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Effect of 8 Weeks of Incremental Aerobic Training on Inflammatory Mediators, Cardiorespiratory Indices, and Functional Capacity in Obese Children With Bronchial Asthma

Ragab K. Elnaggar, Mohammed A. Shendy, and Mahmoud S. Elfakharany

Purpose: To appraise the effects of incremental aerobic training (IAT) on systemic inflammatory mediators, cardiorespiratory indices, and functional capacity in obese children with bronchial asthma. Methods: This study included 30 children with asthma (age = 8–16 y) allocated randomly into either the control group (n = 15; received the traditional pulmonary rehabilitation program) or IAT group (n = 15; engaged in 8 weeks of IAT in addition to the traditional pulmonary rehabilitation program). The systemic inflammatory mediators (high-sensitivity C-reactive protein and interleukin-6), cardiorespiratory indices (peak oxygen uptake, minute ventilation, maximum heart rate, heart rate recovery at 1 min after exercises, and oxygen pulse), and functional capacity (represented by 6-min walk test) were analyzed pretreatment and posttreatment. Results: A significant reduction in the level of high-sensitivity C-reactive protein and interleukin-6 and increase in peak oxygen uptake, minute ventilation, maximum heart rate, and heart rate recovery at 1 minute after exercises was observed among the IAT group as compared with the control group. In addition, the IAT group covered a longer distance in the 6-minute walk test than the control group, suggesting favorable functional capacity. Conclusion: The study results imply that IAT has the potential to improve the inflammatory profile, cardiorespiratory fitness, and functional capacity of obese children with bronchial asthma.

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The Influence of Age and Maturation on Trajectories of Stretch-Shortening Cycle Capability in Male Youth Team Sports

Mark De Ste Croix, Michal Lehnert, Eliska Maixnerova, Francisco Ayala, and Rudolf Psotta

Purpose: To examine the influence of growth and maturation in the trajectory of stretch-shortening cycle capability. Method: Using a mixed-longitudinal design, absolute and relative leg stiffness and reactive strength index (RSI) were measured 3 times over a 3-year period in 44 youth team-sport players. Maturation was determined as maturity offset and included within the Bayesian inference analysis as a covariate alongside chronological age. Results: Irrespective of age and maturation, there was no change in absolute leg stiffness, however relative leg stiffness decreased over time. Maturation and age reduced this decline, but the decline remained significant (Bayesian factor [10] = 5097, model averaged R 2 = .61). The RSI increased over time and more so in older more mature youth players (Bayesian factor [10] = 9.29e 8, model averaged R 2 = .657). Conclusion: In youth players who are at/post peak height velocity, relative leg stiffness appears to decline, which could have an impact on both performance and injury risk. However, RSI increases during this period, and these data reinforce that leg stiffness and RSI reflect different components of stretch-shortening cycle capability. Practitioners should consider these differences when planning training to maximize stretch-shortening cycle capability during growth and maturation in athletes on the developmental performance pathway.

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Substrate Oxidation Is Altered by Obesity During Submaximal Cycling in Prepubertal and Early Pubertal Children: A Quality Study

Kerri Z. Delaney, Leandra Spatari, Mélanie Henderson, Sylvia Santosa, and Marie-Eve Mathieu

Background: To examine substrate oxidation in prepubertal and early pubertal children as a function of body weight, body composition, and sex during an exhaustive cycling test. Methods: This study included 320 children in prepubertal and early puberty (Tanner stage 1 or 2; n = 188 males) who completed a minimum of 4 stages (2–5 min/stage) of an adapted version of the McMaster exhaustive exercise protocol on an upright cycle ergometer. Substrate utilization, relative to individual VO2peak, was determined using VO2 and VCO2 data, obtained with breath-by-breath gas analysis during exercise. Results: Both peak (mg/kg lean body mass·min) and submaximal lipid oxidation (mg/kg lean body mass·min) were highest (P < .01) in children with healthy weight (HW), then overweight, and lowest in obese (OB). Both females with HW (compared with males with HW) and females with OB (compared with males with OB) had higher (P < .01) peak and submaximal lipid oxidation. In children with OB, fat-free mass correlated positively (P < .01) with submaximal lipid oxidation (r = .50). In contrast, in children with HW and overweight, fat-free mass correlated positively (P < .01) with carbohydrate oxidation (r = .52 and r = .47, respectively). Conclusion: Obesity during childhood may alter substrate oxidation during exercise. These results may have implications in the implementation of exercise programs in prepubertal or early puberty to control adiposity.

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Volume 33 (2021): Issue 1 (Feb 2021)

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Volume 32 (2020): Issue 4 (Nov 2020)

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Cardiometabolic and Perceptual Responses to Body-Weight Resistance High-Intensity Interval Exercise in Boys

Jeanette M. Ricci, Todd A. Astorino, Katharine D. Currie, and Karin A. Pfeiffer

The majority of studies examining children’s responses to high-intensity interval exercise primarily utilized running; however, this modality does not require/include other important aspects of physical activity including muscular fitness. Purpose: To compare acute responses between a body weight resistance exercise circuit (CIRC) and treadmill-based (TM) high-intensity interval exercise. Method: A total of 17 boys (age = 9.7 [1.3] y) completed a graded exercise test to determine peak heart rate, peak oxygen uptake (VO2peak), and maximal aerobic speed. Sessions were randomized and counterbalanced. CIRC required 2 sets of 30-second maximal repetitions of 4 exercises. TM included eight 30-second bouts of running at 100% maximal aerobic speed. Both included 30-second active recovery between bouts. Blood lactate concentration was measured preexercise and postexercise. Rating of perceived exertion, affective valence, and enjoyment were recorded preexercise, after intervals 3 and 6, and postexercise. Results: Participants attained 88% (5%) peak heart rate and 74% (9%) VO2peak for CIRC and 89% (4%) peak heart rate and 81% (6%) VO2peak for TM, with a significant difference in percentage of VO2peak (P = .003) between protocols. Postexercise blood lactate concentration was higher following CIRC (5.0 [0.7] mM) versus TM (2.0 [0.3] mM) (P < .001). Rating of perceived exertion, affective valence, and enjoyment responses did not differ between protocols (P > .05). Conclusion: HR responses were near maximal during CIRC, supporting that this body-weight circuit is representative of high-intensity interval exercise.

