Her newest proposal to the NIH seeks to get to the bottom of how exercise – or lack of it — affects the aging body. The project involves more than 93,000 women with a mean age of 78, and harkens back to Stefanick’s doctoral, postdoctoral and research associate days at Stanford. Back then, she conducted human exercise studies with Peter Wood, her marathon partner and Stanford mentor who helped her see a path beyond her abhorrence of animal research, which had nearly caused her to drop out of graduate school.
Stefanick believes the new research will be “the best study of aging women that exists.” In particular, she expects it to bear out the benefits of exercise.
“I personally think the most important intervention for reducing morbidity and mortality and maintaining physical and cognitive function is physical activity,” she said.
Research already links exercise to positive effects on blood pressure, heart rate and cholesterol numbers. So what’s the need for a new study?
“All the data support that belief – but science requires a higher level of evidence,” Stefanick said. “Actual proof is needed to show that increased activity and decreased sedentary behavior lead to improved aging.”
“Women who exercise on their own may by physiologically different from women who don’t exercise, so we don’t know that their exercise caused the improved health they experience. The question we hope to answer is – do we really need to promote exercise in the population? Does exercise truly benefit the most older women?” Stefanick said.
To bolster a case for medically recommending physical activity, she said, “We need a large trial that randomly assigns women to exercise or control groups that we can study.”
Participants will be assigned specific daily exercise routines – mostly walking, strength training, balance and flexibility. Stefanick and her team will determine actual health outcomes, particularly heart disease and stroke, but also cancer, osteoporotic fractures, and quality of life. A sedentary group will provide comparison.
Stefanick firmly expects exercise to prove itself.
“If we’re successful, if we prove physical activity works, people will say, duh, we already knew that, but the reality is we don’t know it, and that’s the issue,” she said.