Connie Capone | August 19, 2020

Exercise is hard work, but it pays. Adding to the many reasons to get moving is compelling new research that has found that two exercise methods can slow the aging process by preventing cellular aging: high-intensity interval training (HIIT) and endurance training.

What are these exercise methods, and why do they work?

The anti-aging response

In a study published in the European Heart Journal, researchers examined the cellular effects of different exercise interventions. Over 6 months, 124 participants were instructed to perform one of three modalities: endurance training, HIIT, or resistance training (using free weights, weight machines, resistance bands, or bodyweight exercises to increase muscular strength). Some participants were assigned to a control group and instructed to make no change to their exercise regimen.

After 6 months, researchers found that HIIT and endurance training, but not resistance training, increased telomerase activity, which is beneficial for cell growth and replication. Telomeres are nucleotide sequences found at the end of chromosomes that protect our genetic information. When they shorten, cellular aging occurs. HIIT and endurance training were found to increase telomere length, inhibiting cell death, and ultimately producing an anti-aging effect.
Similar results were reported in Cell Metabolism, in a study that compared the metabolic responses from HIIT and resistance training. Participants were placed in cohorts by age (<30 and >65), and randomized to one of three exercise routines: HIIT, resistance training, or a combination of both. After 12 weeks, all exercise routines resulted in improved fitness, boosted insulin sensitivity, and increased lean mass, but HIIT training increased aerobic capacity and mitochondrial function, leading to a reduction in mitochondrial decay, which contributes to aging.

For older adults, HIIT training yielded the most significant reversal in cellular aging. Participants over 65 saw a 69% increase in mitochondrial respiration—the metabolic process within mitochondria that converts energy into adenosine triphosphate (ATP), the universal energy donor in our cells. Additionally, adults under 30 saw a 49% increase. Resistance training did not provide this effect in either age group.

According to senior author Sreekumaran Nair, MD, PhD, “Any exercise is better than being sedentary.” Still, he noted that for older adults, HIIT is a highly efficient way to counteract many age-related changes.

Best part? HIIT training has also been proven to be the best exercise method to reduce body fat.