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Sara López-Martínez, Mairena Sánchez-López, Montserrat Solera-Martinez, Natalia Arias-Palencia, Rosa M. Fuentes-Chacón and Vicente Martínez-Vizcaíno

Purpose:

Our objective was to analyze the association between different intensities of physical activity (PA), physical fitness, and metabolic syndrome (MS) in young adults.

Methods:

Cross-sectional study including 275 university students, 18–30 years old, from Cuenca, Spain. We evaluated (a) physical activity using accelerometry, (b) aerobic capacity (VO2max), and (c) muscle strength, by a muscle strength index calculated as the sum of the standardized z score of handgrip dynamometry/weight and standing broad jump. An MS index was estimated by summing standardized z scores of waist circumference, ratio of triglycerides to high-density lipoprotein, mean arterial blood pressure, and HOMA-IR.

Results:

The mean scores of MS index and HOMAIR were significantly higher and the VO2max significantly lower for individuals who did not perform 20 min or more per week of vigorous physical activity. However, those who performed 250 min/week of moderate physical activity showed no significant differences in either VO2max or the MS index when compared with individuals who did not perform this level of activity. The MS index was lower in those with medium-high levels of aerobic capacity. In addition, individuals with medium-high levels of muscular fitness showed lower waist circumference and a lower MS index.

Conclusions:

VO2max and muscle strength are negatively associated with metabolic risk. 20-min/week of vigorous physical activity was associated with lower cardiometabolic risk in young adults; moderate physical activity did not show association with lower cardiometabolic risk.

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Kristin Wiens, Kelly Anne Erdman, Megan Stadnyk and Jill A. Parnell

Purpose:

To evaluate dietary supplement use in young Canadian athletes, their motivation for consuming supplements, and their sources of information.

Methods:

A questionnaire tested for content validity and reliability was administered to 567 athletes between the ages of 11 and 25 years from the Canadian athletic community in face-to-face meetings. Demographics and sport variables were analyzed using descriptive statistics. Fisher’s exact tests were used to examine dietary supplementation patterns and sources of information regarding dietary supplement use between categories of gender, age, sport type, and competition level.

Results:

Ninety-eight percent of athletes were taking at least one dietary supplement. Males were more likely to consume protein powder, energy drinks, recovery drinks, branched chain amino acids, beta-alanine, and glutamine (p < .01); supplements typically associated with increased muscle mass. Athletes 11–17 years old focused on vitamin and mineral supplements; whereas, athletes 18–25 years old focused on purported ergogenic supplements. Strength training athletes were more likely to consume creatine, glutamine, and protein powders (p < .02). Reasons for supplement use included to stay healthy, increase energy, immune system, recovery, and overall performance. Primary sources of information were family and friends, coaches, and athletic trainers; with 48% of athletes having met with a dietitian. Preferred means of education included individual consultations, presentations, and the internet.

Conclusions:

The majority of young athletes are using dietary supplements with the belief they will improve performance and health; however, may not always have reliable information. Educational programs using individual consultations and electronic media are recommended for this demographic.

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Tiago M. Barbosa, Jorge E. Morais, Mário J. Costa, José Goncalves, Daniel A. Marinho and António J. Silva

The aim of this article has been to classify swimmers based on kinematics, hydrodynamics, and anthropometrics. Sixty-seven young swimmers made a maximal 25 m front-crawl to measure with a speedometer the swimming velocity (v), speed-fluctuation (dv) and dv normalized to v (dv/v). Another two 25 m bouts with and without carrying a perturbation device were made to estimate active drag coefficient (CD a). Trunk transverse surface area (S) was measured with photogrammetric technique on land and in the hydrodynamic position. Cluster 1 was related to swimmers with a high speed fluctuation (ie, dv and dv/v), cluster 2 with anthropometrics (ie, S) and cluster 3 with a high hydrodynamic profile (ie, CD a). The variable that seems to discriminate better the clusters was the dv/v (F = 53.680; P < .001), followed by the dv (F = 28.506; P < .001), CD a (F = 21.025; P < .001), S (F = 6.297; P < .01) and v (F = 5.375; P = .01). Stepwise discriminant analysis extracted 2 functions: Function 1 was mainly defined by dv/v and S (74.3% of variance), whereas function 2 was mainly defined by CD a (25.7% of variance). It can be concluded that kinematics, hydrodynamics and anthropometrics are determinant domains in which to classify and characterize young swimmers’ profiles.

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Abigail Fisher, John J. Reilly, Colette Montgomery, Louise A. Kelly, Avril Williamson, Diane M. Jackson, James Y. Paton and Stanley Grant

This study examined whether there was a significant seasonal variation in objectively measured habitual physical activity and sedentary behavior in young children. Participants were children who attend nursery in Glasgow, Scotland, and measurements were taken using uniaxial accelerometry over 3 to 6 days. There were small but significant seasonal associations with physical activity and sedentary behavior (ANOVA: p < .001 in both cases). Total physical activity (accelerometry cpm) was significantly lower in spring than in summer, fall, and winter. We also found slight but significant seasonal variations in time spent in low-intensity activity and in moderate-to-vigorous-intensity activity. Sedentary time was significantly lower in summer vs. spring and in fall vs. spring. The present study suggests that seasonality plays only a limited role in physical activity and sedentary behavior in young children in our setting. Single measures of these variables should be adequate for research purposes in the absence of marked seasonal variability. In our sample and setting, the limited degree of seasonality precluded identification of major seasonal barriers to and opportunities for physical activity.

