The Colorado Experiment

The Colorado Experiment occurred in May of 1973 at Colorado State University. The purpose of the experiment was to produce a high level of muscular development by training Casey Viator every other day, or 14 times in 28 days, in a monitored university setup.

Nautilus-inventor Arthur Jones directly trained Casey for every single workout. The training was intense, dynamic, and also entailed a negative-only rep style on 50 percent of the exercises.

Colorado Experiment

During the very first week alone, Viator got 27.25 pounds of strong muscle mass. Repeat: That’s 27.25 pounds of muscle in 7 days or an average of 3.9 extra pounds of muscle each day. The realities show that throughout week 1, Viator acquired 20.25 pounds of body weight and also shed 7 extra pounds of fat, for an overall of 27.25 pounds of muscular tissue mass.

Viator’s general muscular tissue mass gain in 28 days was 63.21 extra pounds. That was an average muscular tissue mass rise of 2.26 pounds each day.

There are a lot of conjectures, accusations, as well as outright urban myths about the Colorado Experiment. Some are funny, some have to do with shock, as well as others are malicious. I’ll resolve every one of them below, however, the inarguable reality is, that Casey Viator gained a massive quantity of muscle in a very short time.


The month adhering to the Colorado Experiment I was at the AAU Mr. America contest in Williamsport, Pennsylvania, when Arthur Jones and Casey Viator released initial details concerning the outcomes.

In July of 1973, Jones hired me to come to be Director of Research for Nautilus Sports/Medical Industries, and I operated in that ability for 20 years. Among my very first jobs at Nautilus was to become very aware of the Colorado Experiment. Jones had a folder that contained all the exercise routines and also Jones’s spouse, Liza, had a notepad that she used to tape-record Viator’s everyday food intake. I still have copies of that material.

All the appropriate information was divided and also set up. Nautilus printed and distributed thousands of brochures on the Colorado Experiment. I published the cause in numerous of my books, as well as three or 4 various other authors who did the same.

My very own background with Viator goes back some 4 years earlier than the Colorado Experiment. I first met Casey in a bodybuilding competition in Texas in 1969 as well as competed against him for the following two years. While at the Nautilus head office in Lake Helen, Florida, from 1973 to 1980, I trained as well as photographed Casey countless times, specifically in preparation for the 1978 NABBA Mr. Universe competition.

Worrying Jones, I fulfilled him in August of 1970 at the AAU Mr. USA competition in New Orleans as well as saw him in Lake Helen, Florida, several times over the following 3 years. I kept in regular contact with Jones up until he passed away in 2007.

Currently, allow’s to get to the real realities, numbers, and also fiction of the Colorado Experiment.


Colorado Experiment

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Before I address several of the fiction bordering the Colorado Experiment, right here are the essential facts you need to understand:

Truth– On April 30, 1973, pre-experiment dimensions were taken of Casey Viator’s body structure by Dr. James Johnson, Associate Professor, Department of Radiology, Colorado State University.

Truth– Casey Viator, age 21, at a height of 5 feet 8 inches, had a starting weight of 166.87 pounds. His percentage of body fat, as measured by the “potassium whole body counter,” was 13.8 percent.

Truth– The experiment was carried out from May 1, 1973, to May 29, 1973, for an elapsed duration of 28 days.

Fact– No unique food supplements were utilized. No development medications or steroids were engaged. A sensibly well-balanced diet regimen was eaten, with Viator eating 6 dishes per day.

Fact– The last week of April 1973, 20 items of Nautilus equipment, consisting of some negative-type models, were provided and also moved into Dr. Elliot Plese’s Exercise Physiology Laboratory at Colorado State University in Fort Collins, Colorado.

Fact– Arthur Jones and also Casey Viator flew into Fort Collins and remained till the completion of May.

Reality– Arthur Jones personally educated Casey as well as pushed him to his limitation on each exercise. Viator’s routines averaged 12 workouts. Each workout balanced 33.6 mins.

Fact– Viator’s finishing body weight was 212.15 extra pounds with 2.47 percent body fat. That was an increase of 45.28 pounds of body weight, which included a loss of 17.93 pounds of fat.

Fact– During the very first week alone, Viator gained 27.25 pounds of solid muscle mass. Repeat: That’s 27.25 pounds of muscle in 7 days, practically 4 pounds of muscle daily. The realities reveal that throughout week 1, Viator acquired 20.25 pounds of body weight and also lost 7 extra pounds of fat, for a total of 27.25 pounds of muscular tissue mass.

Fact– Viator’s general muscle mass gain in 28 days was 63.21 extra pounds. That was a typical muscle mass rise of 2.26 pounds per day.



