How to build 63 pounds of muscle in 28 days: The infamous Colorado Experiment
Left: Casey Viator on 5/1/1973,
Right: Casey Viator on 5/29/1973 Casey had increased his muscle mass by 63.21 pounds in 4 weeks with 14 short workouts. During this process, he gained 5.4 inches on each arm, 15 inches on his chest and 7.5 inches on each thigh.
Is it possible to gain 63 pounds of muscle in less than a month? What about 15 pounds of muscle within 22 days? By any standard, such results would be phenomenal, but few people believe such feats are feasible.
And yet Arthur Jones, the inventor of the Nautilus machines, claimed in the early seventies that this was possible through the High Intensity Training (HIT) he developed. He even claimed to have scientific evidence to support his claim.
So what exactly happened during the Colorado experiment conducted by Jones - and is he telling the truth? Did strength enthusiasts sell themselves short by setting their muscle gain goals too low? After all, such training must be worth a try if it can build 15 to 63 pounds of muscle in a month.
The background to the experiment
Jones' goal in conducting this experiment was to gain publicity and credibility for his version of High Intensity Training. As described by Randy Roach in 'Muscle, Smoke and Mirrors', Jones was promoting a style of training that many in the bodybuilding industry were uncomfortable with. Jones insisted that high intensity was necessary for optimal muscle building and promised that short sessions of high intensity training could produce amazing results.
An anecdote from the seventies that was often told to demonstrate the intensity of Jones' training was that the famous bodybuilding champion Arnold Schwarzenegger could not complete a training session with Arthur Jones because it was too hard.
For the Colorado experiment, Jones teamed up with Dr. Elliot Plese of Colorado State University's Department of Physical Education Laboratory to conduct a month-long study. The goals defined at the beginning of the study were as follows:
- To prove that very short training sessions are capable of producing rapid and extensive gains in muscle mass and strength.
- That nothing but a sensible diet is necessary.
- That so-called "growth drugs" (aka steroids) are not necessary.
Jones was a very brash and often unpopular voice in the fitness industry. He had a poor opinion of the general fitness consensus and was not afraid to say so. In numerous interviews, seminars and publications, he regularly attacked others in the fitness industry for using false claims and unreasonable training principles.
One example was the use of steroids. Jones believed that steroids and other performance-enhancing substances hinder rather than promote muscle growth and strength. In many ways, he was a voice for those who were uncomfortable with the trend toward steroid use in training that was prevalent in the United States and most of the Western world in the mid-20th century. What really mattered to Jones was genetics and training. It couldn't be just any old training, of course - it had to be intense. Once such rules were applied, the results would follow - that was his promise.
The experiment
In May 1973, Arthur Jones and Casey Viator began their training under the watchful eye of Dr. Plese. Everything they did was monitored - from their training to their dietary regimen. It was to be a month of training, eating, recovery and not much else.
The following is an example of a normal training session for Casey:
- Leg press: 750 pounds for 20 reps
- Leg extensions: 225 pounds for 20 reps
- Squats: 502 pounds for 13 reps
- Leg curls 175 pounds for 12 reps
- Single-leg calf raises with 40 pounds in one hand for 15 reps (rest 2 minutes)
- Pullovers: 290 pounds for 11 reps
- Latissimus isolations (https://www.youtube.com/watch?v=a-vb6U6G82w): 200 pounds for 10 reps
- Rowing machine: 200 pounds for 10 reps
- Neck pulldowns: 210 pounds for 10 reps (2 minutes rest)
- Dumbbell side raises with outstretched arms: 40 pounds for 9 reps
- Neck press: 185 pounds for 10 repetitions
- Bicep curls on the machine: 110 pounds for 8 reps
- Pull-ups with your own body weight: 12 repetitions
- Tricep presses: 125 pounds for 9 reps
- Dips on parallel bars with your own body weight: 22 repetitions
The exercises were performed one at a time on Jones Nautilus machines or MedX machines. Each set was performed to muscle failure and unless otherwise specified above, there were no rests between exercises. Jones once wrote the following about his training philosophy:
"High intensity training is not easy....the workouts are short - and they must be short - but there is an obvious natural tendency in most exercisers to hold back."
In his 1999 autobiography, Viator described how Jones approached Casey's workouts and used tricks, including open insults, to make sure Casey didn't hold back and really gave it his all. So not only was the training intense - it was also overseen by a coach who was lovingly strict.
What were the results?
In September of that year, Jones published the results in Ironman magazine. Here's an abridged version.
The Colorado Experiment by Arthur Jones
The following is a brief, preliminary report on an experiment conducted at Colorado State University in May of 1973.
Location . . . Department of Physical Education, Colorado State University, Fort Collins, Colorado.
Supervisor . . . Dr. Elliott Plese, Director of Exercise Physiology Lab, Colorado State University.
Data ... May 1, 1973 to May 29, 1973 for one subject (Casey Viator), a duration of 28 days . . . and May 23, 1973 for the second subject (Arthur Jones), a duration of 22 days ...
RESULTS:
First subject (Casey Viator), 28 days
- Gain in body weight........45.28 pounds
- Loss of body fat.................17.93 pounds
- Muscle gains......................63.21 pounds
Second subject (Arthur Jones), 22 days
- Body weight gain........13.62 pounds
- Loss of body fat...................1.82 pounds
- Muscle gains.......................15.44 pounds
The results were nothing short of spectacular, but Jones was quick to qualify the success:
It should be clear that none of the subjects were "average" subjects, and one cannot conclude from the results that individuals with average or below-average potential will achieve the same results with a similar training program.
