While we battle it out every day in the gym and pay with our sweat and tears to build muscle, a new study suggests that over the course of evolution, the human body actually eschewed muscle growth to fuel brain development.

“For a long time we were confused by metabolic changes in human muscle, until we realized that what other primates have in common, in contrast to humans, is their enormous muscle strength,” said Dr. Kasia Bozek, the first author of the study, which is called Exceptional Evolutionary Divergence of Human Muscle and Brain Metabolomes Parallels Human Cognitive and Physical Uniqueness.

Our nearest animal relative is the chimpanzee, and the research claims the essential molecules in human muscle have changed 10 times more than cousin chimp over evolution, while the metabolome (dictionary definition: “the full complement of metabolites present in a cell, tissue, or organism in a particular physiological or developmental state”) in the human brain changed four times faster.

“Our results suggest a special energy management in humans that allows us to spare energy for our extraordinary cognitive powers at a cost of weak muscle,” said Bozek. To rule out the lazy-humans-who-eat-crap-and-don’t-move-factor, researchers took active outdoor macaque monkeys and brought them into confined spaces and fed them foods filled with fat and sugar (they turned them into slobs), but the significant change in setting and lifestyle had a minimal impact on the metabolome of the monkeys tested.

Yep, it would appear that we expanded a lot of our energy on the development of our brains over time and our muscle growth paid the bill. It’s a bit on a conundrum for the M&Fer, who is supremely motivated to build muscle, but if we had not gone down this evolutionary path, then we might have missed out on, well, civilization as we know it. So deal with it. Or, if you feel that you want to redress the strength gap between humans and chimpanzees (the research also showed they chimps can lift over double what humans can) then we suggest you head to our workouts section and get busy!