Who was Mike Mentzer? Mike Mentzer was a legendary bodybuilder who won the 1978 Mr. Universe, becoming the first bodybuilder ever to get a perfect score from the judges. Considering the lack of science-based knowledge, supplements and the variety of elaborate training techniques we have today, that win was a huge accomplishment that launched Mike’s future career. During the next two decades, Mike Mentzer created a lot of fuss with the unconventional training philosophy he wrote about in his Heavy Duty articles and which emphasized brief, intensive and infrequent workouts. His popularity waned after the infamous Mr. Olympia contest in 1980, when he lost the title to Arnold Schwarzenegger and had the crowds shout “Fix!” at him.
Mentzer believed that almost all bodybuilders were overtraining and that this slowed down their progress. At that time, most top-level bodybuilders had long training sessions that included more than 20 sets per body part, 5-6 days a week, and Mike thought they were doing it completely wrong. He himself typically trained three times a week and his 30-minute workouts incorporated no more than 5 sets per body part. Mentzer preached high-intensity exercise once every five to seven days and stressed that 20-30 minutes were ideal for achieving maximum muscle stimulation. But as his shape and health deteriorated throughout the 90’s, Mike lost a big part of his followers. To this very day, different bodybuilders hold radically different views on his approach – while some truly believe he was a genius, others think he was completely crazy.
However, some new scientific studies proved that there is some truth in Mentzer’s claims. One team of researchers tried to examine how muscle mass and strength were influenced by reducing the number of training sessions per week to one. For this purpose, 70 healthy adults were divided into two groups according to their age. The first group consisted of young adults between ages 20 and 35, while the other consisted of older adults, aged 60-75. During the first phase of the study, which lasted 16 weeks, both groups performed three sets of three resistance-training exercises three times a week. Then, they were divided into three groups for the second, de-training phase: one group completely stopped training, the second group reduced the training days from three to one but kept the same number of sets, and the third group also reduced the training days from three to one but reduced the training sets from three to one as well.
The results from this elaborate study showed that when it comes to Mentzer’s training method, age makes a big difference. In other words, in the group of older adults, nobody maintained their muscle size after cutting down to one session per week, even though they managed to maintain their strength. On the other hand, the younger bodybuilders who reduced both the number of sessions per week (from 3 to 1) and the exercise volume (from 3 sets to 1) maintained their muscle size, while those who cut down to exercising once a week but maintained the exercise volume (3 sets) managed to increase their muscle size. The researchers concluded that once-a-week training with an adequate exercise volume can successfully stimulate muscle growth in younger adults, but older gym goers who want to maintain their muscle mass should stick to longer and more frequent training sessions.