To prevent any kind of misconception, Jones took care to constantly keep in mind that Viator’s outcomes were anything but average. They were extraordinary most especially since Viator was an extremely talented athlete, with lengthy muscle stomaches throughout his body.

Jones additionally explained that 2 years earlier Viator won the 1971 AAU Mr. America, weighing 218 pounds. After winning the competition, Viator took a while off from training as well as returned in December of 1972, weighing 200.5 pounds. In early January of 1973, Viator was associated with a severe accident involving a wire-extrusion maker and lost a lot of the little finger on his right-hand man. After that, he nearly passed away from an allergic reaction to an anti-tetanus injection.

Because of this, from January through April of 1973, Viator did no training. The majority of the time he was depressed as well as he had few cravings. His muscle mass atrophied, as well as he lost 33.63 pounds, with 18.75 of the pounds being attributed to the near-fatal shot. Some, perhaps most, of Viator’s success from the Colorado Experiment was that he was rebuilding muscle mass that he had already constructed 2 years previously.


Casey was out of steroids throughout the Colorado Experiment. Arthur Jones was clearly against anabolic medications of any type kind and made this clear in all his writings. He noted in his report on the Colorado Experiment that “the use of so-called growth medicines (steroids) is neither essential nor desirable.”.

In anticipation that Casey might be implicated in taking medicines during the experiment, Arthur hired the toughest person available to watch Casey 24/7. That was this man? It was Tom Wood, and also I’ve consulted with Tom numerous times about his participation in the Colorado Experiment as well as he verifies Casey did not take anabolic steroids during the 28-day study.


Arthur did not count on force-feeding or “bulking” diet regimens. A daily food diary was kept for Casey as well as whatever he consumed was meticulously recorded. I directly examined this diary and calculated the complete number of day-to-day calories Casey ingested. He never ate greater than 5,000 calories and also a lot of days were closer to 4,000, which is very little considering the brutal exercises he was experiencing.


Arthur employed instead flat lighting, rather than contrast illumination since he wanted to affect the training and medical professions more than the bodybuilding world. Extreme muscularity would have been a turn-off on the market that Jones most intended to affect.

I saw Casey quickly after the conclusion of the Colorado Experiment as well as he took off his t-shirt and did some postures. His physique face to face was considerably more muscular and torn, contrasted to the monotony that was shown in the after photographs.

Additionally, Jones was a precise manager of area measurements, yet he made use of these parameters to satisfy his inquisitiveness and this information was not released. However, quickly after the Colorado Experiment, I asked Jones to allow me to see Casey’s before-and-after measurements. The third time I bothered him for the numbers, here’s what Arthur reported:

” Casey included 2-1/8 inches on each got arm, 5-7/8 inches on his chest, 2 inches on his midsection, and also 3 inches on each thigh.”– Arthur Jones.

Taking into consideration those dimensions, in addition to the level lights of the comparison photos, after that a gain of 45.28 extra pounds of body weight, as well as 63.21 extra pounds of muscular tissue, are, in my sight, much more probable.


Casey had what I considered to be one-in-a-million genes for muscle building. So replicating the results would certainly be very hard, specifically considering Viator was primarily restoring muscle he had formerly built. Although they don’t have the genes of Casey, I’ve placed several above-average men with programs similar to the Colorado Experiment.


Colorado Experiment

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This workout uses a horizontal chin-up bar. You also require a durable bench. Perform the positive work by stepping up on the bench and the adverse work by decreasing your body with your arms. Take an overhand grasp on the bench, with your hands roughly 12 inches larger than your shoulders. Climb right into the leading position and location the bar behind your neck. Your elbow joints should be down and also back. Hold the leading position snugly and alleviate your feet off the bench. Lower your body gradually in 6-8 secs. At the bottom, stretch briefly, as well as climb back promptly to the top, and begin one more negative rep. You ought to feel this workout deeply in your arms, lats, as well as shoulders.

Note: It’s doubtful that you’ll need to include resistance with a weight belt. If you can achieve at least 6 repetitions the very first time you try it, you’ll undoubtedly be a prime suspect for development.


You require one or two watchmen to raise the bar. Load weights on the supports of a flat bench with 30 percent more resistance than you regularly manage for 6-8 reps. Set up unemployed and also realize the barbell with your hands positioned somewhat wider than your shoulders. Have the spotters raise the bar into the starting placement. The barbell should be straight over your shoulders. Lower bench gradually in 4 to 8 secs to your upper body. When you touch your chest, the watchman raises the bar back to the leading setting. The watchmen raise 80 percent of the resistance, while you lead the barbell appropriately to the top. As they move the resistance securely in your hands, take a deep breath, as well as proceed with the slow downsides for the required repeating.


