[Metabolic fatigue and the performance of visual tasks]

The aim of this study was to analyse the effects of different types of metabolic fatigue, induced by anaerobic alactacid, anaerobic lactacid, sub-maximal aerobic, and maximal aerobic efforts, on the performance of a sensory task (peripheral threshold detection), a sensory-motor task (coincidence-anticipation), and a cognitive task (recall in central vision). Each of three experimental groups performed one of the above-mentioned tasks under all types of fatigue. Running bouts on a treadmill were used to induce the different types of fatigue. Results show that performance in peripheral vision improves with all types of effort. For coincidence-anticipation, only constant error is affected by anaerobic alactacid and maximal aerobic efforts; the former producing a change in behavior from lateness to anticipation, whereas the latter significantly reduces lateness. Finally, performance in the cognitive task is significantly disturbed by the maximal aerobic exercise. It is suggested that, while sensory and adaptive behaviors improve with previous physical work, cognitive behavior is handicapped by highly demanding activities, that is, activities requiring aerobic maximal efforts.