This study is aimed to investigate the association between anaerobic․aerobic exercise intensity and hand steadiness. Hand steadiness is the decisive contributor to affecting the job performance just as in the rifle shooting and archery in sports and the microscope-related jobs requiring hand steadiness in industries. In anaerobic exercise condition hand steadiness is measured through hand steadiness tester having 9 different diameter holes after each subject exerts 25%, 50%, 75%, and 100% of maximum back strength. In aerobic exercise occasion it is evaluated at each time heart rate reaches 115%, 130%, and 145% of reference heart rate measured in no task condition after they do jumping jack. The results indicate that an increased intensity in both types of exercise reduces hand steadiness, but hand steadiness at 25% of maximum back strength and 115% of reference heart rate is rather greater than at no exercise. Just as the relation between cognitive stress and job performance has upside-down U form, so does the association of physical loading to hand steadiness, which means that a little exercise tends to improve hand steadiness in comparison with no exercise.

The objective of this study is to investigate the relationship between anaerobic・aerobic exercise intensity and hand steadiness. Based on physiological analysis the conceptual model explaining that both increased anaerobic and aerobic exercise intensity reduce hand steadiness is suggested, which is verified through the experiment with 20 subjects. Hand steadiness is the critical contributor to having an effect on the job performance just as in the rifle shooting and archery in sports, and the microscope-related job requiring hand steadiness in industries, and so forth. In anaerobic exercise experiment the hand steadiness is measured through hand steadiness tester having 9 different diameter holes after each subject exerts 25%, 50%, 75%, and 100% of maximum back strength measured by back muscle dynamometer. In aerobic exercise condition after they do jumping jack, it is evaluated at each time heart rate reaches 115%, 130%, and 145% of reference heart rate measured in no exercise. The findings are that an increased intensity in both types of exercises tend to decrease hand steadiness, but hand steadiness at 25% of maximum back strength and 115% of reference heart rate is rather higher than at no exercise. Just as the association between cognitive stress and job performance has upside-down U form, so does the relation of physical loading to hand steadiness, which means that a little exercise has a tendency to improve hand steadiness compared to one in no exercise condition .