I like an EZ-Curl to a straight bar because it eases excess torque from the wrists and allows outside rotation of the hummers, which is a safer setting for the shoulders. Place a packed EZ-Curl bar on the floor ahead end of a strong bench. Lie face-up on the bench, with you avoid the end. Reach expenses and also down and understand the EZ-Curl bar with narrow hand spacing. Support your reduced body, curve your back somewhat, and also pull the bar up and also over your torso to your upper body. The bar should be resting across your breast on your sternum. Relocate the bench back over your head towards the floor. Stretch your lats as well as shoulders gradually near the bottom. Do not align your arms. Keep them curved throughout both the favorable as well as adverse phases.

Keep in mind: The included drawing muscle mass has the potential to be large and solid. Do not hesitate at some point to make use of 150 pounds or even more on this exercise. Yet take care initially on enhancing the series of activities; do so progressively.


Position your feet to close together under a packed weight. Bend over as well as understand the weights with a surreptitious grip. An underhand grip, contrasted with an overhand hold, places your arms in the greatest position. Your hands ought to be 4-6 inches apart. Your torso needs to remain alongside the floor. Maintain a minor bend in your knees to lower the tension on your reduced back and also hamstrings. Pull the barbell as much as your waistline. Time out in the leading placement and try to pinch your shoulder blades with each other. Reduced gradually to the bottom and stretched.


Lots a barbell with 30 percent a lot more resistance than you take care of regularly for 10 reps. Have a spotter at both ends of the weights lift the resistance to the top position of the crinkle. Understand bench with a shoulder-width surreptitious grasp. Support your elbows firmly versus the sides of your midsection as well as maintain them there throughout the exercise. Reduced bench gradually in 4 to 8 seconds to the bottom. As quickly as you reach the bottom, the watchman raises the bar back to the top. The spotters require to execute the favorable, lifting phase promptly as well as the transfer has to be taken care of efficiently. Once again, it’s your job to lower slowly in control.

Note: The arms crinkle with weights was just one of Arthur Jones’s all-time favorite workouts which’s why he typically included it in his weights routines. When Jones was in the most effective shape of his life, he evaluated 200 extra pounds. He informed me that at that weight he was able to curl 180-pound weights for 10 solid repeatings. That took some extremely strong biceps muscular tissues.


Grasp a horizontal bar with a shoulder-width, surreptitious grip. Hang at arm’s length and bend your knees as well as cross your ankles. You need to go back to this dead-hang placement each time you reduced your body. Pull your head and breast toward the bench. Once your chin is over the bench, move your arms down as well as press your shoulder blades with each other. Reduced your body smoothly to the dead-hang position. Repeat for maximum repetitions.


Once more, utilize a tough bench to climb right into the leading position. The suggestion is to do the positive by stepping up into the leading setting and the negative work with your arms. Location the bench directly under a horizontal bar. Climb into the top setting with your chin over the bench. Hold on to the bench with a surreptitious grasp and also space your hands shoulder-width apart. Eliminate your feet from the chair or bench. Reduced your body gradually in 6-8 secs. See to it you come completely down to a dead hang. Climb up back rapidly into the leading setting.

Note: To add weight, use a weight belt as well as connect a suitable weight on the chain. Some students can utilize from 60 to 100 pounds of connected weight on this workout.

Colorado Experiment

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Mount the dip bars as well as prolong your arms. Bend your knees and also cross your ankle joints. Lower your body slowly by flexing your joints up until your arms dip just listed below your elbow joints. Push back to the beginning position. When you can successfully do 10 or even more dips, utilize a weight belt to include resistance.


The majority of students will certainly need additional resistance added to their body weight with a weight belt. Climb into the top position of a dip station as well as correct your arms. Eliminate your feet from the active support as well as maintain your body. Bend your arms and reduced your body gradually in 6-8 seconds. Feel the stretch by going simply listed below where your upper arms are alongside the floor, which shouldn’t hurt. Climb back to the starting placement as well as correct your arms.

Keep in mind: Dips were among Casey Viator’s preferred exercises. He can do greater than 30 regular dips in strict form, and I’ve seen him do 10 negative-only dips with 270 extra pounds attached to his body.


Maintain yourself under the lat machine as well as understand the above bar with an underhand grasp. Your hands must be about shoulder-width apart. Pull the bench efficiently to your upper breast. Pause. Return gradually to the stretched setting. Repeat for 7 to 10 repetitions.

