Acute Effect of Isokinetic Knee Muscle Contraction at Slow & Fast Speed on Heart Rate & Oxygen Uptake in Middle School Students

Abstract

This study examined the acute effects of isokinetic knee muscle contraction of slow & fast speed (slow; 30°•s-1 , 60°•s-1 and fast; 180°•s-1 , 240°•s-1) on heart rate and oxygen uptake in middle school students. METHODS: Thirty-eight boys without any medical problems were divided into normal (n=18) & obese (n=20) group on the basis of BMI 25 kg•m 2. Its variables were measured at rest, right, middle recovery 2 min, left side, and recovery putted on electrocardiogram and gas analysis. RESULTS: Heart rate were significantly different between 180°•s-1 and the others in normal group and between slow of right side and 180°•s-1 and between 60°•s-1 and 240°•s-1 in left of normal group. Also, there were significantly between 30°•s-1 and fast in left of obese group. Obese group were significantly higher than normal group at rest, right, middle, left side, and recovery at the same point measured between normal and obese. Oxygen uptake were significantly different between slow and fast speed after middle 2 min and right & left side in normal group and significantly between 30°•s-1 and 60°•s-1 and 180°•s-1 and 240°•s-1 in right and left of obese group. Normal group were significantly higher than obese group at rest, right, middle, left side, and recovery measured between normal and obese. CONCLUSIONS: Considering above the result, isokinetic protocol can be applied differently between normal weight and obese group to prevent the injury and/or accident and middle recovery time of left and right side for isokinetic exercise.