Influence of Proximity to Failure, Relative Intensity, and Volume on Voluntary Performance and Fatigue Symptoms After Resistance Training: A Systematic Review.

Abstract: Varela-Olalla, D, del Campo-Vecino, J, and Balsalobre-Fernández, C. Influence of proximity to failure, relative intensity, and volume on voluntary performance and fatigue symptoms after resistance training: a systematic review. J Strength Cond Res XX(X): 000-000, 2025-Fatigue management is of paramount importance and holistic approaches that include neuromuscular and perceptual factors have been developed in recent years because knowledge of the sites of the neuromuscular system that can be altered, and its perceptual impact, is mandatory for programing adequate stimulus-fatigue ratios. Most of the information in this regard comes from continuous whole-body exercise and isometric training, with less information regarding holistic fatigue analysis during traditional resistance training (RT). This review aims to analyze the influence of RT variables on voluntary performance, neuromuscular and perceived fatigue variables. Search was performed on PubMed and Web of Science following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, using terms related to resistance training and fatigue. Records were included if they provide comparisons between RT protocols in terms of acute fatigue in healthy humans. Results from fifty-one articles were included which indicate that contractile function, afferent feedback and perceptual responses are more affected during RT than muscle activation parameters being set duration, proximity to failure and total volume the main determinants of the impairments. Higher fatigue is induced as sets approach failure with high training volumes and densities, especially for protocols using light loads.