How ‘muscle confusion’ can help your workouts

Here are a few questions to consider as you plan your 2020 exercise routines: Are your muscles confused? Should they be? And just how do we confuse our muscles, anyway?

These concerns are at the heart of a timely new study of what happens when we add variety to our gym workouts and, in the process, “confuse” our muscles. The study finds that shifting, quicksilver workouts can yield some benefits that more rote regimens do not, but the benefits may not be the ones that most of us would expect.

Anyone who pays attention to fitness trends has probably heard the term “muscle confusion.”

In essence, this theory claims that confused muscles, exposed to changing workouts, gain more size and strength than complacent muscles cycling through the same routines, even if people are lifting equivalent amounts of weight.

That idea has some appeal and many proponents, but little independent scientific backing.

So, for the new study, which was published in December in PLOS One and limited to a small group of healthy young men, a group of researchers from Spain and the United States decided to try to confuse a few muscles and see what would happen.

Overall, they found gains in muscular size and strength were almost exactly the same, whether they had maintained the same routines or often switched them up.

But those men completing the ever-changing workouts reported feeling much more motivated to exercise at the study’s end than the other group.

What these findings suggest is that muscles are not deterred or bored by unvarying routines, said Brad Schoenfeld, an associate professor of exercise science at Lehman College in New York and a co-author of the study. “They adapt to load,” he said, whether that load arrives through the same exercise or a different one each time.

But minds are not muscles and could be influenced by novelty, he said. “The differences in motivation scores at the end were substantial,” he said, suggesting that “from a purely motivational standpoint, variety matters.”

BRANDON THIBODEAUX/THE NEW YORK TIMES 2019 Shifting, quicksilver workouts, or “muscle confusion,” may yield mental benefits that more rote regimens do not.