Pediatric Exercise Science最新文献

Purpose: To examine the effect of normobaric hypoxia on pulmonary oxygen uptake (V˙O2) and muscle oxygenation kinetics during incremental and moderate-intensity exercise in children.

Methods: Eight prepubertal boys (9-11 y) performed incremental cycle tests to exhaustion in both normoxia and hypoxia (fraction of inspired O2 of 15%) followed by repeat 6-minute transitions of moderate-intensity exercise in each condition over subsequent visits.

Results: Maximal oxygen uptake (V˙O2max) was reduced in hypoxia compared with normoxia (1.69 [0.20] vs 1.87 [0.26] L·min-1, P = .028), although the gas exchange threshold was not altered in absolute terms (P = .33) or relative to V˙O2max (P = .78). During moderate-intensity exercise, the phase II V˙O2 time constant (τ) was increased in hypoxia (18 [9] vs 24 [8] s, P = .025), with deoxyhemoglobin τ unchanged (17 [8] vs 16 [6], P ≥ .28).

Conclusions: In prepubertal boys, hypoxia reduced V˙O2max and slowed V˙O2 phase II kinetics during moderate-intensity exercise, despite unchanged deoxyhemoglobin kinetics. These data suggest an oxygen delivery dependence of V˙O2max and moderate-intensity V˙O2 kinetics under conditions of reduced oxygen availability in prepubertal boys.

Purpose: Inflammation regulation is important for obesity management and prevention of obesity-related diseases. This cross-sectional study aimed to analyze the independent and combined associations of physical activity and screen time with biomarkers of inflammation in children and adolescents with overweight/obesity.

Method: A total of 1289 children and adolescents with overweight/obesity were included from the 2015 to 2018 National Health and Nutrition Examination Survey. Multivariable linear regressions were conducted for the association analyses.

Results: For the independent associations, a negative dose-dependent relationship was demonstrated between physical activity and inflammatory biomarker high-sensitivity C-reactive protein (hsCRP) in adolescents with overweight/obesity (P < .001) but not children; screen time was not associated with hsCRP in both children and adolescents. No significant association was found between physical activity or screen time with other inflammatory biomarkers. For the combined associations, there was an interaction between physical activity and screen time on hsCRP in adolescents with overweight/obesity (P = .014). In addition, the negative association between physical activity and hsCRP was greater in boys compared with girls and in Hispanic and non-Hispanic Black individuals compared with non-Hispanic White individuals.

Conclusion: This study demonstrated a combined association of physical activity and screen time with inflammatory biomarker hsCRP in adolescents with overweight/obesity.

Purpose: This study examined the relationship between parent physical activity (PA) support and children's motor skill development and PA during early childhood and explored the potential moderating effect of child PA and motor skills on these relationships.

Methods: Participants (N = 589, 250 girls, meanage = 4.93 [0.59] y) were part of a larger, longitudinal cohort study. Motor skills were assessed using the Movement Assessment Battery for Children-Second Edition. Moderate to vigorous PA (MVPA) was measured using ActiGraph accelerometers. Five items were used to measure parent support frequency (1 = none, 3 = 3-4 times, 5 = daily). Moderation analyses were conducted to examine the moderating effect of MVPA and motor skills on the relationship between parent support and motor skills and MVPA, respectively.

Results: Parent support was significantly related to motor skills (B = 14.45, P = .007), and child MVPA significantly moderated this relationship (B = -0.17, P = .021). The relationship between parent support and child MVPA did not reach significance (B = 2.89, P = .051); however, motor skills had a significant moderating effect (B = -0.08, P = .022).

Conclusions: These novel findings suggest parent PA support is related to child motor skills and PA during early childhood, but this relationship is context dependent. Child-level characteristics should be considered in future parent PA support research.

Background: Anthracycline-induced cardiotoxicity is a frequent complication that can occur at any stage of treatment, even in survivors.

Objective: To determine maximum aerobic power, quality of life, and left ventricular ejection fraction in childhood cancer survivors treated with anthracyclines.