Note: Arthur Jones liked applying the lat-machine pulldown immediately after the bent-armed shirt– and also he utilized this mix regularly in his workouts.


Realize a dumbbell in each hand and stand. Lean onward at the waist approximately 20 degrees from vertical. Stay in this leaning-forward placement throughout the exercise. Lock your elbows and wrists and also maintain them secured throughout the exercise. All the action should be around your shoulder joints. Elevate your arms sidewards. Time out briefly when the pinheads are somewhat over straight. See to it your elbows are somewhat bent. Lower the pinheads gradually to your sides.


You need a watchman to do the lifting portion of this exercise. Place 30 percent a lot more resistance on the weight stack than you consistently utilize for 10 reps. Lie facedown on the device with your knees on the pad side closest to the moving arm. Make sure your knees are in line with the axis of rotation of the maker. Understand the takes care provided to steady your top body. The spotter helps you lift the activity arm to the gotten placement. Pause and make a smooth transfer of the resistance to your acquired hamstring muscles. Lower the resistance very slowly in 4 to 8 seconds. Make use of the watchman to get back to the top placement and also proceed with the adverse leg curls up until you can no more do a minimum of a 3-second descent.


You need a watchman to do the lifting part of this exercise. Location 30 percent much more resistance on the equipment than you regularly do for 10 repetitions. Sit in the maker as well as place your feet as well as ankles behind the roller pads. Straighten your knees with the axis of rotation of the moving arm. Lean back and stabilize your top body by understanding the manages or the sides of the seat. The watchman helps you lift the activity arm right into the contracted top placement and make a smooth transfer of the weight. You lower the weight in 4 to 8 secs back to the beginning setting. Quickly, the spotter gets hold of the activity arm near the bottom and also helps you rapidly get it back to the top placement. Continue performing reps up until you can no longer manage a 3-second adverse.

Colorado Experiment

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Hold a dumbbell at one end with both hands. Press the dumbbell expenses. Position your elbows in limited and near your ears throughout the exercise. Bend the elbows and lower the dumbbell gradually behind your head. Do not relocate your elbows. Just your lower arms and also hands must move. Beware in the bottom position, where the triceps are extended and susceptible to strains. Move-in and out of the bottom position progressively with no jerks. Press the dumbbell efficiently back to the extended placement.


Stand and place a barbell in front of your shoulders with your hands slightly broader than your shoulders. Keep your feet carry size apart. Press the barbell expenses smoothly. Do not pound right into the lockout. Maintain a mild bend in your joints at the top, which will maintain the active muscle mass loaded. Reduced the weight under control (2 to 3 secs) to your shoulders. Do not jump the weights off your shoulders near the bottom. Make a smooth turn-around.


Take an overhand grip on a barbell and stand erect. Your hands must be somewhat bigger apart than your shoulders, and the bench needs to be touching your upper legs. Relax your shoulders onward as well as downward as far as conveniently possible. Shrug your shoulders upward as high as possible. Time out briefly at the top. Reduced gradually to the stretched placement.


Place a barbell on a squat rack as well as load it with a suitable weight. Position the bench behind your neck throughout your trapezius muscular tissues, and also hold the bar in place with your hands. If the bench cuts into your skin, pad it gently by wrapping a towel around the bar. Raise the bench off the rack and move back one step. Place your feet shoulder-width apart, toes angled slightly outside. Maintain your upper-body muscle mass rigid and your upper body as upright as possible throughout this exercise. Bend your hips and also knees and smoothly come down to a placement whereby your hamstrings firmly come in contact with your calves. Without jumping or dropping in the bottom placement, gradually make the turn-around from negative to favorable. Lift the weights back to the top setting.


Even though this workout is called a stiff-legged deadlift, it must be carried out with a small bend in your knees. This safeguards the reduced back and also the hamstrings. Stand overweight, bend your hips and knees, and also understand the bar with an overhand grasp with your hands shoulder-width apart. Expand your hips as well as knees and also lift the barbell smoothly to a standing placement. Lower the barbell efficiently while maintaining a minor bend in your knees. Touch the floor gently with the weights, however, do not pull up. Lift the barbell smoothly to the standing placement. Repeat for 7 to 10 reps.

Note: Ease into the stiff-legged deadlift, especially if you have tenderness or discomfort in your lower back or tight hamstrings.


Understand weights with a palms-up grip. Take a seat as well as relax your forearms on your thighs and also the backs of your hands against your knees. Lean ahead until the angle between your arms as well as lower arms is less than 90 degrees. This placement enables you to separate your forearms better. Crinkle your hands smoothly by getting your lower arm muscle mass. Time out briefly. Reduced the barbell gradually.