Casey Viator trained regularly with barbells and other training equipment for several years until June 1970, when he placed third in the Mr. America competition. He then trained with barbells and Nautilus equipment until June 1971, when he won the Mr. America competition. From September 1971 to September 1972, he trained primarily with Nautilus equipment and performed only limited barbell training, which consisted primarily of barbell squats. From September 1972 to December 23, 1972, he trained exclusively with Nautilus equipment and limited his exercises to pure negative repetitions. At the end of this phase, he weighed 200.5 pounds.
In January 1973, he had a serious accident at work in which he almost completely lost a finger and nearly died from an allergic reaction to a tetanus shot. For about 4 months from early January to April 1973, he did not exercise at all and since his activity level was low, he lost about 33.63 pounds, losing 18.75 as a direct result of the accident and the near-fatal injection. Thus, his weight loss through 4 months off exercise was only 14.88 pounds - less than a pound a week.
The second subject (the author, Arthur Jones) had been exercising relatively irregularly for 34 years...and at one point about 19 years ago had reached a body weight of 205 pounds.
The author had not trained at all for about 4 years until late November 1972, and then trained regularly with a purely negative training program for about 6 weeks. He stopped training completely in early January and did not start training again until the Colorado experiment began.
The author's body weight had fluctuated between 145 and 160 pounds over the past 10 years, reaching 190 pounds about 4 years before the start of the Colorado experiment after a six-month period of continuous training.
Both subjects have therefore shown in the past that they have an above-average potential for building muscle mass, and both subjects built up previously achieved levels of muscle mass again.
Despite the predisposition of both men to build muscle, Jones apparently had no doubt that his form of training was effective. He even claimed that both men had achieved the aforementioned massive gains in muscle mass with training sessions lasting just 25 minutes.
Was the experiment serious?
Unsurprisingly, given the alleged results, doubts about the Colorado experiment quickly arose. After three decades, three major points of criticism have emerged.
1) Replicability:
The Colorado Experiment has never been replicated apart from individual experiments by interested exercisers. The sole purpose of the experiment was to gain scientific support for the High Intensity Training concept, and the fact that no one was able to replicate the results - or even a fraction of them - in a large-scale study has compromised the credibility of Jones' results. Jones conducted another experiment, the West Point Experiment, in which he used his form of training, but it has proven difficult to find the exact results of this study.
2) Biased selection of subjects
Both Casey and Arthur had trained with weights before. Viator is known for his amazing genetics and good predisposition to building muscle. Jones had also built a solid 190-pound body years before the experiment. Many have speculated that the gains both men achieved were a result of muscle memory (a physiological phenomenon that makes it easier to rebuild muscle and strength you once had).
3) Dirty tricks
This is perhaps the most common accusation leveled at the creators of the Colorado experiment. Prior to the experiment, Casey had lost over 40 pounds due to an allergic reaction to a tetanus shot. Combined with such a huge loss in body weight, Casey was only eating 800 kcal per day a month before the experiment began. This has led many people to believe that Casey's astonishing weight gain was the result of a rebound effect and that he merely regained his normal mass.
Other critics of the experiment suggest that Casey used steroids during the experiment - something he vehemently denied until his death in 2013 - or that Jones manipulated the results before publication.
So was the Colorado experiment a hoax?
That's harder to say. Jones was very open when it came to Casey's potential and the unique position the two men found themselves in. However, there is another part of the story that is often forgotten.
If we go back to Jones' Ironman article, the high intensity training guru also noted the following:
Several members of the Denver Broncos professional football team visited the lab to observe the workouts and then began training in an identical manner during the final two weeks of the experiment...after the experiment, the Broncos ordered several Nautilus machines and drastically scaled back their previous training regimen.
And while we were training in Colorado, members of several other pro football teams were training at our facility in Florida...in an identical fashion with three short workouts per week and only one set of about a dozen exercises with heavy emphasis on the negative phase of the workout.
Results?
One member of a Canadian pro team got so strong on pullovers that he performed multiple reps at 675 with good form...after starting at 275 pounds two months earlier.
Lou Ross of the Buffalo Bills built up 20 pounds...improved his already very good 40-yard dash time by two-tenths...improved his jump height by 13.5 inches...and doubled his strength on many exercises. These numbers were provided by the Buffalo Bill coaches who tested Lou before and after two months of Nautilus training in Florida.
Mercury Morris of the World Champion Dolphins surpassed his previous highest weight by 7 pounds and still ran the fastest 40 yards of his life when he was tested...and that was after two months of Nautilus High Intensity Training.
If you want to learn about the true successes of the Colorado Experiment, the latter athletes are probably the best case studies. Casey and Jones knew they would get amazing results from the training, the athletes did not. So there is a possibility that it wasn't all smoke and mirrors after all.
Controversy surrounds the Colorado experiment. Some in the fitness industry cite it as proof that Jones' methods were worth their weight in gold, while others use it as proof that Jones was a trickster. However, as with much else in the fitness industry, ultimately everyone has to know for themselves what they believe and what they don't.