title: Effects of age and sex on fatigability and recovery from a sustained maximal isometric voluntary contraction.
abstract: The aim was to assess the effects of sex and age on fatigability and recovery from sustained maximal voluntary contraction (MVC) of the knee extensor muscles. The central (central activation ratio (CAR) and electrical activity amplitude) and peripheral (electrically evoked torque and muscle contractile properties) factors contributing to fatigue and recovery of 24 young adults (12 males) aged 23.2±3.6years and 20 older adults (12 males) aged 70.6±4.4years were compared. The increase in central and peripheral fatigue was greater (p⩽0.01) in the young adults vs the older adults. Sex differences (p=0.002) regarding MVC were attributed to the greater (p<0.01) peripheral fatigue of males vs females. The recovery rate of MVC was greater (p<0.001) in the young adults vs the older adults, with no sex effect. The recovery of MVC was correlated with the CAR in older adults (p=0.001). Thus, the greater endurance observed with age is caused by differences in central and peripheral mechanisms, whereas the greater endurance in females is caused by a difference in a mechanism located within the muscle. The impaired recovery from fatigue in older adults relied more on the recovery of central factors.
authors.affiliation: Institute of Sports Science and Innovations, Lithuanian Sports University, Sporto str. 6, Kaunas, Lithuania. Electronic address: rima.solianik@lsu.lt.
authors.forename: Rima
authors.initials: R
authors.lastname: Solianik
authors.affiliation: Institute of Sports Science and Innovations, Lithuanian Sports University, Sporto str. 6, Kaunas, Lithuania.
authors.forename: Lina
authors.initials: L
authors.lastname: Kreivėnaitė
authors.affiliation: Institute of Sports Science and Innovations, Lithuanian Sports University, Sporto str. 6, Kaunas, Lithuania.
authors.forename: Vytautas
authors.initials: V
authors.lastname: Streckis
authors.affiliation: Institute of Sports Science and Innovations, Lithuanian Sports University, Sporto str. 6, Kaunas, Lithuania.
authors.forename: Dalia
authors.initials: D
authors.lastname: Mickevičienė
authors.affiliation: Institute of Sports Science and Innovations, Lithuanian Sports University, Sporto str. 6, Kaunas, Lithuania.
authors.forename: Albertas
authors.initials: A
authors.lastname: Skurvydas
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D004576:Electromyography; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D007717:Knee / Q000254:growth & development / Q000502:physiology; D008297:Male; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000254:growth & development / Q000502:physiology; D012727:Sex Characteristics; D019415:Torque
keywords: Aging; Central fatigue; Electromyography; Gender; Knee extensor muscles; Peripheral fatigue; Voluntary activation