A study by Mayo Clinic has suggested that high-intensity interval training (HIIT) can reverse signs of ageing at the cellular level.

The research, published in the Cell Metabolism journal, studied 72 sedentary adults divided into two age groups of "young" (18 to 30 years old) and "older" (65 to 80 years old).

Each individual was then assigned one of three 12-week workout routines – HIIT cycling, strength training or a regime combining the two.

All training types improved lean body mass and insulin sensitivity, but only HIIT and combined training improved aerobic capacity and mitochondrial function for skeletal muscle. A decline in mitochondrial content and function are common in older adults.

HIIT also improved muscle protein content that not only enhanced energetic functions but also caused muscle enlargement, especially in older adults.

The researchers concluded that HIIT significantly enhances the cellular machinery responsible for making new proteins. That, in turn, contributes to protein synthesis which can reverse the adverse effects of ageing. Adding resistance training, however, is important to achieve significant muscle strength.

“We encourage everyone to exercise regularly, but the take-home message for ageing adults that supervised HIIT is probably best, because, both metabolically and at the molecular level, it confers the most benefits,” said K. Sreekumaran Nair, a Mayo Clinic endocrinologist and senior researcher on the study.

"HIIT reversed some manifestations of ageing in the body’s protein function – but increasing muscle strength requires resistance training a couple of days a week."