DEAR DOCTOR: I've been reading that high-intensity interval training can slow down the aging process. I'm not too keen on this approach, but I do walk at least a mile every day.
DEAR READER: Our bodies change as we age. Cardiovascular capacity decreases, muscle mass is lost and body fat increases. Decades of studies show that regular exercise can prevent and even reverse these trends. Staying active boosts the immune system, improves muscle tone and balance, enhances cognitive function, improves the quality of sleep and has a positive effect on mood.
Now, a new study published in the journal Cell Metabolism adds a bit of a twist. While any amount of exercise beats sitting on the couch, a specific kind, known as high-intensity interval training, or HIIT, appears to change the body at a cellular level. Specifically, this type of exercise affects the mitochondria, which are structures within cells that make energy available to the body.
So what is high-intensity interval training? It's a brief workout performed several times per week. HIIT alternates bursts of intense exercise, during which muscles use more oxygen than the body has available, known as anaerobic exercise, with periods of slower activity in which the oxygen debt is repaid.
In basic terms, HIIT goes roughly like this:
Does HIIT slow the aging process? That depends on what you mean by aging. Yes, this study shows that in terms of mitochondrial efficiency, the clock can be turned back. But whether this translates into longevity remains to be seen. Still, in terms of potential health benefits, finding a way to make peace with your aversion to high-intensity interval training could be a worthwhile goal.
Elizabeth Ko, M.D., is an internist and primary care physician at UCLA Health.
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