Effects of resistance training on running economy: a systematic review and meta-analysis

Introduction: Running economy (RE) is a determining factor in the performance of long-distance runners, influencing energy efficiency and expenditure. Endurance training has been proposed as a strategy to improve RE, although its effectiveness is still debated. Objective: To systematically and meta-analytically review studies that evaluated the effects of endurance training on RE in long-distance runners (≥10 km). Methodology: A systematic search was conducted in PubMed, Web of Science, and Scopus, with no date restrictions, until March 2024. Manuscripts that met the inclusion criteria were analyzed. Results: Of 895 studies found, 8 were included. Risk of bias was assessed, and inverse variance-weighted standardized mean differences (SMDs) were calculated to estimate the overall effect of endurance training on RE, with 95% CI. A total of 80 subjects were analyzed (age: 36.2 ± 6 years; VO₂max: 49.2 ± 4 ml·kg⁻¹·min⁻¹). The average training intensity was 83% of 1RM (±7.5%). Endurance training significantly improved RE (p = 0.003, d = 0.47). Intensity, protocol duration, and running specialty positively influenced the results. Discussion: The findings support that endurance training improves RE in long-distance runners. Conclusions: Training structure influences outcomes, and further studies are required to further investigate its effects.