Is failure necessary for muscle growth? An updated review of resistance training to concentric failure

Muscle hypertrophy — the increase in skeletal muscle fiber cross-sectional area — is a central goal of resistance training (RT) programs for athletic performance, aesthetics, and health. Among the variables that can be manipulated in RT, performing sets to concentric failure, the point at which a repetition cannot be completed through its full range of motion despite maximal voluntary effort, remains one of the most debated. This narrative review synthesizes current evidence on the physiological basis, comparative effectiveness, and risks of training to concentric failure for muscle hypertrophy, incorporating findings published through 2026. Mechanistically, proximity to failure is theorized to increase recruitment of high-threshold motor units and metabolic stress, both implicated in hypertrophic signaling. However, when total training volume is equated between conditions, recent systematic reviews and meta-analyses show that training to failure confers, at most, a small hypertrophic advantage over non-failure training, an effect that appears more consistent in resistance-trained individuals than in novices. Emerging dose-response meta-regressions suggest a modest, non-linear relationship between proximity to failure and hypertrophy, while strength gains do not appear to benefit from training closer to failure. Training to failure also carries physiological costs, including greater residual fatigue, slower recovery, and potential interference with volume progression, and repetitions-in-reserve estimation is less accurate when performed farther from failure. We conclude that while training to concentric failure is a valid strategy in specific contexts, particularly for advanced trainees using single-joint exercises on final sets, it is not a prerequisite for hypertrophy and should be applied selectively within a well-structured periodization plan.