EXERCISE AND INTERMITTENT FASTING AS PREVENTIVE MEASURES OF EARLY AGING THROUGH SIRT1: A NARRATIVE REVIEW

Obesity accelerates biological aging, which showed in the low level of sirtuin 1 (SIRT1), an NAD⁺-dependent deacetylase that regulate inflammation, mitochondrial function, cellular senescence, and oxidative stress. This narrative review examined how aerobic exercise at different intensities and intermittent fasting (IF), especially time-restricted feeding (TRF), affect SIRT1 as a marker of early aging, and what is known about their combination. Human and animal studies reporting SIRT1 after exercise, fasting, or both were summarized narratively, and exercise intensity was classified with standard heart rate and oxygen-uptake cut-offs. Moderate-intensity aerobic exercise raised circulating or tissue SIRT1 in people and rodents with obesity, and high intensity did not clearly add to this. Fasting results were mixed: short-term TRF and Ramadan fasting raised SIRT1 expression in some human studies, whereas an 8-hour fast in healthy men did not, and Ramadan fasting in adults with overweight tended to lower it. Alternate-day fasting generally preserved SIRT1 in rodent brain. Combined fasting and exercise gave additive fat-mass reductions in randomized trials, but an additive effect on SIRT1 appeared in one rat study and not in a mouse study that tested the interaction. Human trials that combine TRF with aerobic exercise and measure serum SIRT1 alongside direct aging endpoints are needed.