Investigators have suggested that opiate peptide hormones released during exercise stress may play an important role in athletic performance or perceived effort. Their enzymatic inactivation in the periphery is of considerable interest since the opiate peptides may be regulated by enkephalin hydrolyzing enzyme (EHA). In this study, the relationship between maximal aerobic capacity (VO_2max) and EHA activity was examined in two distinct fitness groups. When the metabolic capacity was evaluated in whole blood, the unfit subjects metabolized the peptides significantly faster than their fit counterparts. Since the total enzyme activity of the two groups is similar, the difference in metabolism must result from circulating factors in the trained athletes, which slow the rate of peptide inactivation.

Few studies in the sporting realm have been conducted to verify the findings from industrial or organizational settings regarding the strong positive motivational effects of goal setting (Locke et al., 1981). Therefore, the purpose of the present investigation was to determine the effects of three levels of goal difficulty and two levels of feedback on the performance of males undertaking an endurance task. Performance results were analyzed using a 2 x 3 x 2 (feedback x goal difficulty x trials) ANOVA with repeated measures on the last factor. Results indicated a significant goal by trials interaction with both specific difficult goal groups improving from trial one to trial two. The "do best" group showed no significant improvements. It was also found that only the difficult, but not the extremely difficult goal group performed significantly better than the "do best" goal group. No significant differences were found between the two feedback groups. The results are discussed in terms of Locke's (1968) original theory of goal setting.

The purpose of this study was to examine the effects of fatigue on force application and resulting movement patterns during the performance of consecutive chin-ups. Special attention was directed toward relating any fatigue effects to upper limb strength dominance. Twenty male adult subjects each performed one trial. Each trial consisted of consecutive chin-ups. Fatigue caused changes in the movement patterns, duration of movement and force applied through the supporting hands. Throughout the performance greater vertical forces were applied through the dominant upper limb segment with the application of these forces resulting in horizontal displacement of the total body center of gravity toward the dominant hand.