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Humans are fascinated by the bipedal locomotor capacities at both ends of the athletic spectrum—sprinting speed and endurance. Some of the more popular field (eg, soccer, rugby, and lacrosse) and court (eg, basketball, tennis, and netball) sports utilize mixed energy systems requiring an interplay of both maximal sprinting speed (MSS) and maximal aerobic speed (MAS) to meet the high-intensity running demands of varying frequency, duration, intensity, and recovery. Recently, these locomotor capacities have been considered in combination to produce what is called the anaerobic speed reserve (ASR) as part of the locomotor profile concept (MSS, MAS, and ASR). The purpose of this narrative review is to (1) provide an overview of the locomotor profile concept; (2) review the assessment methods for estimating MSS, MAS, and ASR; (3) examine the age-, sex-, and maturity-associated variations in MSS, MAS, and ASR; (4) examine the trainability of MSS, MAS, and ASR in youth athletes; and (5) conclude with the practical applications using principles of long-term athlete development for training the locomotor profile in youth field and court sport athletes. Based on the available data in young male athletes, MSS, MAS, and ASR generally increase with age and across maturity groups and are trainable. Overall, decisions on training need to consider the sport demands, current fitness and maturity status, and targeted training adaptation sought. [ABSTRACT FROM AUTHOR]

We designed grip strength standards for youth by back-extrapolating cutpoints based on weakness at age 65. Existing standards, based on insufficient bone mineral content (BMC), were also compared in a nationally representative sample. Altogether, 6837 participants (n = 2199 [less than or equal to] 18.9 years of age) from the National Health and Nutrition Examination Survey had dominant hand, grip strength assessed. Lambda Mu Sigma regression was used to create percentiles of strength and identify thresholds linked with clinically relevant weakness (CRW) in older adults. Approximately 93% and 75% of young people met standards based on CRW and BMC, respectively. Non-Hispanic white and black youth were more likely to meet grip strength cutpoints. Underweight children were less likely (odds ratios = 0.20 to 0.26), while overweight/obese youth were more likely (1.38 to 2.71), to meet strength standards compared to normal weight. The standards can be used with, or in place of, normative standards when evaluating grip strength.

Interpreting change in Body mass index (BMI) among youth by comparison to growth charts can be difficult because of maturation-related changes. The aim of this paper was to evaluate the utility of several alternative methods for assessing change in BMI among children. Participants included 1,615 children measured for stature and body mass in first grade and then again the following year. A total of 1,101 students were also assessed in eighth grade. Change was examined using BMI percentiles (BMI%), BMI z-scores, "Percent Over BMI" (BMI50), and the Healthy Fitness Zone continuum, also referred to as BMI85. Youth at lower BMI levels at baseline showed a positive mean change in BMI%/z-score, whereas those at higher levels at baseline showed a negative mean change in BMI%/z-score. These patterns were not seen with BMI50 or BMI85. Assessing change in weight by using BMI% may result in bias so researchers are encouraged to use BMI85 as a more appropriate approach.

In children, levels of play, physical activity, and fitness are key indicators of health and disease and closely tied to optimal growth and development. Cardiopulmonary exercise testing (CPET) provides clinicians with biomarkers of disease and effectiveness of therapy, and researchers with novel insights into fundamental biological mechanisms reflecting an integrated physiological response that is hidden when the child is at rest. Yet the growth of clinical trials utilizing CPET in pediatrics remains stunted despite the current emphasis on preventative medicine and the growing recognition that therapies used in children should be clinically tested in children. There exists a translational gap between basic discovery and clinical application in this essential component of child health. To address this gap, the NIH provided funding through the Clinical and Translational Science Award (CTSA) program to convene a panel of experts. This report summarizes our major findings and outlines next steps necessary to enhance child health exercise medicine translational research. We present specific plans to bolster data interoperability, improve child health CPET reference values, stimulate formal training in exercise medicine for child health care professionals, and outline innovative approaches through which exercise medicine can become more accessible and advance therapeutics across the broad spectrum of child health.

In children, levels of play, physical activity, and fitness are key indicators of health and disease and closely tied to optimal growth and development. Cardiopulmonary exercise testing (CPET) provides clinicians with biomarkers of disease and effectiveness of therapy, and researchers with novel insights into fundamental biological mechanisms reflecting an integrated physiological response that is hidden when the child is at rest. Yet the growth of clinical trials utilizing CPET in pediatrics remains stunted despite the current emphasis on preventative medicine and the growing recognition that therapies used in children should be clinically tested in children. There exists a translational gap between basic discovery and clinical application in this essential component of child health. To address this gap, the NIH provided funding through the Clinical and Translational Science Award (CTSA) program to convene a panel of experts. This report summarizes our major findings and outlines next steps necessary to enhance child health exercise medicine translational research. We present specific plans to bolster data interoperability, improve child health CPET reference values, stimulate formal training in exercise medicine for child health care professionals, and outline innovative approaches through which exercise medicine can become more accessible and advance therapeutics across the broad spectrum of child health.

