Resistance Training and Respiratory and Immune‐Related Outcomes in Older Adults: A Randomized Controlled Trial

Age‐related declines in pulmonary function and immune regulation increase morbidity and mortality in older adults. Physical activity mitigates these effects, but the isolated impact of resistance training (RT) on lung function and immune responses remains unclear. Sixty‐nine older adults without participation for at least one year in structured exercise programs (aged 60–85 years) were recruited from a community extension program at a Brazilian university and randomized into an RT group ( n  = 31) or a control group ( n  = 38). This randomized controlled trial evaluated the effects of a 12‐week supervised RT program performed three times per week. Primary outcomes included spirometry parameters (FVC, FEV ₁ , FEV ₁ /FVC, PEF, and FEF ₂₅ – ₇₅ %), respiratory muscle strength (MIP and MEP), and inflammatory biomarkers (IL‐6, IL‐10, TNF‐α, and Klotho) in plasma and exhaled breath condensate. Secondary outcomes included handgrip strength, sit‐to‐stand performance, oxygen saturation, and body composition. Normally distributed outcomes were analyzed using repeated‐measures ANOVA, whereas non‐normally distributed longitudinal outcomes were analyzed using the Brunner–Langer approach for factorial longitudinal data. Between‐group differences in pre‐to‐post changes were additionally estimated using bootstrap 95% confidence intervals. No significant Group × Time interactions were observed for spirometric parameters. Significant Group × Time interactions were observed for MIP and MEP; however, significant pre‐to‐post changes were observed in the control group but not in the RT group. A significant Group × Time interaction was also observed for sit‐to‐stand performance, with improvement in the control group but not in the RT group. No significant Group × Time interactions were observed for handgrip strength or oxygen saturation. Significant Group × Time interactions were observed for plasma IL‐6, IL‐10, and Klotho (all p  < 0.001), as well as exhaled breath condensate IL‐6 ( p  = 0.006) and Klotho ( p  = 0.003). In contrast, no significant interactions were observed for plasma TNF‐α, exhaled breath condensate IL‐10, or exhaled breath condensate TNF‐α. Twelve weeks of supervised RT were associated with differential changes in respiratory muscle strength, functional capacity, and selected systemic and airway biomarkers in older adults. Significant Group × Time interactions were observed for MIP, MEP, the 1‐min sit‐to‐stand test, and selected inflammatory and aging‐related biomarkers, but not for pulmonary function. These findings indicate that the effects of RT varied across outcomes, rather than demonstrating consistent improvement across all assessed measures.

Trial Registration: ClinicalTrials.gov identifier: NCT06682221