Interscholastic Athletics and Bone Strength: The Iowa Bone Development Study.

ABSTRACT: Pashkova, A, Hartman, JM, Letuchy, EM, and Janz, KF. Interscholastic athletics and bone strength: the Iowa bone development study. J Strength Cond Res 36(5): 1271-1276, 2022-The objective of this study was to determine the relationship between adolescents' participation in various interscholastic sports and differences in bone strength outcomes. Subjects (N = 380) were recruited from the Iowa Bone Development Study and categorized based on sport participation into 3 power groups: no-power, low-power, and high-power. Sports such as basketball, cheerleading/poms, gymnastics, volleyball, track, football, tennis, and soccer were considered high-power. Peripheral quantitative computed tomography (pQCT) was used to determine bone measures of polar stress-strain index (measure of torsion strength), cortical content (measure of cortical bone size and area at the 66% tibia site), and bone strength index (measure of compression strength based on total bone density and area at the 4% tibia site). Adjusted pairwise comparison for group least squares means high-power sport participation compared with no-power sport participation showed significant differences in all bone strength outcomes for both men and women (p value < 0.01). There was a significant difference in all bone strength measures between low-power and no-power groups for men (p value < 0.05), but not women. Because of decreasing levels of physical activity in late adolescence, the promotion of high-power sports may be particularly important for optimal bone development in the final years before peak bone mass.

Influence of physical activity on weight status during the first year of college.

Objective: To provide an analysis of weight change in response to physical activity levels among first year college students. Participants: First year students (N = 114) participated during the 2012-2013 academic year. Methods: Using a web-based survey, researchers gathered information on physical activity and weight at three points: twice throughout the fall and once at the end of the spring semesters. Results: Over half (56.25%) of respondents reported weight gain (between 0.45 and 13.61 kg) from baseline to 9-month follow-up. Weight gainers reported an average gain of 4.20 kg. More than half of participants were not meeting minimal recommendations for cardiorespiratory fitness (59.5%) and strength (53.2%) by the end of the first year of college. Conclusion: This research provides support for intervention and implementation of strategies to promote self-regulation in college students during the transition to college. Addressing the importance of physical activity in weight maintenance is beneficial to first year students' well-being.

Self-controlled use of a perceived physical assistance device during a balancing task.

The nature of the relationship between self-controlled conditions and the participant's perception of when and how to use a physical assistance device while practicing a balancing task was examined. Participants in the Self-control group (n= 9) were allowed to decide when to use a balance pole while performing the task, while the Yoked group (n= 9) had no choice regarding pole usage. The Self-control group had immediate performance benefits that persisted on a delayed retention task. Questionnaire results indicated that the Self-control group predominately used the balance pole when attempting a new performance strategy, while the Yoked group reported they would have preferred use of the pole when attempting a new strategy. Results lend support to the assertion that self-controlled conditions facilitate learning because participants can make decisions regarding assistance based on self-generated performance strategy-as relating to their perception of successful movement execution--to a greater extent than under externally controlled conditions.