The Effects of Red Versus Blue Lights and Neuroticism on Voluntary Biceps Brachii Muscle Contraction.

This study investigated the effects of red and blue monochromatic lights and neuroticism on athletes' maximal isometric voluntary contraction (iMVC) level of the biceps brachii muscle. During elbow flexion, we measured iMVCs under a white light (control) condition and under red and blue light conditions. Under red light (vs. white and blue), participants demonstrated a greater iMVC level. Further, based on a median split of the athletes' scores on Tatar's Five Factor Personality Inventory, high and low neuroticism groups showed no red light differences, while, in the blue light condition, participants high in neuroticism increased the iMVC level by 4.04% and those low in neuroticism decreased iMVC level by 6.31%. Thus, the effect of colored light on athletes' motor output varied with individual personality differences in neuroticism.