INTRODUCTION: Susceptibility to muscle fatigue during aging could depend on muscle activation patterns. METHODS: Young (mean age, 22 years) and older (mean age 70 years) men and women completed two fatigue tests of knee extensor muscles using voluntary and electrically stimulated contractions. RESULTS: Older subjects displayed a shift to the left of the torque-frequency relationship and held a sustained voluntary isometric contraction at 50% maximal strength for significantly longer than young (P < 0.001). Young and old showed similar fatigue during electrically induced, intermittent isometric contractions (1-s on, 1-s off for 2 min), but women fatigued less than men (P = 0.001). Stronger muscles fatigued more quickly, and slower contractile properties were associated with longer sustained contractions. CONCLUSIONS: The slowing and weakness of older muscle was associated with superior fatigue resistance during sustained isometric contractions. Young and old showed similar fatigue following a series of brief, intermittent contractions, but women fatigued less than men.
INTRODUCTION: Susceptibility to muscle fatigue during aging could depend on muscle activation patterns. METHODS: Young (mean age, 22 years) and older (mean age 70 years) men and women completed two fatigue tests of knee extensor muscles using voluntary and electrically stimulated contractions. RESULTS: Older subjects displayed a shift to the left of the torque-frequency relationship and held a sustained voluntary isometric contraction at 50% maximal strength for significantly longer than young (P < 0.001). Young and old showed similar fatigue during electrically induced, intermittent isometric contractions (1-s on, 1-s off for 2 min), but women fatigued less than men (P = 0.001). Stronger muscles fatigued more quickly, and slower contractile properties were associated with longer sustained contractions. CONCLUSIONS: The slowing and weakness of older muscle was associated with superior fatigue resistance during sustained isometric contractions. Young and old showed similar fatigue following a series of brief, intermittent contractions, but women fatigued less than men.
Authors: Liam Bagley; Mark Slevin; Steven Bradburn; Donghui Liu; Chris Murgatroyd; George Morrissey; Michael Carroll; Mathew Piasecki; William S Gilmore; Jamie S McPhee Journal: BMJ Open Sport Exerc Med Date: 2016-03-04
Authors: Jamie S McPhee; James Cameron; Thomas Maden-Wilkinson; Mathew Piasecki; Moi Hoon Yap; David A Jones; Hans Degens Journal: J Gerontol A Biol Sci Med Sci Date: 2018-09-11 Impact factor: 6.053