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Camilla Astley, Diego Souza and Marcos Polito

Purpose:

To compare the acute effect of caffeine ingestion on performance in young judo athletes.

Method:

In a randomized double-blind design, eighteen judo athletes (16.1 ± 1.4 yrs.) were evaluated on three nonconsecutive days. On the first day, the special judo fitness test (SJFT) was used as a control session. On the second day, the sample was randomly divided into two equal groups. One group received 4 mg.kg-1 of caffeine (capsule) and the other group received a placebo. After resting for 60 min, the sample performed the SJFT. On the final day of testing, the same procedure was performed but the substance ingested was exchanged between the groups.

Results:

Heart rate (HR) and rating of perceived exertion (RPE) were recorded throughout the applications of the SJFTs. Caffeine ingestion did not induce changes in HR, but reduced the RPE compared with the placebo session (7.0 ± 1.1 vs 8.2 ± 2.0; p < .05), increased the number of throws applied (29.0 ± 2.6 vs 22.1 ± 3.4; p < .01) and reduced the SJFT index (12.2 ± 0.5 vs. 15.7 ± 0.9; p < .001).

Conclusion:

4 mg.kg-1 did not alter HR but improved performance on SJFT in young judo athletes and reduced the RPE.

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Frances E. Cleland

Young children’s (N = 50) divergent movement ability (DMA), which is one aspect of critical thinking in physical education, was examined in this study. Treatment Group A received 20 physical education lessons based on skill themes using indirect teaching styles (n = 16). Twenty lessons based on low-organized games content using direct teaching styles were provided to Treatment Group B (n = 17). No treatment was provided to the control subjects in Group C (n = 17). No significant DMA pretest differences were determined, and the independent variables (i.e., gender, intelligence, creativity, and background of movement experience) examined were not significantly related to subjects’ pretest DMA. A two-way ANOVA and post hoc Scheffe test revealed that Group A’s posttest DMA scores were significantly higher than those for either Group B or Group C, F(2, 47) = 11.7, p < .0001. Young children’s ability to generate different movement patterns (i.e., DMA), therefore, was significantly improved in response to employing critical thinking strategies in physical education.

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Scott Rathwell and Bradley W. Young

emerging adulthood is also a period of life where significant personal and psychosocial development occurs ( Arnett, 2000 ), the study of positive development within emerging adult athlete cohorts has received less empirical attention than younger populations ( Rathwell & Young, 2016 ). The existing

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Melissa Hodge, Mary Hovinga, Kelley Gabriel, Linda Snetselaar, John Shepherd, Linda Van Horn, Victor Stevens, Brian Egleston, Alan Robson, Seungyoun Jung and Joanne Dorgan

This study prospectively investigates associations between youth moderate-to-vigorous-intensity physical activity (MVPA) and body composition in young adult women using data from the Dietary Intervention Study in Children (DISC) and the DISC06 Follow-Up Study. MVPA was assessed by questionnaire on 5 occasions between the ages 8 and 18 years and at age 25-29 years in 215 DISC female participants. Using whole body dual-energy x-ray absorptiometry (DXA), overall adiposity and body fat distribution were assessed at age 25-29 years by percent body fat (%fat) and android-to-gynoid (A:G) fat ratio, respectively. Linear mixed effects models and generalized linear latent and mixed models were used to assess associations of youth MVPA with both outcomes. Young adult MVPA, adjusted for other young adult characteristics, was significantly inversely associated with young adult %fat (%fat decreased from 37.4% in the lowest MVPA quartile to 32.8% in the highest (p-trend = 0.02)). Adjusted for youth and young adult characteristics including young adult MVPA, youth MVPA also was significantly inversely associated with young adult %fat (β=-0.40 per 10 MET-hrs/wk, p = .02) . No significant associations between MVPA and A:G fat ratio were observed. Results suggest that youth and young adult MVPA are important independent predictors of adiposity in young women.

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Mary Jo MacCracken and Robert E. Stadulis

Dynamic balance performance of young children (ages 4, 6, and 8) was assessed in three social situations: alone (only with tester present); coaction (one other child performing at the same time); and spectators (five other observer children present). Within each age and gender, children (N = 120) were classified as of higher or lower comparative skill. Each balance task performed (walking forward and backward on a line, a narrow beam or a wide beam) was classified as representing easier or more difficult tasks for each child individually. Findings (p ≤ .05) indicated that the facilitation effects of social situations strengthened over age, with spectators producing increments in performance for children of higher skill (especially boys) and decrements in performance for the lower skilled children (both boys and girls). Coaction resulted in positive effects regardless of skill level.

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Tara K. Scanlan and Michael W. Passer

Identification of factors influencing expectancies of successful performance in competitive youth sports is important to understanding the way in which children perceive and respond to this evaluative achievement situation. Therefore, in this field study involving 10- to 12-year-old female soccer players, intrapersonal factors affecting players' pregame personal performance expectancies were first identified. Soccer ability and self-esteem were found to be related to personal performance expectancies, but competitive trait anxiety was not Second, the impact of game outcome, the previously mentioned intrapersonal variables, and the interaction of game outcome and intrapersonal variables was examined by determining players' postgame team expectancies in a hypothetical rematch with the same opponent. The postgame findings showed that winning players evidenced higher team expectancies than tying and losing players. Moreover, the expectancies of tying players were low and, in fact, similar to those of losers. The results of this study successfully replicated and extended previous findings with young male athletes.