Forehead Cutaneous Blood Flow in Response to Unloaded Kaatsu Leg Exercise

Abstract

Dynamic exercise induces changes in the redistribution of whole-body organ-tissue blood circulation, including cutaneous blood circulation. We hypothesized that limb exercise combined with restriction of muscular blood flow (Kaatsu) may influence cutaneous blood flow redistribution. PURPOSE: To examine this hypothesis, forehead (supraorbital region) cutaneous blood flow was compared in women performing exercises with and without Kaatsu. METHODS: Ten young and middle-aged (23–47yr) female subjects in the supine position performed three sets of 15 repetitions of unloaded unilateral knee extension exercises (30-s rest between sets). Blood flow was calculated from blood velocity and red blood cell mass (blood flow = velocity * mass) determined by laser blood flowmetry. RESULTS: While exercise without Kaatsu did not induce alterations in velocity and mass (hence, no alterations in blood flow) throughout the entire exercise series, exercise with Kaatsu increased velocity and blood flow in all exercise sets (velocity; 1.17∼1.27 fold, P<0.05, blood flow; 1.22∼1.34 fold, P<0.05, respectively) compared with the velocity and blood flow measurements made before the start of exercise. These increases were not eliminated during the rest periods between exercise sets. Heart rate (HR) increased (P<0.05) with the second and third sets of exercises (64.6±7.0 beats/min, 65.1±7.3 beats/min, respectively) with Kaatsu compared with HR before exercise initiation (59.7±7.3 beats/min), and was higher than the HR resulting from a corresponding set of exercises without Kaatsu. There were no changes in blood lactate and hematocrit in both types of exercises. Norepinephrine increased at the completion of exercise with Kaatsu (0.21±0.08 to 0.30±0.15 pg/ml, P<0.05.). Adrenomedullin, a potent vasorelaxing peptide which induces vasodilation did not show significant alterations at the completion of both types of exercises (without Kaatsu; 13.7±2.2to 14.3±2.1 fmol/ml, with Kaatsu; 13.4±1.8to 13.8±2.0 fmol/ml). CONCLUSION: These results suggest that forehead cutaneous blood circulation was increased by unloaded Kaatsu leg exercise.