Effects of Resistance Training Sets on Cognition and Brain-Derived Neurotrophic Factor in Cognitively Impaired Individuals: A Quasi-Experimental Study.

BACKGROUND: The minimum effective resistance training (RT) volume prescription strategy for individuals with cognitive impairment (CI) remains unclear in the literature. This study compared the effects of single-set (SET1) versus three-set (SET3) RT on global cognition, brain-derived neurotrophic factor (BDNF), and physical performance in individuals with CI. METHODS: The study was formally registered on ClinicalTrials.gov (NCT06185010; V2) and followed the TREND guidelines. We randomized thirty participants to SET1 (n = 15) or SET3 (n = 15) and nonrandomly allocated thirteen participants to a control group (CON). The 8-week RT program included leg press (40-60% one-repetition maximum [1RM]), chest press (50-70% 1RM), chair squats, and med ball throws. Primary outcomes assessed at baseline and post-intervention included the Dementia Rating Scale-2 (DRS-2), serum BDNF, and the Short Physical Performance Battery (SPPB). Secondary outcomes were creatine kinase (CK) and composite strength (handgrip strength plus 1RM leg and chest press). We analyzed the outcomes using generalized linear mixed models. RESULTS: There were no post-intervention between-group differences for DRS-2 or BDNF, and neither group demonstrated increases from baseline. Physical performance improved in both RT groups compared with CON, with SPPB increasing by 2.7 points in SET1 and 1.4 points in SET3. CK did not change meaningfully. Composite strength did not differ between groups at post-test; however, only SET1 showed a significant increase (+12 kg). CONCLUSION: Both sets improved physical performance but were not associated with detectable changes in cognition or BDNF in individuals with CI. Single-sets may represent an efficient strategy in this population.