Low Muscular Strength, Weight Status, and Metabolic Syndrome in Adolescents: National Health and Nutrition Examination Survey 2011-2014.

PURPOSE: To investigate the association between muscular strength and metabolic syndrome (MetS), with a specific focus on the role of weight status, using a nationally representative sample of US youth. METHODS: The analysis included 409 boys and 415 girls from the 2011 to 2014 National Health and Nutrition Examination Survey between 12 and 18 years of age. The prevalence of MetS was defined using age- and sex-specific criteria for abdominal obesity, elevated triglycerides, blood pressure, fasting glucose, and low high-density lipoprotein (HDL) cholesterol. Strength was assessed via handgrip dynamometer and expressed as age- and sex-specific z scores of relative strength. Low strength was defined as a relative strength below the 25th percentile. Analyses controlled for age, sex, race/ethnicity, physical activity, and weight status. RESULTS: The sample prevalence of MetS was approximately 5.3%. However, MetS prevalence was 18.5% in overweight/obese youth with low strength. The adjusted odds of MetS were 3.1 (95% confidence interval, 1.5-6.3, P < .001) times higher for overweight/obese youth with low strength versus sufficient strength. CONCLUSION: Muscular strength is predictive of adolescent MetS, specifically in those with unhealthy weight status. Approximately one in 5 overweight/obese youth with low strength had MetS. These findings highlight the relevance of muscular strength in youth cardiometabolic morbidities.

Development and Validation of a PACER Prediction Equation for VO2peak in 10- to 15-Year-Old Youth.

Previous progressive aerobic cardiovascular endurance run (PACER) equations were developed to estimate peak oxygen consumption (VO2peak) from data collected during treadmill running. No equation has been developed using VO2peak assessed during the PACER. Purpose: To develop and validate a prediction equation to estimate VO2peak from the PACER in 10- to 15-year-olds. Methods: A sample of 163 youth were recruited to develop (n = 101) and validate (n = 62) a prediction equation. VO2peak was measured using a portable metabolic unit. Regression analysis yielded a prediction equation that included laps, body mass index, and interaction between sex and age. Correlations and repeated-measures analysis of variances were used to compare the measured and estimated VO2peak from the new Scott et al equation and 2 commonly used FitnessGram™ (Mahar et al 2011 and Mahar et al 2018) equations, and the impact of sex on predicted VO2peak. Results: Predicted VO2peak from the Mahar et al 2011 and 2018 equations was significantly lower compared with measured values, and the Scott et al prediction was not different. The Mahar et al 2018 equation tended to overestimate VO2peak in males but worked well for females. The Mahar et al 2011 and Scott et al equations revealed no sex differences. Conclusions: The Scott et al equation resulted in a more accurate estimate of VO2peak, performing equally well for both sexes.

Exploration of parental rewards in incentivizing children's physical activity.

The purpose of this study was to explore the prevalence, varieties, and motivations behind parent-selected incentivization for children's physical activity (PA). Parents (n = 90; 30.0 ± 8.5 years) of children (8.7 ± 2.1 years) completed a web-based survey that included items regarding the use of PA rewards, children's moderate-to-vigorous PA (MVPA, min·week-1), access to electronic devices, and demographic characteristics. Open-ended questions were used to determine the type of activity rewarded, type of reward given, and parents' reasoning for not using PA rewards. Independent sample t-tests were used to determine differences between reward groups (reward and no reward) and parent-reported children's MVPA. Open-ended responses underwent thematic analysis. Over half (55%) of the respondents provided PA rewards. There was no difference between reward groups for MVPA. Parents reported their children having access to various technology modes, including TV, tablets, video game systems, computers, and cellphones. Most of the parents (78.2%) reported restricting their child's technology time in some capacity. Rewarded PAs were thematized as "children responsibilities", "non-sport activity", and "sport". Two themes regarding types of rewards included "tangible" and "nontangible". Two underlying themes as to why parents did not give rewards were deemed "built-in-habit" and "enjoyment". Rewarding children's PA is prevalent among this sample of parents. Substantial variety exists regarding the type of PA incentivized and the type of reward provided. Future studies should explore whether parents use reward structures and how they conceptualize nontangible, electronics-based rewards versus tangible rewards to incentivize children's PA to promote lifelong behavior.

Physical Activity and Cognitive Aspects of Self-Regulation in Preschool-Aged Children: A Systematic Review.

Previous research showed a positive relationship between physical activity and self-regulation in older children and adolescents, but few publications focused on young children. Therefore, the purpose of this review was to examine the impact of physical activity (PA) on the cognitive aspects of self-regulation (inhibition, attention, and working memory, in preschool-aged (3-6 years old) children. The following databases were searched for articles: PubMed, SPORTDiscus, PsycINFO, and ERIC. References of the reviewed papers were screened for the identification of additional articles to be included in the review. Randomized control trials were reviewed to assess the impact of PA interventions on the cognitive aspects of self-regulation. There were six articles included in this review. Each study assessed at least one cognitive aspect of self-regulation [attention (n = 4), working memory (n = 2), and inhibition (n = 5)]. Attention was the only aspect that consistently showed improvement as a result of the PA interventions (4 of 4 studies). Only one study showed a positive impact on working memory and 60% of studies (3 of 5 studies) reported a positive relationship between PA and inhibition. Overall, the findings from this review showed that a consistent relationship only existed between attention and PA. No clear relationships were evident between working memory and inhibition and PA.