This article was originally published on March 30, 2017.
Ask any middle-aged person who look years younger than their biological age what their secret is, and they’re likely to mention that they frequently exercise (and eat well!). Indeed, research has confirmed that regular, moderate exercise fights aging on multiple levels, including the cellular, muscular, and genetic levels. The benefits of regular exercise range from boosting the elasticity of the dermis to increasing telomere length (i.e. protecting our DNA).
While all regular exercise of any sort (provided it doesn’t cause frequent injury) can play a role in slowing down the clock, a recent report from the Mayo Clinic indicates that low-impact high-intensity interval training (HIIT) is likely the most effective style of exercise when it comes to reversing the aging process of muscles at the cellular level.
Researchers monitored a group of individuals with varying ages (between 18 and 30 and 65 and 80) for a period of about three months. Randomized groups practiced a variety of different exercise styles, including HIIT, resistance training, and cross-training. The research team took muscles biopsies before and after the three-month period to measure how the various exercises affected cells. While all types of workouts improved lean body mass and insulin resistance, HIIT stood out for its ability to reverse certain cellular aspects of aging.
Specifically, “interval training boosted the ability of the mitochondria within cells to generate energy by 69 percent in older volunteers, and by 49 percent in the younger group,” New Scientist reports. Ultimately, improved mitochondrial functionality results in increased muscle protein, improved energetic functions, and enlargement of muscles.
Mitochondrial functioning plays a key role in maintaining health—when it naturally declines as we age, muscles may no longer burn blood sugar as effectively as they did when we were younger, putting the body at risk for diabetes and other complications. Fortunately, by reversing this process through HIIT, older individuals can once again experience more efficient, “youthful” mitochondrial functioning:
“After three months of interval training, everything converged towards what we saw in young people,” says Sreekumaran Nair, head of the research team.
As we understand things so far, HIIT operates through the calcium-calmodulin kinase (CaMK) path and the adenosine monophosphate kinase (AMPK) path. Together, these pathways activate PGC-1alpha, which supports the development of skeletal muscle functions. In the plainest of terms, HIIT “hits” two paths in the body that prompt healthy muscle function and growth.
To maximize results, researchers suggest combining HIIT with resistance training. It’s also important to note that any exerciser (of any age) may benefit from prioritizing low-impact high-intensity cardio to reduce the risk of stress fractures, muscle tears, and exertional rhabdomyolysis (a rare condition associated with poorly structured CrossFit training). Bicycling, elliptical training, or water running are low-impact exercises that can be performed at a range of intensities.
Have you tried HIIT workouts?
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