Robin D. A., et al. Tongue Strength and Endurance: Relation to Highly Skilled Movements. Journal of Speech and Hearing Research 35, no. 6 (December 1992): 1239-45.
Tongue strength and endurance (fatigue) were examined in subjects who have acquired high skill levels with their tongues (supranormal) and in subjects who use the tongue normally. The supranormal groups were trumpet players and high school debaters who were able to speak intelligibly at rates much faster than normal. Hand strength and fatigue were also assessed. Maximal strength was measured by recording how much pressure an individual could exert on an air-filled bulb. Endurance was measured by determining how long subjects could sustain 50% of their maximal pressure. Results showed that maximal strength of the tongue and hand did not differentiate the supranormal subjects from the normal subjects. Hand endurance did not differentiate the subjects either. However, the supranormal groups had significantly longer tongue endurance times than did the normal subjects.