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The influence of physical fitness and energy expenditure on a simple reaction time task performed during exercise was investigated. Two groups of 10 subjects were used, one was composed of trained middle-distance runners and one of students who had no regular physical training. The subjects performed a simple reaction time task while pedalling on a cycloergometer at different relative power output corresponding to 20, 40, 60, and 80% of their own maximal aerobic power and immediately after exercise. During exercise, the results showed a decrease in cognitive performance for both groups whereas no significant effect was found after exercise. A significant effect of physical fitness on simple reaction time was noted during exercise. The data are interpreted in terms of optimization of performance focusing particularly on the relations between energy cost of the physical task and attentional demand.

Our aim was to analyze how subjects perceive their own physical fitness. In Study 1 the 247 subjects assessed their own fitness, endurance, strength, flexibility, and body composition according to specific category scales. Analyses showed that self-perceived physical fitness was mainly related to perceived cardiovascular endurance. According to sex and age, strength, flexibility, and body composition could have a significant influence. The scores obtained on the five scales were highly correlated, suggesting they were overdetermined by a more general factor assimilated to physical self-worth. In Study 2 the 91 subjects completed the same five scales, the Spiel-berger State-Trait Anxiety Inventory, the Coopersmith Self-esteem Inventory, and the Bem Sex-role Inventory. Results confirmed the hierarchical model of Fox and Corbin (1989) and showed that physical self-worth is related to self-esteem, anxiety, and masculinity.

Ratings of perceived exertion (WE) have been classically suggested as a useful adjunctive measure to standard physiological responses associated with exercise constraints (e.g., Borg, 1970); however, if high correlations could be expected between some physiological variables (heart rate, minute ventilation, or lactate concentration) and perceived exertion, no concrete theory of perceived exertion permits a priori the supposition of a causal relationship between them (e.g., Delignitres & Brisswalter, 1996; Russell, 1997). For one thing, several works have shown the importance of psychological variables in the perception of exertion (e.g., Rejeski, 1985). Among them, the adoption of an association or a dissociation strategy could lead to uerent effects of physiological changes on WE and, consequently, to a positive or a negative evaluation of the task constraints. During exercise of long duration a positive or a negative evaluation could therefore lead to either the continuation or the cessation of the task. This could be particularly important in racewahg where competition rules impose on the subjects maintenance of their walking gait despite the effect of fatigue. Within this framework, an experimental study was conducted on five high-level racewalkers. Oxygen consumption (VOz), heart rate (HR), minute ventilation (VE), lactate concentration (LA), and scores of perceived exertion (WE 6-20 scale) were recorded during a 3-hr. racewalk task conducted at the competition pace (12.2 f 0.5 km . h-I). Oxygen consumption and minute ventilation were assessed during two submaximal tests on a treadmdl before and immediately after the 3-hr. overground walk. The respect of racewalk rules was controlled using a video motion-analysis system with a camera operating at a nominal rate of 50 frames . set.-', i.e., double phase support; knee of the supported leg straight in the vertical position of each stride. Means and standard deviations are presented in Table 1. Despite a sig