An Exploratory Study of the Short-Term Association of Resistance Training With Circulating Inflammatory Biomarkers, Plasma Brain-Derived Neurotrophic Factor, and Cognitive Function in Healthy Midlife Adults.

Plasma IL-6 decreased significantly after 4 weeks of resistance training in the full analytic cohort.

• IL-6 decreased from 2.83 ± 1.60 to 2.09 ± 1.34 pg/mL, a mean change of -0.74 pg/mL.
• The paired comparison was statistically significant.
• Assessments were completed at baseline and 72 hours after the final training session.
• Full-cohort analysis included 500 healthy adults aged 50-65 years.

Plasma TNF-α decreased significantly after 4 weeks of resistance training in the full analytic cohort.

• TNF-α decreased from 3.61 ± 1.07 to 3.12 ± 0.96 pg/mL, a mean change of -0.49 pg/mL.
• The paired comparison was statistically significant.
• The study was a single-arm interventional pre-post design with no control group.
• Training was conducted three times weekly for 4 weeks.

Plasma BDNF increased significantly after 4 weeks of resistance training in the full analytic cohort.

• BDNF increased from 23.4 ± 5.6 to 26.1 ± 6.2 ng/mL, a mean change of +2.7 ng/mL.
• The paired comparison was statistically significant.
• The study measured plasma rather than central (cerebrospinal fluid) BDNF, which is noted as a limitation.
• Participants were healthy adults aged 50-65 years.

Working memory performance as measured by the two-back task improved after 4 weeks of resistance training.

• Two-back accuracy increased from 83.7 ± 8.9% to 87.6 ± 7.2%.
• Two-back reaction time decreased from 690 ± 89 ms to 652 ± 82 ms.
• These changes were part of the primary full-cohort outcomes.
• Assessments were completed 72 hours after the final training session.

Inhibitory control performance as measured by the Stroop task improved after 4 weeks of resistance training.

• Stroop accuracy increased from 89.8 ± 7.4% to 91.9 ± 6.2%.
• Stroop interference decreased from 238 ± 47 ms to 211 ± 41 ms.
• These were primary full-cohort outcomes alongside the biomarker measures.
• The Stroop task assessed inhibitory control, one component of executive function.

Adherence-stratified analyses showed larger numerical biomarker and cognitive changes among participants completing 11 or more sessions.

• Adherence categories were: ≥11 sessions (n = 312), 10 sessions (n = 146), and <10 sessions (n = 42).
• The maximum possible sessions over 4 weeks at 3 sessions/week was 12.
• These subgroup findings were interpreted descriptively because adherence groups were not randomized.
• Secondary adherence-stratified analyses were pre-specified as secondary rather than primary analyses.

The study enrolled 500 healthy midlife adults after screening 647 individuals, with a single-arm pre-post design.

• 647 individuals were screened and 500 healthy adults aged 50-65 years entered the supervised resistance-training program.
• Training was supervised and conducted three times weekly for 4 weeks.
• The study had no control or comparator group, making it a single-arm interventional pre-post design.
• Full-cohort analyses were treated as primary analyses, while per-protocol, adherence-stratified, and sensitivity analyses were reported as secondary analyses.

The authors identified key limitations including the single-arm design, absence of central biomarkers, and short follow-up duration.

• The single-arm design precludes causal inference or comparative efficacy conclusions.
• Only plasma BDNF was measured; central biomarkers such as cerebrospinal fluid BDNF were not assessed.
• Follow-up was limited to 72 hours after the final session at the end of 4 weeks.
• The findings 'reflect within-cohort pre-post associations rather than comparative efficacy and should be interpreted cautiously.'