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Bone mineral density (BMD) development and maintenance is enhanced with weight-bearing exercise, while bed rest and zero gravity results in BMD loss. The purpose of this study is to determine if BMD is significantly different in female athletes engaged in weight-bearing versus nonweight-bearing sports. Six BMD sites and anthropometric measurements were assessed at 3 equal intervals utilizing 2-way ANOVA’s. Controlling for body-weight, differences in BMD were investigated utilizing ANCOVA. Pearson and Spearman Rank Correlations were utilized to investigate interrelationships between anthropometric, VO₂max, and BMD measurements. Swimmers were taller and heavier with greater percent, body fat. BMD was significantly different between runners and swimmers only at the distal, which was higher for swimmers at 6 months. There was no difference in radial BMD when utilizing ANCOVA, with weight serving as the covariate. Swimming does not appear to be a contraindicated activity for BMD accrual and maintenance.

Research on motivation to participate in physical activity has typically been characterized by an assessment of reasons for involvement at a single point in time. This study examined motives for participating, self-perceptions (perceived success, perceived basketball competence, perceived peer acceptance), and enjoyment several times during a sport season relative to player status (Le., amount of playing time). Female basketball players (N = 141) completed measures of participation motivation, perceptions of physical competence and peer acceptance, success, and enjoyment at preseason, midseason, and end of season. Players were classified as starters, primary substitutes, or secondary substitutes by their coaches based on extent of actual playing time. All athletes were similar in their reasons for participating; these included mastery, friends, team atmosphere, and fitness. However, starters and primary substitutes were higher than secondary substitutes in perceptions of success, basketball competence, peer acceptance, and enjoyment at midseason, and starters were higher than primary and secondary substitutes on perceived basketball competence at end of season. These results suggest that positive self-perceptions and affect experienced in the physical domain are related to players ’ opportunities to demonstrate competence in salient achievement areas.

Based on Harter’s (12,13) competence motivation theory, this study examined the relationship of coaches’ performance feedback and motivational climate with female athletes’ perceived competence, enjoyment, and intrinsic motivation. Female adolescent soccer players (N = 141) completed measures of relevant constructs toward the latter part of their season. Canonical correlation analysis revealed that athletes’ perceptions of greater positive and informational feedback given by coaches in response to successful performance attempts, greater emphasis placed on a mastery climate, and less emphasis placed on a performance climate, were significantly related to greater ability perceptions, enjoyment, and intrinsic motivation. Exploratory analyses also showed that the relationship between feedback and the psychosocial outcomes may vary as a function of the perceived motivational climate. Overall, these results suggest that coaching feedback and motivational climate are important contributors to explaining adolescent females’ continued motivation to participate in sport.

This paper describes the effects of exercise training on the somatic, skeletal, and sexual maturation of children. Young athletes of both sexes grow at the same rate and to the same extent as young nonathletes. However, there is evidence that the pubertal development of young female athletes may be delayed. Menarche is more consistently late than either thelarche or pubarche. Genetic and environmental factors are explored in an attempt to determine causative mechanisms. Longitudinal training data are needed for both boys and girls on a variety of physical and hormonal variables. Until such data are available, it is recommended that all children engage in regular physical activity but that maturational progress be monitored in those involved in strenuous competitive training.

Physical exercise is known to regulate energy balance. Important to this regulatory system is the existence of several peptides that communicate the status of body energy stores to the brain and are related to the body fatness including leptin, adiponectin and ghrelin. These hormones assist in regulating energy balance as well as somatic and pubertal growth in children. It appears that rather few studies have investigated the responses of leptin, adiponectin and ghrelin to acute exercise and these studies have demonstrated no changes in these peptides as a result of exercise. Leptin levels are decreased and may remain unchanged advancing from prepuberty to pubertal maturation in young male and female athletes. A limited number of studies indicate that adiponectin levels are not different between prepubertal and pubertal athletes and untrained controls. However, in certain circumstances circulating adiponectin could be increased in young athletes after onset of puberty as a result of heavily increased energy expenditure. Ghrelin levels are elevated in young sportsmen. However, pubertal onset decreases ghrelin levels in boys and girls even in the presence of chronically elevated energy expenditure as seen in young athletes. Ghrelin may also be used as an indicator of energy imbalance across the menstrual cycle in adolescent athletes. There are no studies with high-molecular-weight adiponectin and only very few studies with acylated ghrelin responses to acute exercise and chronic training have been performed in young athletes. Since these forms of adiponectin and ghrelin have been thought to be bioactive forms, further studies with these specific forms of adiponectin and ghrelin are needed. In conclusion, further studies should be conducted to investigate the response of these hormones to acute and chronic negative energy balance to better understand their role in regulating energy balance during growth and maturation in young athletes.