@ Perceptual and Motor Skills 1986Request reprints from Dr. L. McNaughton, POB 1214

Abstract

6 experienced orienteers were subject to a VO?,.. treadmill test, two days prior to undertaking two tests of visual perception. One test was conducted while the subjects were in a rested state while the other was conducted while they were under a state of fatigue. Fat~guc was defined as a state in which the subjects were working at or above the~r anaerobic threshold which had been determined previously from their VO?.,.x test. The tests in both the fatigue and rest condition were of a similar narure, that is, the subjects were presented slides of orienteering checkpoints at regular intervals followed by a slide showing a set of questions which the subjects had to answer verbally. Two sets of slides were employed and these were approximately counterbalanced between both subjects and conditions. Points were awarded for the correct answers and the two conditions were then compared. The Wilcoxon test for two correlated samples was used and showed a significant difference between the fatigue and rest scores at p < 0.05. The data suggest that under the influence of fatigue, an orienteer's ability to perceive visual information is greatly impaired. Observation of long distance runners and orienteers has indicated the difficulty experienced in the late stages of their respective events when faced with a mental task to perform. The apparent impossibility of working out time and distance relationships in the final few kilometers of a marathon or of selecting and carrying out the most efficient route between the last two controls (Table 1 lists a glossary of orienteering terms used in this study) of a 15-kilometer orienteering course, leads to speculation of our intellectual capacities under the influence of fatigue. There is a common belief that mild forms of exercise can be helpful in stimulating the intellect. This is the basis upon which daily periods of physical activity have been introduced into many primary schools in Australia. A study conducted for the South Australian Education Department by Coonan2 at the Hindmarsh Primary School, found that students involved in such activity, covered their normal school work in less time and with better results than those children who did not participate. Little has been done however, to discover the point at which the bout of exercise becomes inhibitory in its effects. The influence of different types of physical fatigue on visual capacity has '