Cross-sectional studies have suggested that total and bioavailable testosterone levels are reduced in some male athletes. Such changes may be related to loss of body weight, increased serum cortisol, and/or alterations in LH pulsatile release. To determine how endurance training may affect androgen levels, we measured serum total testosterone, sex hormone-binding globulin, free androgen index, LH, FSH, PRL, cortisol, and weight in 15 previously sedentary males. We also examined pulsatile LH release in a subset of 5 subjects. Over 6 months of training, the men increased weekly running mileage to an average of 56 km/week. Total testosterone and free androgen index levels decreased significantly. PRL and cortisol also decreased, while single sample LH and FSH remained unchanged. There was a significant reduction in weight, which did not correlate with changes in serum testosterone levels. LH pulsatile release was not altered by training in the subset of 5 runners. These data confirm previous findings of physiological reduction in serum testosterone and PRL levels and suggest that the testosterone decrease is not related to changes in LH pulsatile release, weight, or increased serum cortisol levels.
This review concerns human performance on concurrent schedules of reinforcement. Studies indicate that humans match relative behavior to relative rate of reinforcement. Herrnstein's proportional matching equation describes human performance but most studies do not evaluate the equation at the individual level. Baum's generalized matching equation has received strong support with humans as subjects. This equation permits the investigation of sources of deviation from ideal matching and a few studies have suggested variables which control such deviations in humans. While problems with instructional control are raised, the overall findings support the matching law as a principle of human choice.
The present paper documents the etiological importance of physical activity to self‐starvation in animals and suggests similarities between this research area and the literature concerned with some self‐starvation in humans. An activity anorexia is proposed that may account for 38% to 75% of anorexia nervosa. An account of excessive locomotor activity is made in terms of schedule‐induced behavior. A reciprocally interactive effect of activity and food ingestion is taken to explain self‐starvation for animals and activity anorexia in humans. Literature is reviewed which demonstrates that rats and mice self‐starve when they are given access to a running wheel and placed on food restriction. In this paradigm, these animals become excessively active and paradoxically reduce food consumption when compared with control subjects. This evidence and related findings are shown to be consistent with a phylogenetically based model of anorexia. Sociocultural factors are hypothesized to set and maintain the conditions that produce activity anorexia in humans.
This paper addresses the current help-oriented focus of researchers in applied behavior analysis. Evidence from a recent volume of JABA suggests that analytic behavior is at low levels in applied analysis while cure-help behavior is at high strength. This low proportion of scientific behavior is apparantly related to cure-help contingencies set by institutions and agencies of help and the editorial policies of JABA itself. These contingencies have favored the flight to real people and a concern with client gains, evaluation and outcome strategies rather than the analysis of contingencies of reinforcement controlling human behavior. In this regard, the paper documents the current separation of applied behavior analysis from the experimental analysis of behavior. There is limited use of basic principles in applied analysis today and almost no reference to the current research in the experimental analysis of behavior involving concurrent operants and adjunctive behavior. This divorce of applied behavior research and the experimental analysis of behavior will mitigate against progress toward a powerful technology of behavior. In order to encourage a return to analysis in applied research, there is a need to consider the objectives of applied behavior analysis. The original purpose of behavioral technology is examined and a re-definition of the concept of "social importance" is presented which can direct applied researchers toward an analytic focus. At the same time a change in the publication policies of applied journals such as JABA toward analytic research and the design of new educational contingencies for students will insure the survival of analysis in applied behavior analysis.
Two experiments were designed to assess whether depriving rats of food would increase the reinforcement effectiveness of wheel running (Experiment 1) and whether satiation for wheel running would decrease the reinforcement effectiveness of food (Experiment 2). In Experiment 1, a progressive-ratio schedule was used to measure the reinforcement effectiveness of wheel running when rats were deprived or not deprived of food. Completion of a fixed number of lever presses released a brake on a running wheel for 60 s, and the response requirement was systematically increased until the rat stopped pressing or until 8 hr had elapsed. The ratio value reached (and the total number of lever presses) was an inverted-U function of food deprivation (percentage body weight). In Experiment 2, when wheel running preceded test sessions, fewer food-reinforced lever presses were maintained by the progressive-ratio schedule, and responding occurred at a lower rate on a variable-interval schedule. An interpretation of these results is that deprivation or satiation with respect to one event (such as food) alters the reinforcement effectiveness of a different event (such as access to wheel running).
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