“Never skip leg day” sounds like something a swole gym bro with killer quads might harp on about. But doctors also sing the praises of lunges and split bench squats, and not for the reason you might think.
In a recent article for Vogue, California-based physician Dr. Chris Renna said: “Stronger leg muscles are linked to better cognitive function in aging mainly through their effects on blood flow, metabolic health, brain structure, and physical/social activity patterns.”
Muscle mass starts to decline at age 30. As the largest muscle group in the body, maintaining muscle strength in the thighs and glutes is especially important for healthy aging—and apparently, brain function.
Multiple studies back this up. A 2015 study of over 300 female twins, ages 43 to 73, found the more powerful their legs (measured by pushing one foot as hard and fast as possible against a pedal), the better their cognition a decade on (measured by a series of tests on memory and processing speed).
Another study of 1,500 older adults, with an average age of 70, conducted in 2018, also found an association between stronger legs and better performance on tests of their cognitive function.
A separate study also in 2018, this time conducted on mice, found exercising the lower extremities to be critical to brain and nervous system health. Researchers discovered that neurological health depends as much on signals sent from the leg muscles to the brain as it does the other way around.
This offers an explanation for why patients with neurological diseases experience rapid decline once their movement becomes limited.
“It is no accident that we are meant to be active: to walk, run, crouch to sit, and use our leg muscles to lift things,” the study’s author, Dr. Raffaella Adami, told academic journals publisher Frontiers. “Neurological health is not a one-way street with the brain telling the muscles ‘lift,’ ‘walk,’ and so on.”
The brain-leg connection can be explained by tiny proteins called myokines. When the leg muscles are exercised, they release these messenger molecules, which reach the brain via the bloodstream. Here, they support learning ability, memory, and neural adaptation, the process by which the nervous system adjusts and improves its functioning.
A simple leg day session that includes weight-bearing exercises like lunges, squats, and calf raises will not only improve physical strength. By increasing blood flow, the brain floods with extra oxygen, helping to decrease harmful inflammation in the body.
If you’ve been known to skip squats or lunges at the gym, it doesn’t help that modern life is, for many, characterized by a concerning lack of movement. Commuting to work to sit at a desk for hours, before commuting home again to sit some more on the couch, means our legs often aren’t getting the regular exercise they need to keep our brain working optimally.
So drop some squats in front of some Netflix or while listening to a podcast. Your glutes won’t be the only part of your body that thanks you.