Evaluating inflammatory outcomes: A systematic review and meta-analysis of aerobic versus resistance exercise interventions

Abstract

Chronic inflammation is widely recognized as a crucial contributor to the onset and progression of various diseases. Physical activity serves as a nonmedicinal intervention known to influence inflammatory dynamics. The specific effects of distinct exercise types, namely aerobic and resistance training, on inflammatory indices have not been fully delineated. This systematic review with meta-analysis seeks to clarify the relative impacts of these 2 forms of exercise on markers of inflammation. An exhaustive literature review was performed across several databases, including MEDLINE, EMBASE, and the Cochrane Library, to identify randomized controlled trials that assess the impact of aerobic versus resistance training on inflammatory markers. The primary variables of interest were alterations in inflammatory indicators such as C-reactive protein, interleukin-6, and tumor necrosis factor–alpha. We synthesized the data employing a random-effect meta-analytical approach and evaluated heterogeneity using the I² statistic. The literature search culminated in 36 randomized controlled trial with a collective participant count of 3616. Data analyses revealed that aerobic training is associated with a notable decrease in levels of interleukin-6 [standardized mean difference (SMD): −0.13, 95% CI: −0.31 to −0.05] and C-reactive protein (SMD: −0.28, 95% CI: −0.47 to −0.09), whereas resistance training is linked to a significant reduction in tumor necrosis factor–alpha levels (SMD: −0.61, 95% CI: −0.87 to −0.34). The investigation indicates that both aerobic and resistance training modalities play roles in diminishing inflammatory markers, likely through different biological processes. These insights highlight the critical nature of selecting appropriate exercise modalities to manage inflammatory health issues effectively. It is imperative to conduct further studies to unravel the precise mechanisms at play and to refine exercise recommendations for tailored management of inflammation.