Intermittent fasting combined with resistance training produces similar adaptations to resistance training aloneIntermittent fasting does not hinder muscle growth or strength

BackgroundIntermittent fasting (IF) is increasingly combined with resistance training (RT), yet its effects on RT-specific adaptations remain unclear because previous reviews have mainly focused on body composition and metabolic outcomes.ObjectiveThis exploratory multilevel meta-analysis compared IF combined with RT versus RT alone for training adaptations, including maximal strength, local muscular endurance, hypertrophy-related outcomes, and explosive/high-speed performance.MethodsPubMed, Web of Science, and SPORTDiscus were searched to 10 March 2026. Eligible studies were peer-reviewed English-language randomized parallel-group or crossover interventions comparing IF plus RT with RT alone for at least 4 weeks in generally healthy participants. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool. Hedges’ g values based on between-group change scores were pooled using multilevel random-effects models with cluster-robust variance estimation.ResultsEleven studies involving 303 participants were included. Participants were mostly young adults, with varied training status and body-composition profiles. Interventions lasted 4 weeks to 12 months, most commonly used time-restricted eating/feeding, and generally matched RT programs between arms. IF plus RT produced broadly similar training adaptations to RT alone overall (g = 0.09, 95% CI −0.23 to 0.40). No clear differences were observed for maximal strength, local muscular endurance, site-specific hypertrophy-related outcomes, explosive/high-speed performance, or body-region subgroups.ConclusionCurrent limited evidence does not indicate that IF combined with RT clearly compromises chronic RT-related adaptations when RT and nutritional support are reasonably maintained. Further well-controlled research is warranted.