Suprasinal fatigue impedes recovery from a low-intensity sustained contraction in old adults

Tejin Yoon
Bonnie A. Schlinder-Delap Mrs., Marquette
Manda Linea Keller, Marquette University
Sandra K. Hunter, Marquette University

Journal of Applied Physiology, Vol. 112, No. 5 (March 2012): 849-858. Publisher Link.

Abstract

This study determined the contribution of supraspinal fatigue and contractile properties to the age difference in neuromuscular fatigue during and recovery from a low-intensity sustained contraction. Cortical stimulation was used to evoke measures of voluntary activation and muscle relaxation during and after a contraction sustained at 20% of maximal voluntary contraction (MVC) until task failure with elbow flexor muscles in 14 young adults (20.9 ± 3.6 years, 7 men) and 14 old adults (71.6 ± 5.4 years, 7 men). Old adults exhibited a longer time to task failure than the young adults (23.8 ± 9.0 min vs. 11.5 ± 3.9 min, respectively, P