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We examined the relationship between being bullied during childhood and activity of the hypothalamic-pituitary-adrenal (HPA) axis as assessed through repeated measures of salivary cortisol. A non-clinical sample of 154 (74 boys) predominantly Caucasian middle-class 12-year-olds each provided detailed information about their experiences with bullying and six saliva samples were standardized across time and day. Children with a history of child maltreatment, diagnosed psychiatric illness, foster care placement, medication use (psychotropic and oral contraception) and aggression directed toward peers and/or family members were excluded. Using multilevel regression and applying orthogonal polynomial contrasts to model the observed circadian pattern in the data, we found that occasional and frequent verbal peer victimization was associated with hyposecretion of cortisol when controlling for sex, pubertal status, age, depression and anxiety. This relation, however, was moderated by sex. For boys, occasional exposure was associated with higher cortisol levels, whereas for girls exposure was associated with lower cortisol levels. The present study highlights the need to consider the plight of peer-victimized children seriously, as it is associated with alterations to the HPA axis that affect males and females differently, and likely diminishes a person's ability to cope with stress, possibly placing them at risk for psychopathology and ill health.

This is the first study to show that enjoyment for high-intensity interval exercise increases with chronic training. Prior acute studies typically report high-intensity interval training (HIT) as being more enjoyable than moderate continuous training (MCT) unless the high-intensity intervals are too strenuous or difficult to complete. It follows that exercise competency may be a critical factor contributing to the enjoyment of HIT, and therefore building competency through chronic training may be one way to increase its enjoyment. To test this, we randomly assigned sedentary young adults to six weeks of HIT or MCT, and tracked changes in their enjoyment for the exercise. Enjoyment for HIT increased with training whereas enjoyment for MCT remained constant and lower. Changes in exercise enjoyment were predicted by increases in workload, suggesting that strength adaptions may be important for promoting exercise enjoyment. The results point to HIT as a promising protocol for promoting exercise enjoyment and adherence in sedentary young adults.

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ELISA measures of 17 beta-estradiol, estrone conjugates, and testosterone were adapted for fecal and urinary samples from laboratory mice. We will report on validations of these assays and data from interacting males and females. Unconjugated gonadal steroids were consistently measurable in urine and feces of both males and females. Females that were parturient following insemination excreted relatively low levels of urinary testosterone compared to non-parturient females. The results are consistent with evidence that elevated androgens and estrogens are incompatible with intrauterine implantation of fertilized ova, and suggest that steroids in male urine could contribute to pheromonal action. These methods permit repeated noninvasive measurement of steroid activity in this species.