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Purpose: To evaluate the relative importance and predictive ability of salivary immunoglobulin A (s-IgA) measures with regards to upper respiratory illness (URI) in youth athletes. Methods: Over a 38-week period, 22 youth athletes (age = 16.8 [0.5] y) provided daily symptoms of URI and 15 fortnightly passive drool saliva samples, from which s-IgA concentration and secretion rate were measured. Kernel-smoothed bootstrapping generated a balanced data set with simulated data points. The random forest algorithm was used to evaluate the relative importance (RI) and predictive ability of s-IgA concentration and secretion rate with regards to URI symptoms present on the day of saliva sampling (URI_day), within 2 weeks of sampling (URI_2wk), and within 4 weeks of sampling (URI_4wk). Results: The percentage deviation from average healthy s-IgA concentration was the most important feature for URI_day (median RI 1.74, interquartile range 1.41–2.07). The average healthy s-IgA secretion rate was the most important feature for URI_4wk (median RI 0.94, interquartile range 0.79–1.13). No feature was clearly more important than any other when URI symptoms were identified within 2 weeks of sampling. The values for median area under the curve were 0.68, 0.63, and 0.65 for URI_day, URI_2wk, and URI_4wk, respectively. Conclusions: The RI values suggest that the percentage deviation from average healthy s-IgA concentration may be used to evaluate the short-term risk of URI, while the average healthy s-IgA secretion rate may be used to evaluate the long-term risk. However, the results show that neither s-IgA concentration nor secretion rate can be used to accurately predict URI onset within a 4-week window in youth athletes.

An external focus of attention and autonomy support are identified as key factors to optimize motor learning; however, research in children is limited. Moreover, research has failed to examine these factors in ecologically valid motor learning settings, like physical education. Therefore, the present study examined the effects of external focus of attention when delivered using autonomy-supportive or controlling instructional language on children’s motor learning. Thirty-three novice participants (10.30 ± 0.52 years) practiced a land-based curling task under supportive (external-focus instructions delivered with supportive language), controlling (external-focus instructions delivered with controlling language), or neutral (external instructions embedded in the task aim) conditions before completing a retention and transfer test. The supportive group produced higher positive affect after practice and greater accuracy in the retention test compared with the other groups. The findings provide support for the OPTIMAL (optimizing performance through intrinsic motivation and attention for learning) theory of motor learning that combining an external focus and autonomy support conditions improves motor learning.

In this study, we examine the influence of hometown proximity on collegiate athletic recruit performance. The geographic proximity of a new recruit’s local community to a recruiting organization can influence the recruit’s performance after joining an organization. However, the direction of the effect of such proximity is not clear. Previous research suggests that human resource proximity facilitates recruits’ social embeddedness in the community in and around the recruiting organization. In turn, proximity may increase recruit performance by facilitating learning, trust-building, and social commitment. However, prior research also suggests that proximity could have some negative influences. Our empirical analysis of collegiate basketball recruits suggests that the geographic proximity of an organization to a new recruit’s hometown generally has a positive influence on both individual and team performance. However, proximity may become a disadvantage when there is a disruptive, involuntary coaching change after the recruit joins the organization.