Median frequency can be regarded as a valid indicator of local muscle fatigue. As local muscle fatigue develops, the muscle fiber conduction velocity decreases, the fast twitch fibers are recruited less, and consequently the median frequency shifts toward the lower frequency area. The aim of this study was to test the characteristics of the median frequency according to exercise load (30% and 60% of MVC on the biceps brachii, 40% and 80% of MVC on the vastus lateralis) during the fatiguing isometric exercise. Thirteen healthy male volunteer students of Yonsei University were recruited. After the testing maximal voluntary isometric contraction, three variables (initial median frequency, regression slope, fatigue index) from the regression line of MDF data were measured in each exercise load. The results showed that the regression slope and fatigue index were significantly different for the biceps brachii, but not for the vastus lateralis initial MDF was not significant difference according to the exercise load on both muscles. The regression slope and fatigue index could monitor physiologic muscle change during fatiguing isometric exercise. The results showed that two MDF variables reflect the local muscle fatigue according to the exercise load.

본 연구는 등산로의 물리적 특성과 등산시 운동강도와의 관계를 밝히고 이를 이용자관리에 적용할 수 있는 가능성을 제시하고자 수행되었다. 설악산국립공원과 계룡산국립공원을 대상으로 운동부하에 영향을 미치는 등산로의 물리적 특성을 조사한 결과, 경사도가 주요원인이며, 등산시 짐의 무게도 운동부하 증감에 영향을 미치는 것으로 조사되었다. 급경사지에 위치한 등산로의 이용을 억제시킬 수 있는 방안으로 등산로의 연령대별 운동강도를 추정하여 제시하였다. 제시된 홍보자료는 체력이 낮거나 나이가 많은 탐방객의 이용을 억제시킬 수 있을 것으로 판단된다.