As the population of adults aged 65 and above is rapidly growing, it is crucial to identify physical and cognitive limitations pertaining to daily living. The aim of the study was to examine the impact of cognitive fatigue on age-related changes in neuromuscular fatigue and associated brain patterns of the prefrontal cortex.
12 younger (20-35 years) and 11 older (65 and above years) females performed intermittent handgrip exercises at 30% maximum voluntary contraction (MVC) until voluntary exhaustion in the absence and presence of a prior 60-minute cognitively demanding task.
Cognitive fatigue was successfully and comparably induced across both the younger and older groups (p<0.001). While neuromuscular fatigue outcomes (i.e., endurance time and rate of strength loss) and muscular responses were similar across groups (all p>0.100), greater decrements in cognitive fatigue-related brain activation (p=0.053) were observed in older adults when compared to younger adults.
Differences in brain activation suggest an age-related compensatory mechanism (i.e., the scaffolding theory of cognitive aging) of the frontal lobe to regulate the effect of cognitive fatigue to maintain neuromuscular performance.
- Mehta, Ranjana Associate Professor