Professor Sandra Hunter is an internationally recognised and outstanding exercise scientist with research expertise in sex and age differences in muscle fatigability and endurance performance, effects of stress on neuromuscular function and muscle fatigue, and the neural control and adaptations to neuromuscular control with advanced age and in clinical populations including stroke and diabetes.
Age-related changes to the motor unit and its neural inputs result in impaired neuromuscular function and functional performance in old adults. Changes in function with advanced age include reduced maximal strength and power, slower contractile velocity, and increased fatigability. Fatigability is the acute reduction in force or power of a muscle in response to exercise and can temporarily exacerbate the age-related loss of strength and power in old adults. Aging is also accompanied by increased variability in motor performance within a motor task and between motor tasks that can be exacerbated with fatigue.
This presentation will highlight (1) fatiguing tasks that exhibit large decreases in performance and predictability of performance with advanced aging, and (2) the neural and muscular mechanisms for the increased fatigability that occurs with aging. Understanding how aging affects fatiguing contractions is important because fatigability of limb muscles can limit functional performance in old and very old adults. Furthermore, fatiguing contractions, when accompanied with adequate recovery, lead to neuromuscular overload and adaptations. Neuromuscular adaptations are required for effective strength training to improve muscle performance which in part will offset the decreased strength and power that occurs with advanced age.