Aging reduces the maximal level of peripheral fatigue tolerable and impairs exercise capacity

• DOI: 10.1152/ajpregu.00151.2020
• Publication Date: 2020-09-23T19:19:18Z
• Authors: Slim Zarzissi; Mohamed Amine Bouzid; Firas Zghal; Haithem Rebai; Thomas J. Hureau
• Keywords: Adult; Male; Aging; Exercise Tolerance; Time Factors; Age Factors; Middle Aged; 16. Peace & justice; Quadriceps Muscle; Young Adult; 03 medical and health sciences; 0302 clinical medicine; Muscle Fatigue; Humans; Female; Muscle Strength; Muscle Contraction

The aim of the present study was to determine magnitude maximal level peripheral fatigue attainable (fatigue threshold) during an all-out intermittent isometric knee-extensor protocol in both younger (24 ± 1 yr, n = 12) and older (60 2 participants provide new insights into effects aging on neuromuscular function. Participants performed two experimental sessions, which they 60 voluntary contractions (MVCs; 3 s contraction, relaxation). One trial unfatigued state (CTRL) one other following fatiguing electrical stimulation quadriceps (FNMES). Peripheral quantified via pre/postexercise decrease twitch force (∆Ptw). Critical (CF) determined as mean output last 12 contractions, whereas W' calculated area above CF. Although FNMES led a significant Ptw before performing 60-MVCs (P 0.024), ∆Ptw not different between CTRL for young group 0.491) old 0.523). However, this threshold significantly greater versus (∆Ptw -48 10% vs. -29 13%, respectively, P 0.028). In CTRL, 55 13% lower than < 0.001), but CF similar (326 10 N 322 N, 0.941). correlated with W', independently age (r2 0.84, 0.001). Exercise performance decreases consequent tolerance fatigue. mechanism persists healthy continues play protective role preserving locomotor muscle function exercise.