Background: Children spend most of their awake time at school, and it is important to identify individual and school-level correlates of their physical activity (PA) levels. This study aimed to identify the between-school variability in Portuguese children PA and to investigate student and school PA correlates using multilevel modeling. Methods: The sample included 1075 Portuguese children of both sexes, aged 6-10 years, from 24 schools. Height and weight were measured and body mass index (BMI) was estimated. Physical activity was estimated using the Godin and Shephard questionnaire (total PA score was used); cardiorespiratory fitness was estimated with the 1-mile run/walk test. A structured inventory was used to access information about the school environment. A multilevel analysis (level-1: student-level; level-2: school-level) was used. Results: Student-level variables (age, sex, 1-mile run/walk test) explained 7% of the 64% variance fraction of the individual-level PA; however, school context explained approximately 36% of the total PA variance. Variables included in the model (school size, school setting, playground area, frequency and duration of physical education class, and qualification of physical education teacher) are responsible for 80% of the context variance. Conclusions: School environment is an important correlate of PA among children, enhancing children's opportunities for being active and healthy.

In 2015, the Society of Health and Physical Educators of America (SHAPE America) launched 50 Million StrongTM with goals of improving physical literacy, increasing physical activity levels, and encouraging lifelong physical activity among children by the year 2029. Not only are youth sports programs crucial to meeting 50 Million StrongTM goals, but it also requires the purposeful efforts of sport coaches, program administrators, researchers, coach educators, and coach developers. While it is encouraging that research on sport coaching topics appears to be growing, there is still much to learn about how to prepare coaches to provide quality sport experiences for their athletes. Consequently, to further this call, it is crucial to understand the current state of sports coaching research and propose future research needs in the discipline. The purpose of this paper is to identify research needs in sports coaching and coach education/development that assists in achieving the 50 Million StrongTM goals of SHAPE America. Throughout the paper, critical research questions are identified in two main areas: 1) coaches' roles in developing physically literate athletes, and 2) developing coaches in regards to coach learning, the efficacy of coach education, and coach health and well-being. Furthermore, commensurate with other papers in the series commissioned by the SHAPE America Research Consortium, we discuss these areas within a social ecological model to understand the impact of the bi-directional interactions between environmental factors and individual behaviors. [ABSTRACT FROM AUTHOR]

Purpose: The objective of this study was to examine the independent and combined association of physical activity and body mass index (BMI) with blood pressure in youth. Methods: Youth aged 8-18 years from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) with BMI, blood pressure, and physical activity (accelerometer) were included in the analyses. A total of 2585 subjects (1303 males; 47% of all 8- to 18-year-olds) met these criteria. Results: Obese youth had a systolic blood pressure that was 8 mm Hg higher than normal weight youth. A significant interaction between BMI and physical activity on blood pressure was found (P < .001), and group differences among the BMI/activity groups showed that the 3 obese groups and the overweight/least active group had significantly higher systolic blood pressure than the normal weight/active group across all analyses. The overweight/least active and normal weight/least active groups had significantly higher diastolic blood pressure than the normal weight/active group as well. Conclusions: This study showed a significant independent and combined association of BMI and physical activity with blood pressure in youth. Interventions need to focus on the reduction of fatness/BMI as a way to reduce the cardiovascular risk in youth. [ABSTRACT FROM AUTHOR]

In the United States, 17% of children and adolescents are overweight and 20% live in a food insecure household. Previous studies examining the association between household food insecurity and overweight among children have been inconclusive but are limited insofar as they did not assess child-specific measures of food insecurity and overweight. In response, this study examined the association between food insecurity and child overweight status when these variables were measured for the same child using information on children (n = 1031) aged 10-15 y from the Three-City Study. Approximately 8% of the children were food insecure, whereas 50% were either at risk of overweight or overweight. Bivariate analyses indicated that there were no significant differences in the prevalence of at risk of overweight and overweight between food secure and food insecure children. Gender, race, and income showed similar patterns. Results from logistic regression analyses also indicated that the likelihood of being overweight or at risk of overweight was not significantly different for food secure and food insecure children. Although child-specific food insecurity was not associated with overweight in this sample of low-income children, food insecurity and overweight coexist among these low-income children, because ~25% of the food insecure children were overweight. Additional research is needed to explore the potential relationships between food insecurity and overweight and to better inform policy that attempts to address these issues among low-income households with children.