Burnout is a multidimensional occupational syndrome characterized by emotional exhaustion (EE), depersonalization, and low personal accomplishment. Nurses are particularly vulnerable due to sustained physical, emotional, and organizational stressors. Physical activity (PA) and cardiorespiratory fitness (CRF) have been proposed as protective factors; however, evidence remains inconsistent, and burnout is often analyzed as a single global construct. This review aimed to synthesize evidence on the association between burnout and PA or CRF in nurses, with emphasis on burnout dimensions, underlying mechanisms, epidemiological findings, measurement considerations, and occupational health implications. A literature search was conducted in PubMed, Scopus, Web of Science, and Google Scholar for English-language studies published up to 2025. Observational and interventional studies, as well as systematic reviews, examining burnout in relation to PA or CRF were included. Evidence was synthesized narratively without quantitative meta-analysis. Burnout prevalence among nurses is high, particularly for EE. Most studies demonstrate an inverse association between PA and burnout, with some evidence of dose–response relationships. However, PA is predominantly self-reported, and objective CRF assessment in nurses is scarce. Burnout dimensions are inconsistently analyzed, with many studies relying on total scores rather than dimension-specific evaluation. Mechanistically, PA and CRF may reduce burnout risk through improved stress regulation, autonomic balance, recovery processes, and enhanced functional work capacity. To conclude, PA appears protective against burnout in nurses, whereas the role of objectively measured CRF remains underexplored. Future longitudinal research incorporating dimension-specific burnout analysis and objective CRF assessment is needed to inform targeted occupational health interventions. Med Pr Work Health Saf. 2026;77(3)