We all know exercise is good for us. But how does it really work inside our bodies?
That’s the question behind a $2.3 million grant recently awarded to two UC Davis researchers who will study how intense bouts of exercise change the minute, molecular structures inside tissue, muscle and organs. It’s part of a nationwide, six-year study by researchers at more than 20 universities and health research centers, funded by the National Institutes of Health.
“This will be the first project that really tries to understand at a fundamental level how exercise does what it does. Not just on the heart and brain, but on all organ systems,” said professor Sue Bodine, a physiologist in the UC Davis physiology and membrane biology department.
Her partner on the six-year project is fellow UC Davis physiology professor Keith Baar.
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They’ll be working with more than 1,500 rats over six years, putting them through the human equivalent of endurance exercise, such as treadmill running, for eight to 12 weeks. Later, the rats will be euthanized so researchers can dissect and analyze their muscles, tissues, blood and organs to gauge the effects of exercise.
Similar assessments – minus the organ dissections – will take place on 3,000 human volunteers, ranging in age from 12 through adulthood, at clinical sites nationwide, including UC Irvine. The 2,700 adult volunteers will be a mix of sedentary and active participants, given exercise regimens for 12 weeks, such as lifting weights and running 30 minutes on a treadmill. Afterward, their blood, muscle and adipose tissue will be analyzed. About 300 sedentary children, selected by UC Irvine, will be monitored on treadmills, cycles and elliptical machines, with follow-up blood testing.
Researchers will look for changes in proteins or genes that may show how exercise benefits our internal organs, Bodine said. For example, when muscles contract to produce movement, researchers will check to see if certain proteins are released into the bloodstream and transported to organs.
It’s not news that regular physical activity offers multiple health benefits, including less risk of dying from heart disease or developing diabetes and high blood pressure. But only 20 percent of adults 18 and older get the recommended amount of weekly aerobic and muscle-strengthening activities, according to a 2015 study by the National Center for Health Statistics. (The 2008 federal guidelines recommend adults get at least 150 minutes a week of “moderate-intensity” aerobic activity, plus at least two days a week of muscle-strength activities.)
Calling the high levels of overeating and physical inactivity among Americans “alarming,” Bodine said the $170 million nationwide study could eventually help doctors prescribe specific types of exercise, both to help people stay healthy and to prevent or treat diseases, such as diabetes or Alzheimer’s.