Purpose : To investigate the cooling effect on muscles prior to continuous isometric muscle contraction. Furthermore, tissue compliance, pressure pain threshold, deep tissue temperature, and tissue circulation volume were measured to investigate the cooling effect on a physical reaction. Method : The biceps brachii muscle was contracted isometrically and continuously at the 90(-) degree in flexion position with 40% of maximum contraction. The task was ceased when subjects could not keep over 70 degrees of elbow flexion. An injection type cooling stimulator was used on the biceps brachii muscle as a cooling modality. Results : The continuous contraction time in the cooled group increased significantly compared with the control group. In addition, tissue compliance and pressure pain threshold showed significant differences between the two groups. Conclusion : This study suggested that the isometric continuous contraction time in cooled muscles can be extended to 40% of MVC. The inhibition of muscle metabolism, an increase in the pressure pain threshold, and tissue compliance may affect muscle endurance.