Peak muscle mass occurs, on average, sometime during your early 40s. After this, your muscle mass will begin to gradually decline, eventually leading to changes in your mobility, strength and ability to live independently.

“Without question, exercise is the most powerful intervention to address muscle loss, whether it occurs in the context of advancing age or debilitating chronic or acute diseases,” said Nathan K. LeBrasseur, Ph.D., a researcher in molecular aspects of endurance and exercise at Mayo Clinic in Rochester, Minnesota.

High-Intensity Interval Training Works Best for Aging Muscles

In a study by Mayo Clinic researchers, three types of exercise were pitted against each other, and a non-exercising control group, to determine if different types of exercise work better than others to protect aging muscles. A clear winner was revealed.

The study involved 72 sedentary people aged either 30 or younger or 64 and over. They engaged in 12 weeks of high-intensity interval training (HIIT) on stationary bikes, vigorous resistance training or a combination of exercises (moderate pace stationary bike combined with light weight lifting).

Among the younger exercisers, the HIIT group had changes in 274 genes, compared to 170 genes for the moderate combination exercisers and 74 among the resistance group. The changes among the older exercisers were even more striking. As The New York Times reported:

”Among the older cohort, almost 400 genes were working differently now, compared with 33 for the weight lifters and only 19 for the moderate exercisers.”

Many of these affected genes, especially in the cells of the interval trainers, are believed to influence the ability of mitochondria to produce energy for muscle cells.

When you exercise, your body will respond by creating more mitochondria to keep up with the heightened energy requirements. Aging is inevitable, but your biological age can be quite different from your chronological age, and your mitochondria have a lot to do with your biological aging.

“Supervised HIIT appears to be an effective recommendation to improve cardio-metabolic health parameters in aging adults,” the researchers concluded. As The New York Times noted:

”It seems as if the decline in the cellular health of muscles associated with aging was ‘corrected’ with exercise, especially if it was intense, says Dr. Sreekumaran Nair, a professor of medicine and an endocrinologist at the Mayo Clinic and the study’s senior author.”

At least two additional studies, one in the Journal of Applied Physiology and the other in Neuroscience also showed that exercise induces mitochondrial biogenesis in the brain, with potential benefits such as reduction or reversal of age-associated declines in cognitive function and helping to repair brain damage following a stroke, respectively.

Mitochondrial damage can also trigger genetic mutations that can contribute to cancer, so optimizing the health of your mitochondria is a key component of cancer prevention.

Decreased Insulin Resistance

A recent study found that HIIT positively impacted insulin sensitivity. The study involved people with type 2 diabetes, and just one session improved blood sugar regulation for the next 24 hours:

“Positive changes have been observed in insulin resistance in as little as [eight] minutes per week when executed at an intensity more than 100 [percent].”

Is HIIT Safe for Seniors?

HIIT may seem too intense for the elderly, but rest assured you can perform HIIT at any age and still reap major benefits. The only difference is that the older you are the lower your maximum heart rate will be, and the more gradually you will want to increase your repetitions.

At Wellspring, we have ShockWave classes, “Dubbed the most efficient total-body workout in the world. ShockWave is extreme cross-training at its best. This is HIIT at its finest.”