Effects of low-intensity aerobic and resistance training on physical function, adiponectin, and metabolic health in oldest-old women: a randomized controlled trial

Abstract Background Few studies have examined exercise interventions in oldest-old women—that is, women aged 85 years and older—despite their high risk of experiencing functional decline and metabolic dysregulation. Thus, the present study investigated the effects of low-intensity aerobic and resistance training on functional fitness and selected metabolic biomarkers in this population. Methods This randomized controlled trial included women aged 85 years and older who were assigned to a control group (CG), an aerobic exercise group (AEG), or a resistance exercise group (REG). Both exercise groups completed 24 weeks of low-intensity training. Functional outcomes included handgrip strength, 30-s chair stand, 30-s arm curl, and 2-min step performance. Biological outcomes included adiponectin, high-sensitivity C-reactive protein (hs-CRP), fasting insulin, homeostatic model assessment for insulin resistance (HOMA-IR), and glucose. Intervention effects were evaluated using mixed-effects repeated-measures analyses including group, time, and group × time interaction. Results Handgrip strength showed a significant group × time interaction, with a significant increase observed only in REG. Both exercise groups showed significant improvements in 30-s chair-stand, 30-s arm curl, and 2-min step performance relative to CG. Adiponectin increased significantly in both exercise groups, with the largest increase in REG. Fasting insulin and glucose were significantly lower in AEG and REG than in CG at 24 weeks, whereas hs-CRP and HOMA-IR did not show significant intervention effects. Conclusion Low-intensity aerobic and resistance training was found to improve multiple domains of functional fitness in oldest-old women. Favorable changes were also observed in selected metabolic biomarkers, including adiponectin, fasting insulin, and glucose. These functional and biomarker outcomes should be interpreted as parallel responses to the intervention rather than evidence of a direct relationship between functional improvements and biomarker changes. Low-intensity exercise may represent a feasible strategy for supporting functional capacity in women of very advanced age.