But what about that other great organ: the brain? Does it respond as effectively to a good workout?
Lisa Schoonerman believes it can.
She and her partner started a "brain gym" in San Francisco -- called vibrantBrains -- dedicated to that idea.
Schoonerman's mother was diagnosed with front temporal dementia. Earlier, Jan Zivic, her vibrantBrains co-founder, suffered head trauma in a car wreck.
Schoonerman said these factors prompted her to do research into brain health. "I think everyone knows how to avoid heart disease. I wondered if something could be done with cognitive function. If exercise makes the heart healthier, is there anything similar for the brain?"
At Schoonerman's brain gym in San Francisco, people can use several software programs designed to give their brains a workout.
But another key component of her program, she said, is the socializing that goes on at the center.
Schoonerman said people could use the licensed computer programs alone at home. "But it's clear that when you are trying to start a new, good habit, like exercising, you benefit more from practicing with like-minded people. The social interaction is important to brain health.
"I want a gym for brain exercise to be part of everyone's healthy life."
In California, Schoonerman said her partner was a "super high functioning" person when she had a wreck and suffered a head injury. "It was a life-changing experience, and it reinforces the appreciation we should have of something we often take for granted."
