Short-term high-intensity resistance training: a feasibility study on pulmonary, immune and physical-functional fitness benefits for older adults with metabolic syndrome

The incidence of metabolic syndrome (MetS) is rising rapidly, particularly among older adults, and is associated with comorbidities that impair respiratory and immune functions. Physical exercise has proven effective in mitigating the adverse effects of both aging and MetS. However, evidence on the impact of high-intensity resistance training (HIRT) on the respiratory and immune systems in older adults with MetS remains limited. This study aimed to evaluate the effects of HIRT on respiratory function, skeletal muscle strength, and immune modulation in older adults with MetS, highlighting its potential as a complementary therapeutic approach. A total of 43 older adults with MetS were enrolled and divided into two groups: a HIRT intervention group (n = 23; mean age 66.71 ± 4.98 years) and a non-exercising control group (n = 20; mean age 66.91 ± 5.26 years). The HIRT protocol involved twice-weekly sessions (10 total) over 5 weeks, performed at 80-90% of one-repetition maximum. Results showed that HIRT significantly improved lung mechanics (R5Hz, R20Hz, Z5Hz, X5Hz), peripheral muscle strength, and both maximal expiratory and inspiratory pressures. Furthermore, HIRT increased anti-inflammatory and anti-fibrotic cytokines in sputum (klotho, IL-10, adiponectin) and serum (klotho, relaxin-1, relaxin-3, IL-10), while reducing pro-inflammatory cytokines in sputum (IL-6, TNF-α) and serum (IL-1ra, IL-6, TNF-α, leptin). A decrease in total leukocyte, neutrophil, lymphocyte, and monocyte counts was also observed. In conclusion, HIRT effectively mitigates the effects of MetS on respiratory, muscular, and immune functions in older adults and may be recommended as a complementary strategy for managing MetS in this population.