Mike Mentzer's High-Intensity Workout

The principles behind Mike Mentzer's high-intensity workout system.

It was going to be a revolution. For the year between the 1979 and 1980 Mr. Olympias, as high-intensity training rode the crest of its foremost adherent, Mike Mentzer, it seemed on the verge of transforming bodybuilding. Mentzer adopted the HIT philosophy of Arthur Jones and expanded it into his own radical system, named Heavy Duty. Reps got lower, weights got larger. In this article, we examine the rapid rise, faster fall, and enduring impact of Heavy Duty.


19-year-old Casey Viator won the 1971 Mr. America after training HIT-style under Arthur Jones’ tutelage. Viator’s victory eclipsed the fact that a second 19-year-old, Mike Mentzer, was 10th in that same contest. The new Mr. A introduced his fellow teen to Jones. Soon after, Mentzer began consulting with HIT’s creator and revamping his training. When Mentzer won the 1976 Mr. America, he was celebrated as much for his philosophy as for his physique. He wrote articles for Muscle Builder/Power (the forerunner of FLEX), many of which covered specific techniques for intensifying workouts.

He advocated a heavier form of HIT. Whereas Jones prescribed one 20-rep set per exercise, Mentzer lowered the ideal rep range to six to nine: Choose a weight so heavy that you reach absolute failure at six to nine reps, then keep going. Failure wasn’t enough for Mentzer’s Heavy Duty system. It went beyond. The three techniques Heavy Duty prescribed most were forced reps, negative reps, and rest-pause. Mentzer trained with at least one partner (frequently his younger brother, Ray, 1979 Mr. America winner), who spotted him and assisted when he reached failure. The partner removed just enough stress for two or three forced reps. He helped raise the weight so it could be lowered as slowly as possible. Or he spotted while Mr. Heavy Duty paused between reps, grinding out a few “singles” in a manner known as rest-pause.

“If you’re skeptical [of Heavy Duty’s low volume], your subconscious child is telling you that more is better. In some cases that’s true. More money is better than less. But you can’t take that principle and blindly apply it to exercise and expect to get anything out of it.” — Mike Mentzer


As a 27-year-old IFBB Pro League rookie in 1979 noted especially for his delt, arm, and leg density, Mentzer was a phenomenon. Capping off the year by winning the heavyweight division of the

Mr. Olympia (but not the overall), he emerged as bodybuilding's heir apparent. He released two popular Heavy Duty booklets in 1980, and through his articles, seminars, and mail-order business his philosophy was as great a sensation as he was on stages. It seemed every bodybuilder tried his lower-rep HIT, though most eventually returned to a higher-volume system.

Then came the 1980 Mr. Olympia. The greatest representative of the old guard, Arnold Schwarzenegger, won. The insurgent 28-year-old Mentzer finished a controversial fifth and, in the aftermath, retired. He seldom even trained again. Mike Mentzer died in 2001 at 49. His Heavy Duty formed the cornerstone of six-time Mr. Olympia Dorian Yates' regimen, and it continues to influence bodybuilders today.


  • Go to full-rep failure in the six- to nine-rep range. Try to grow increasingly stronger in this range.
  • Always maintain proper form.
  • Push sets past failure with forced reps and negatives.
  • Rest-pause is another excellent method of transcending failure.
  • Divide your body parts into two workouts and allow 48 hours between workouts. For example, do workout A on Monday, B on Wednesday, A on Friday, B on Sunday (or Monday, if you prefer to take weekends off).


  • We have included Mentzer’s 1979 back workout. After he retired, Mentzer prescribed increasingly lower volume—eventually as few as only one or two all-out sets per body part every two weeks! The workout included here best represents an effective and practical Heavy Duty routine.
  • Train with at least one partner. Assist each other in going beyond failure.
  • Do your last warmup with approximately 75% of your working weight and stop before reaching failure.
  • Use pre-exhaust supersets. For example, in our back routine, pullovers (which isolate the lats) are done immediately before pulldowns (which work the lats with the biceps and rear delts).


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