Design: Cross-sectional, observational study.

Methods: The left ventricular ejection fraction was obtained from the transthoracic echocardiogram report in the medical records. Each patient underwent a 6-minute walk test, assessment of maximum aerobic power on a cycle ergometer, and evaluation of perceived exertion using the EPInfant scale, and finally, their quality of life was evaluated using the pediatric quality of life inventory model.

Results: A total of 12 patients were studied, with an average of 16.2 years of age. All patients exhibited a left ventricular ejection fraction >60%, the mean distance covered in the 6-minute walk test was 516.7 m, and the mean of the maximum aerobic power was 70 W. Low quality of life scores were obtained in the physical and psychosocial aspects. In the Pearson test, a weak correlation without statistical significance was found between all the variables studied.

Conclusions: Simultaneously with the detection of cardiotoxicity in childhood cancer survivors, it is pertinent to perform physical evaluations as physical condition and cardiotoxicity seem to be issues that are not necessarily dependent.

Purpose: Children who are allowed greater independent mobility (IM) are more physically active. This study investigated associations between parents' current travel mode to work, their own IM and school travel mode as a child, and their child's IM.

Methods: Children in grades 4 to 6 (n = 1699) were recruited from urban, suburban, and rural schools in Vancouver, Ottawa, and Trois-Rivières. Parents reported their current travel mode to work, IM, and school travel mode as a child. Children self-reported their IM using Hillman's 6 mobility licenses. Multiple imputation was performed to replace missing data. Gender-stratified generalized linear mixed models were adjusted for child age, parent gender, urbanization, and socioeconomic status.

Results: The older a parent was allowed to travel alone as a child, the less IM their child had (boys: β = -0.09, 95% confidence interval [CI], -0.13 to -0.04; girls: β = -0.09, 95% CI, -0.13 to -0.06). Girls whose parents biked to work (β = 0.45, 95% CI, 0.06-0.83) or lived in Trois-Rivières versus other sites (β = 0.82, 95% CI, -0.43 to 1.21) had higher IM. IM increased with each year of age (boys: β = 0.46, CI, 0.34-0.58; girls: β = 0.38, 95% CI, 0.28-0.48).

Conclusion: Parents who experienced IM later may be more restrictive of their child's IM. This may help explain the intergenerational decline in children's IM.

Purpose: Children's poor levels of physical activity (PA) participation and early-onset vascular aging are identified as global health challenges. Children's guided activity play (GAP)-based PA programs have emerged as effective strategies to improve cardiovascular risk factors and health-related fitness. This study proposes to investigate whether GAP improves children's cutaneous microvascular reactivity and health-related fitness.

Methods: Children's (n = 18; 9.8 [1.5] y) PA during a 5-week (4 d/wk; 1 h/d) GAP program was assessed (accelerometry) with preassessments and postassessments for anthropometric, musculoskeletal fitness, blood pressure, estimated aerobic power, and cutaneous microvascular reactivity.

Results: PA averaged 556 (132) kcal·week-1 at 34.7% (7.5%) time at moderate to vigorous intensity. Resting heart rate (-9.5%) and diastolic blood pressure (-7.8%) were reduced without changes in health-related fitness indices. Cutaneous microvascular reactivity to sodium nitroprusside iontophoresis increased the average perfusion (+36.8%), average cutaneous vascular conductance (+30%), the area under the curve (+28.8%), and a faster rise phase (+40%) of perfusion (quadratic modeling; P ≤ .05). Chi-square and crosstabulation analysis revealed significant association between children's PA levels and sodium nitroprusside average perfusion levels, where children with PA levels ≥205.1 kcal.55 minute-1 were overrepresented in the medium/high levels of sodium nitroprusside perfusion.

Conclusion: A 5-week GAP modified the microvascular reactivity in children without changes in body mass, musculoskeletal fitness, or estimated aerobic power.

Purpose: Examine in preschool-aged children: (1) the associations between parental-reported and device-measured outdoor play (OP) and health indicators of physical, cognitive, and social-emotional development and (2) whether associations were independent of outdoor moderate- to vigorous-intensity physical activity (MVPA).

