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Alannah K.A. McKay, Peter Peeling, David B. Pyne, Nicolin Tee, Marijke Welveart, Ida A. Heikura, Avish P. Sharma, Jamie Whitfield, Megan L. Ross, Rachel P.L. van Swelm, Coby M. Laarakkers, and Louise M. Burke

This study implemented a 2-week high carbohydrate (CHO) diet intended to maximize CHO oxidation rates and examined the iron-regulatory response to a 26-km race walking effort. Twenty international-level, male race walkers were assigned to either a novel high CHO diet (MAX = 10 g/kg body mass CHO daily) inclusive of gut-training strategies, or a moderate CHO control diet (CON = 6 g/kg body mass CHO daily) for a 2-week training period. The athletes completed a 26-km race walking test protocol before and after the dietary intervention. Venous blood samples were collected pre-, post-, and 3 hr postexercise and measured for serum ferritin, interleukin-6, and hepcidin-25 concentrations. Similar decreases in serum ferritin (17–23%) occurred postintervention in MAX and CON. At the baseline, CON had a greater postexercise increase in interleukin-6 levels after 26 km of walking (20.1-fold, 95% CI [9.2, 35.7]) compared with MAX (10.2-fold, 95% CI [3.7, 18.7]). A similar finding was evident for hepcidin levels 3 hr postexercise (CON = 10.8-fold, 95% CI [4.8, 21.2]; MAX = 8.8-fold, 95% CI [3.9, 16.4]). Postintervention, there were no substantial differences in the interleukin-6 response (CON = 13.6-fold, 95% CI [9.2, 20.5]; MAX = 11.2-fold, 95% CI [6.5, 21.3]) or hepcidin levels (CON = 7.1-fold, 95% CI [2.1, 15.4]; MAX = 6.3-fold, 95% CI [1.8, 14.6]) between the dietary groups. Higher resting serum ferritin (p = .004) and hotter trial ambient temperatures (p = .014) were associated with greater hepcidin levels 3 hr postexercise. Very high CHO diets employed by endurance athletes to increase CHO oxidation have little impact on iron regulation in elite athletes. It appears that variations in serum ferritin concentration and ambient temperature, rather than dietary CHO, are associated with increased hepcidin concentrations 3 hr postexercise.

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Marcelo Gonçalves Duarte, Glauber Carvalho Nobre, Thábata Viviane Brandão Gomes, and Rodolfo Novelino Benda

Background: Studies related to the motor performance of children have suggested an interaction between organisms and the environment. Although motor development seems to be similar among people, the behavior is specific to the context that people are part of. Thus, the aim of this study was to compare the fundamental motor skill performance between indigenous (IN) and nonindigenous children. Methods: One hundred and thirteen children (43 IN and 70 nonindigenous children) between 8 and 10 years of age underwent the Test of Gross Motor Development—2. Results: A multivariate analysis showed a significant group main effect on both locomotor (p < .01) and object control (p < .01) performance with large and medium effect sizes (ηp2 values = .57–.40, respectively). The IN showed the highest scores for galloping, hopping, leaping, jumping, sliding, striking a stationary ball, stationary dribbling, catching a ball, kicking, and overhand throwing (p < .01) with small to large effect sizes (ηp2 values = .05–.50). Conclusion: The IN presented the highest levels of performance in fundamental motor skills compared with those of nonindigenous children. Most likely, IN have more opportunities for motor development in the environmental context (i.e., villages) where they live.

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Pierre Van Luchene and Cécile Delens

Background: Starting college or university is a significant life event that can impact students’ physical activity (PA). Social support specific to PA (SSPA) is a social determinant of PA among college and university students. This review had 3 aims: (1) to systematically review studies examining the association between SSPA and PA among students; (2) to examine whether potential associations differed in terms of types or sources of SSPA; and (3) to examine whether any potential associations differed in terms of gender. Methods: Studies were identified using Academic Search Premier, PsycInfo, Sociological Abstracts, and SPORTDiscus. Results: This review included 25 papers. The results suggested that there is a positive association between SSPA and PA among college and university students. Although the importance of different sources of SSPA is not clear, the results suggested that family and friends provide significant SSPA. Conclusions: High variability in measurement methods made it difficult to compare studies and to come to a clear consensus. However, the findings suggested that SSPA may be a determinant of PA. In order to better understand the relationship between SSPA and PA among students, some elements, such as gender, socioeconomic level, and off- or on-campus housing, should be considered in future studies.

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Russell R. Pate, Marsha Dowda, Ruth P. Saunders, Natalie Colabianchi, Morgan N. Clennin, Kerry L. Cordan, Geena Militello, Agnes Bucko, Dwayne E. Porter, and Wm. Lynn Shirley

Background: The prevalence of childhood obesity is higher in economically and socially deprived areas. Higher levels of physical activity reduce the risk of excessive weight gain in youth, and research has focused on environmental factors associated with children’s physical activity, though the term “physical activity desert” has not come into wide use. Methods: This exploratory study operationalized the term “physical activity desert” and tested the hypothesis that children living in physical activity deserts would be less physically active than children who do not. A cross-sectional study design was applied with 992 fifth-grade students who had provided objectively measured physical activity data. Five of 12 possible elements of the built environment were selected as descriptors of physical activity deserts, including no commercial facilities, no parks, low play spaces, no cohesion, and the presence of incivilities. Results: Univariate and multivariate analyses showed that only the absence of parks was associated with less physical activity in children. Conclusion: Children living in a “no park” zone were less active than their counterparts who lived near a park. This study contributes preliminary conceptual and operational definitions of “physical activity desert.” Future studies of physical activity deserts should be undertaken in larger and more diverse samples.

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Mark L. Latash and Vera L. Talis

The authors have presented an unpublished manuscript by Nikolai Aleksandrovich Bernstein written in the form of a diary in 1949. Bernstein focused on the concept of time as a coordinate in four-dimensional space and discussed a variety of issues, including the definition of time, its measurement, time travel, asymmetry of the past and future, and even linguistics. In particular, he offered a definition of life tightly linked to the concept of time. Overall, this manuscript offers a glimpse into Bernstein’s thinking, his sense of humor, and his sarcasm, intimately coupled with the very serious attitude to scientific discourse.

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Kathleen A. Martin Ginis, Amy E. Latimer-Cheung, and Christopher R. West