Gender difference in subjective muscle-fatigue sensation during sustained muscle force exertion.

Muscle endurance is one of the important composite factors to health-related physical fitness. However, previous measurement techniques for evaluation of isometric muscle endurance have been problematic, including rapid increase of blood pressure and heart rate. The progressive workload method which gradually increases the load can reduce subject's physical and mental burden and is safe even for the elderly. This study aims to examine the relationship between exerted force and subjective muscle-fatigue sensation (SMS) of the antebrachial region as well as differences with respect to gender during sustained static gripping. Subjects consisted of 12 males (age 20.8 +/- 1.6 years) and 15 females (age 20.5 +/- 1.3 years) with no history of neuromuscular disorders. They performed sustained static gripping, in which the demand values are gradually increased: 10 sec for 20% maximal voluntary contraction (MVC), 20 sec each for 30, 40, 50, 60, and 70% MVC, and 10 sec for 80% MVC. Demand values (each %MVC) were determined based on each subject's MVC. The forces exerted during at the demand values of 70-80% MVC were significantly lower in males than in females. A gender difference in SMS between male and female subjects occurred at demand values of 40-60% MVC. In short, even when maintaining the same exertion force during demand values of 40-60% MVC, males may experience greater physical fatigue than females.