Methods: This cross-sectional study included 107 participants. Children's OP was measured via a parental questionnaire and the lux feature of accelerometers. Children's growth, adiposity, and motor skills were assessed as physical development indicators. Visual-spatial working memory, response inhibition, and expressive language were assessed as cognitive development indicators. Sociability, prosocial behavior, internalizing, externalizing, and self-regulation were assessed as social-emotional development indicators. Regression models were conducted that adjusted for relevant covariates. Additional models further adjusted for outdoor MVPA.

Results: Parental-reported total OP, OP in summer/fall months, and OP on weekdays were negatively associated (small effect sizes) with response inhibition and working memory. After adjusting for outdoor MVPA, these associations were no longer statistically significant. OP on weekdays was negatively associated with externalizing (B = -0.04; 95% confidence interval, -0.08 to -0.00; P = .03) after adjusting for outdoor MVPA. A similar pattern was observed for device-based measured total OP (B = -0.49; 95% confidence interval, -1.05 to 0.07; P = .09).

Conclusions: Future research in preschool-aged children should take into account MVPA and contextual factors when examining the association between OP and health-related indicators.

Purpose: To describe serum irisin and fibroblast growth factor-21 (FGF-21) concentrations in healthy female adolescents with different training activity patterns and their associations with bone mineral properties and metabolic markers.

Methods: A total of 62 adolescent girls aged 14-18 years were recruited: 22 rhythmic gymnasts, 20 swimmers, and 20 untrained controls. Bone mineral characteristics by dual-energy X-ray absorptiometry, daily energy intake by dietary recall, serum irisin, FGF-21, undercarboxylated osteocalcin, and C-terminal telopeptide of type I collagen were measured in all girls.

Results: Whole body and lumbar spine areal bone mineral density and lumbar spine bone mineral content were higher in the rhythmic gymnasts group compared with swimmers and untrained controls groups (P < .05). Serum irisin, FGF-21, undercarboxylated osteocalcin, and C-terminal telopeptide of type I collagen levels were not significantly different between the groups. In the rhythmic gymnasts group, serum FGF-21 concentration was positively correlated with lumbar spine areal bone mineral density independently of confounding factors (r = .51; P = .027).

Conclusions: Serum irisin and FGF-21 levels were not different between adolescent eumenorrheic girls with different training activity patterns. FGF-21 was positively associated with lumbar spine areal bone mineral density, which predominantly consists of trabecular bone in adolescent rhythmic gymnasts.

Purpose: Anecdotal evidence suggests that children with epilepsy (CWE) are limited in the frequency of their daily physical activity (PA). However, there is limited research utilizing device-based measures of PA. We compared levels of PA and sedentary behavior in CWE (11-15 y) and age- and gender-matched healthy controls.

Method: Participants (n = 60 CWE [25 males, 35 females] and n = 49 controls [25 males, 24 females]) wore a Actigraph accelerometer (GT3X or GT3X+) for 7 consecutive days during waking hours and self-reported their PA and sedentary behaviors. CWE were compared with control children on time spent in different intensities of PA and on self-reported PA and sedentary behavior. Factors associated with PA were analyzed using linear regression.

Results: CWE spent less time in accelerometer assessed light (189.15 vs 215.01 min/d, P < .05) and vigorous PA (35.14 vs 44.28 min/d, P < .05) on weekdays compared with controls. There were no significant differences between CWE and control participants in accelerometer assessed time spent sedentary or time spent in PA on weekends. Among CWE, older children engaged in more reported sedentary behavior and younger children spent more time in most domains of PA (P < .05). Furthermore, CWE reported less PA than controls (P = .006). Sixteen percent of controls met World Health Organization PA guidelines compared with 10% of CWE. There was a positive relationship between accelerometer assessed PA and quality of life for CWE.

Conclusion: CWE spent less time in light and moderate to vigorous PA on weekdays. Further research is needed to understand reasons for these differences.