PERIPHERAL FATIGUE DOES NOT INFLUENCE THE ONSET OF FATIGUE IN OLDER ADULTS

Muscular fatigue is the decline in ability of a muscle group to produce force following a contraction. Although older adults are less susceptible to fatigue, they have decreased muscle mass, strength, and contractile ability. Peripheral fatigue is attributed to metabolic buildup, while central fatigue is linked to down-regulation of motor unit firing. Decreased oxygen in the tissue and brain is linked to peripheral and central fatigue, respectively. The purpose of this study was to evaluate the onset of fatigue in older adults and assess alterations in oxygenation within the soleus muscle and prefrontal cortex following a plantar-flexor fatigue protocol. Eleven participants (56.3 ± 7.6 years, 169.5 ± 6.5 cm, 75.3 ± 6.7 kg) were assessed before and after a fatigue protocol consisting of repeated maximal concentric contractions completed until