Age and mating status modulate combined efficacy of α-lipoic acid and climbing to mitigate high-fat diet-induced oxidative stress in Drosophila melanogaster

High-fat diet (HFD) intake is a potent inducer of oxidative stress, promoting metabolic dysfunction and accelerated ageing. Identifying interventions capable of mitigating this persistent redox burden is therefore essential. This study investigated the combined efficacy of α-lipoic acid (LA) supplementation and a daily climbing regimen in counteracting HFD-induced oxidative stress across different life stages and mating statuses in Drosophila melanogaster . Flies were maintained on an HFD and subjected to LA (2 mM or 2.5 mM), climbing exercise, or their combination during early, mid, or late life. Oxidative stress resistance was evaluated using hydrogen peroxide challenge assays, and peroxide accumulation was quantified via the FOX method. Combined LA and climbing treatment significantly enhanced stress resistance and reduced peroxide levels in early- and mid-life flies, outperforming either intervention alone. This benefit was most pronounced in unmated flies, indicating that physiological costs associated with mating diminish adaptive responsiveness. Notably, while LA alone reduced fecundity, its combination with climbing restored reproductive output, suggesting exercise-mediated alleviation of resource-allocation trade-offs. In late-life groups, the interventions produced only modest biochemical improvements without corresponding lifespan extension, highlighting age-related loss of physiological plasticity and the limited reversibility of cumulative oxidative damage. Overall, the findings demonstrated that integrating antioxidant supplementation with hormetic exercise elicited superior protection against HFD-induced oxidative stress, but the magnitude of benefit depended strongly on age and reproductive status. These results underscore the importance of early, multifaceted interventions to maintain redox balance and physiological resilience. • HFD induced significant oxidative stress and reduced stress resistance across life stages in D. melanogaster . • LA and climbing individually offered partial protection, but together enhanced oxidative stress resistance. • Combined treatment reduced peroxide levels and improved lifespan in early- and mid-life flies, especially in unmated group. • LA reduced fecundity, but together with climbing restored fecundity, implying exercise-mediated reduction of physiological trade-offs. • Late-life flies had limited response, implying age-dependent loss of physiological plasticity and importance of early intervention.