. The primary determining factors being (1) individual potential for muscular size, (2) age, (3) general health, and (4) the intensity devoted to the training.

Actually high-intensity training is not easy … the training sessions are brief, indee must be brief, but there is an apparently natural inclination on the part of most subjects to “hold back.” Most exercises are terminated at a point well below an actual point of muscular failure … then, in an effort to compensate for the reduction intensity, the usual practice is to add more exercise to the program.

However, in fact, no amount of additional exercise will compensate for a reduction in the intensity of exercise … and if carried to extremes, which such training frequently is, the subject may actually prevent growth by exceeding the recovery ability of the system.

As stated previously, it is the author’s contention that very rapid and large scale increases will be produced in strength and muscular mass by a very brief program of high-intensity exercise; and it was the purpose of this experiment to demonstrate that such results can be produced in practice as well as in theory.

At the moment, in athletic training circles, it is well accepted that supplemental strength training can be of very great value to athletes involved in any sport. But in practice, a seemingly natural inclination to equate “more” with “better” is actually preventing most athletes from producing the results that could be produced.

Many coaches avoid supplemental strength training because the “don’t have time” … but in fact, very little time is required; if the exercises used are high-intensity exercises properly performed.

Nor is it the author’s contention that using the proper equipment is the entire answer in itself … on the contrary, good results can be produced with a barbell or with conventionally training machines, or with any equipment that provides both negative and positive work. The demonstrated superiority of the Nautilus equipment will be largely wasted if the equipment is improperly used … nautilus equipment is designed to provide a level of intensity that is impossible in any other fashion, but it must be used properly in order to produce maximum-possible results.


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