Background and purposes. Central Sensitization (CS) may occur in patients with Chronic Low Back Pain (CLBP). Functional capacity these patients is limited. However, the association of CLBP with functioning assessed via lifting and aerobic capacity tests has been moderately explained and results are contradictory. Let alone pain response following strenuous exercise. Finally, whether CS is associated with either or both lifting and aerobic capacities is unknown. To analyze the relationship between CS, and lifting and aerobic capacities in patients with CLBP. To describe pain response to strenuous exercise in patients with CLBP. Methods. Cross-sectional observational study. CS, lifting and aerobic capacities, and pain response were respectively measured with Central Sensitization Inventory (CSI), floor-to-waist lifting test, Cardiopulmonary Exercise Test (CPET), and Pain response questionnaire. Statistical analyses:. Stepwise-forward multiple regression with lifting and aerobic capacities (dependent), CSI (independent), physical, work- and disability-related characteristics (covariates);. Paired t-test of pain response before CPET pain to immediately and 24h after, and correlation of the changes with CSI. Results and Conclusion. 43 patients were measured. Higher CSI was associated with lower lifting (r=−0.16) and aerobic capacity (r=−0.06) performance after controlling for confounders. Explained variance were 64% and 42% respectively. Immediate pain response slightly decreased in the low back in response to strenuous exercise whereas it significantly increased in the upper legs; diffuse noxious inhibitory control could possibly explain such change. 24-hr pain response revealed no significant differences. CSI was found to be negatively associated with low back immediate pain response (r=−0.13) change. No conflicts of interest. No funding obtained