Mental performance as a function of prior exercise and aerobic capacity for pre-pubescent boys

Masters Research - Master of Philosophy (MPhil)The purpose of this study was to determine the effects of various intensities of prior exercise on mental performance and the relationship of mental performance with aerobic fitness of 10-11 year old boys. It was hypothesized that: (i) physical exertion influences mental performance. ; and (ii) varying amounts of physical exertion differentially influence mental performance. Specifically, 60 subjects were divided into three groups on the basis of their performance on a timed run test of 1000 meters. Each student was then subjected to four different levels of physical exertion ⎽0kpm, 300kpm, 450kpm and 600kpm. Immediately after the completion of each treatment level, mental performance was measured using each of three mental tasks with two levels of complexity: ⎽ (i) 30 addition/subtraction problems. ; (ii) 20 item trial based on the Primary Mental Abilities Spatial Relations subtest (Thurstone, 1962). ; and (iii) Digit Span subtest (Weschler, 1944). Speed measures were taken for the Arithmetic and Spatial Relations tests. An IQ score was also assessed for each subject. Results were analysed initially using a 3 X 4 factorial design including IQ as a covariate, Findings indicated that regardless of task complexity, the treatment level of amount of exertion was having a significant effect on performance for almost all task measures. IQ accounted for a significant difference on performance for Digit Span only. Results were then submitted to factor analysis with four clear factors resulting, designated by their content as: (i) Arithmetic ability. ; (ii) Spatial ability. ; (iii) Auditory memory. ; and (iv) Speed. These four factors were then submitted to analysis of covariance with repeated measures on treatment. Significant results were analysed by Neuman Keuls procedure. It was found that: (i) both cognitive and perceptual aspects of mental performance were facilitated by physical arousal. ; (ii) there was an optimal level of physical exertion in terms of the beneficial effects on mental performance. ; and (iii) this optimal level was significantly related to fitness level (as determined by run time), those at a low level of fitness deteriorating at an earlier point