He won several amateur bodybuilding competitions before turning professional in 1979, including the 1976 Mr. America title and the heavyweight division of the 1978 IFBB Mr.
[5][8] Mentzer started bodybuilding when he was 11 years old at a body weight of 95 lb (43 kg) after seeing the men on the covers of several muscle magazines.
In early 1975, however, he resumed training and returned to competition in 1975 at the Mr. America contest, placing third behind Robby Robinson and Roger Callard.
He won the 1977 North America championships in Vancouver, British Columbia, Canada, and competed a week later at the 1977 Mr. Universe in Nîmes, France, placing second to Kal Szkalak.
[5][1] In late 1979, Mentzer won the heavyweight class of the Mr. Olympia, again with a perfect 300 score, but he lost in the overall to Frank Zane (who was awarded his third title) that year.
[11] Mentzer was an Objectivist and insisted that philosophy and bodybuilding are one and the same, stating that "man is an indivisible entity, an integrated unit of mind and body."
Through years of study, observation, knowledge of stress physiology, the most up-to-date scientific information available, and careful use of his reasoning abilities, Mentzer devised and successfully implemented his own theory of bodybuilding.
Mentzer's theories are intended to help a drug-free person achieve his or her full genetic potential within the shortest amount of time.
His recommended diets were well balanced, and he espoused eating from all four food groups, totaling four servings each of high-quality grains and fruits, and two each of dairy and protein daily, all year-round.
[14] While Mike Mentzer served in the United States Air Force, he worked 12-hour shifts, and then followed that up with 'marathon workouts' as was the accepted standard in those days.
Mentzer also learned that Viator almost exclusively worked out with the relatively new Nautilus machines, created and marketed by Arthur Jones in DeLand, Florida.
He emphasized the need to maintain perfectly strict form, move the weights in a slow and controlled manner, work the muscles to complete failure (positive and negative), and avoid overtraining.
He began training clients in a near-experimental manner, evaluating the perfect number of repetitions, exercises, and days of rest to achieve maximum benefits.
Outlined in High-Intensity Training the Mike Mentzer Way, fewer than five working sets were performed each session, and rest was emphasized, calling for 4–7 days of recovery before the next workout.
Most bodybuilding and weightlifting authorities do not take into account the severe nature of the stress imposed by heavy, strenuous resistance exercise carried to the point of positive muscular failure.
Some time later, Mentzer attracted more attention when he introduced Dorian Yates to high-intensity training, and put him through his first series of workouts in the early '90s.
Mentzer stated in the last interview before his death that he did not believe in God "as He is commonly defined", but that "There is what's called a rational view of a creator.
"[17] While in school, Mentzer's father motivated his academic performance by providing him with various kinds of inducements, from a baseball glove to hard cash.
"[5] According to David M. Sears, a friend of Mentzer and an editor and publisher of his Muscles in Minutes book, he stated that:[5] As you know, Mike was a voracious reader of philosophy in college-so that would put him at, say 18 years old, in 1970.
Just as is true with any other context of knowledge, philosophy must be studied in a logically structured order ...In his last interview before his death, Mentzer said he was delighted to get so many phone clients and close personal bodybuilding friends, such as Markus Reinhardt, who had been influenced by him to become Objectivists.
Years later, when Yates won Joe Weider's "Mr. Olympia", he credited Mike's "Heavy Duty" principles for his training.
He was found dead in his apartment, due to heart complications, by his younger brother and fellow bodybuilder Ray Mentzer.