The Colorado Experiment: When A Bodybuilder Gained 63 Pounds Of Pure Muscle in 28 Days

Training gurus have spent a lot of time explaining how building mass is a slow process that demands a lot of willpower and patience, unless you are a genetic freak or a steroid user. And they’re mostly right. However, in 1973 Arthur Jones created a powerful exception to this rule with his famous Colorado Experiment and set the bodybuilding community on fire. And although many people doubted the validity of the results, the undeniable truth was that they were real and this was easily proven. Here’s what actually happened.

What the Colorado Experiment Taught Us

Arthur Jones, the inventor of the Nautilus exercise equipment which quickly revolutionized gyms around the country, conducted the Colorado Experiment at the Colorado State University in May 1973 in the hope of proving that his radical training methods worked and could produce unprecedented muscular hypertrophy in extremely short period of time. His test subject was bodybuilder Casey Viator, the youngest Mr. America of all time who gained the prestigious title at the age of 19 in 1971 under the training guidance of Jones.

At the beginning of the experiment, Viator, who was 5’8’’ tall, weighed 166.87 lbs or 75.69 kg and had 13.8% body fat. During the next 28 days, Jones personally trained Viator every other day with a brutally intense training regime which emphasized negative repetitions. Each training session included at least 12 exercises performed at high intensity and lasted around 30 minutes. According to Jones’ journal, no food supplements or anabolic s******s were used during the experiment. The bodybuilder ate 6 average-sized meals a day and his macronutrient intake was diligently recorded in a food diary.

In the first week, Viator gained 27.25 lbs or 12.36 kg of pure muscle, which means that he put on 1.76 kg of muscle on average per day! By the end of the 28th day, Viator’s measurements showed that he gained a total of 63.21 lbs or 28.67 kg of lean muscle during the process. These fantastic results were a shock both to those who had already dismissed Jones’ goal as unattainable and those who actually wanted him to succeed!

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Casey Viator Colorado Experiment Before and After Photos

The experiment showed that indeed, very brief workouts can lead to rapid, large scale increases in muscular mass and strength without being accompanied by extreme bulking diets and growth-enhancing drugs.

On the other hand, nobody has been able to successfully repeat it to this very day, which leads us to the conclusion that Casey Viator had exceptional genetics and the average bodybuilder shouldn’t take the unbelievable results of this experiment too seriously or they’ll wind up reaping only frustration. Nevertheless, Arthur Jones and Casey Viator achieved something truly amazing and their legacy will remain an inspiration for many future generations of bodybuilders.

Meanwhile, unless you’re a genetic freak like Viator was, chances are that if you want to accomplish your goals, you’ll have to set realistic expectations and work hard and heavy for a prolonged period of time. Sorry!


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One Response

  1. allan

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