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Physical Activity Patterns in Children and Adolescents With Heart Disease

David A. White, Erik A. Willis, Chaitanya Panchangam, Kelli M. Teson, Jessica S. Watson, Brian F. Birnbaum, Girish Shirali, and Anitha Parthiban

Purpose: To quantify the differences in daily physical activity (PA) patterns, intensity-specific volumes, and PA bouts in youth with and without heart disease (HD). Methods: Seven-day PA was measured on children/adolescents with HD (n = 34; median age 12.4 y; 61.8% male; 70.6% single ventricle, 17.7% heart failure, and 11.8% pulmonary hypertension) and controls without HD (n = 22; median age 12.3 y; 59.1% male). Mean counts per minute were classified as sedentary, light, and moderate to vigorous PA (MVPA), and bouts of MVPA were calculated. PA was calculated separately for each hour of wear time from 8:00 to 22:00. Multilevel linear mixed modeling compared the outcomes, stratifying by group, time of day, and day part (presented as median percentage of valid wear time [interquartile range]). Results: Compared with the controls, the HD group had more light PA (33.9% [15%] vs 29.6% [9.5%]), less MVPA (1.7% [2.5%] vs 3.2% [3.3%]), and more sporadic bouts (97.4% [5.7%] vs 89.9% [9.2%]), but fewer short (2.0% [3.9%] vs 7.1% [5.7%]) and medium-to-long bouts (0.0% [1.9%] vs 1.6% [4.6%]) of MVPA. The HD group was less active in the late afternoon, between 15:00 and 17:00 (P < .03). There were no differences between groups in sedentary time. Conclusion: Children/adolescents with HD exhibit differences in intensity-specific volumes, PA bouts, and daily PA patterns compared with controls.

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School-Based Exercise Intervention Improves Blood Pressure and Parameters of Arterial Stiffness in Children: A Randomized Controlled Trial

Sascha Ketelhut, Sebastian R. Ketelhut, and Kerstin Ketelhut

Purpose: To evaluate the effectiveness of a school-based exercise intervention on endurance performance (EP), blood pressure (BP), and arterial stiffness in children. Methods: A total of 105 students (mean age = 8.2 [0.6] y; 51% girls; body mass index = 17.8 [3.0] kg/m2) were randomized to the intervention group (IG, n = 51) and control group (CG, n = 54). During a 37-week experimental period, the IG received an exercise intervention (2 × 45 min/wk) in addition to their regular school physical education class (3 × 45 min/wk). EP, peripheral and central BP, pulse pressure, augmentation pressure, augmentation index, and aortic pulse wave velocity were assessed. Results: Following the intervention, significant changes (P < .05) in EP, peripheral and central systolic BP, pulse pressure, augmentation pressure, augmentation index, and aortic pulse wave velocity were found in the IG. Children in the CG displayed significant changes in peripheral and central diastolic BP. An analysis of the baseline-to-post changes revealed significant between-group differences in EP (P < .001), pulse pressure (P = .028), augmentation pressure (P = .007), and aortic pulse wave velocity (P = .037) that favored the IG and in peripheral and central diastolic BP that favored the CG. Conclusion: The school-based exercise intervention had beneficial effects not only on EP but also on different hemodynamic parameters.

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Age-Related Differences in Perceived Exertion While Walking and Running Near the Preferred Transition Speed

Stacey M. Kung, Philip W. Fink, Stephen J. Legg, Ajmol Ali, and Sarah P. Shultz

Purpose: To investigate whether youth and adults can perceive differences in exertion between walking and running at speeds near the preferred transition speed (PTS) and if there are age-related differences in these perceptions. Methods: A total of 49 youth (10–12 y, n = 21; 13–14 y, n = 10; 15–17 y, n = 18) and 13 adults (19–29 y) completed a walk-to-run transition protocol to determine PTS and peak oxygen uptake. The participants walked and ran on a treadmill at 5 speeds (PTS–0.28 m·s−1, PTS–0.14 m·s−1, PTS, PTS+0.14 m·s−1, PTS+0.28 m·s−1) and rated perceived exertion using the OMNI Perceived Exertion (OMNI-RPE) scale. Oxygen consumption was measured during the walk-to-run transition protocol to obtain the relative intensity (percentage of peak oxygen uptake) at PTS. OMNI-RPE scores at all speeds and percentage of peak oxygen uptake at PTS were compared between age groups. Results: The 10- to 12-year-olds transitioned at a higher percentage of peak oxygen uptake than adults (64.54 [10.18] vs 52.22 [11.40], respectively; P = .035). The 10- to 14-year-olds generally reported higher OMNI-RPE scores than the 15- to 17-year-olds and adults (P < .050). In addition, the 10- to 14-year-olds failed to distinguish differences in OMNI-RPE between walking and running at PTS and PTS+0.14 m·s−1. Conclusions: Children aged 10–14 years are less able to distinguish whether walking or running requires less effort at speeds near the PTS compared with adults. The inability to judge which gait mode is less demanding could hinder the ability to minimize locomotive demands.

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Volume 32 (2020): Issue 3 (Aug 2020)