Exercise Capacity In Children Research Articles

Cardiopulmonary Exercise Test and Daily Physical Activity in Pediatric Congenital Heart Disease: an Exploratory Analysis

Sedentary lifestyle is reported to be associated with diminished exercise capacity resulting in increased cardiovascular risk in adults with congenital heart disease (CHD). This cross-sectional study examined the association between objectively measured physical activity (PA) and exercise capacity in children and adolescents with CHD. Therefore, 107 patients (13.0 ± 2.7 years, 41 girls) with various CHD performed a cardiopulmonary exercise test (CPET) to quantify their peakV'O2. Moderate-to-vigorous physical activity (MVPA) and daily step count were assessed with “Garmin vivofit jr.®” for 7 consecutive days. For association between PA and (sub-) maximal exercise capacity Spearman's correlation was performed. CHD patients showed almost normal values compared to reference (79.5 ± 17.2% [31.6-138.1] %peakV'O2 predicted) with roughly normal ventilatory anaerobic thresholds (50.6±14.0% [20.3-97.9] %VATV'O2). Step counts are below recommendations (9,304 ± 3,792 steps/day [1,701-20,976]), whereas MVPA data are above recommendations for children with ≥ 60min/day (83.6 ± 34.6 min/day [10.1-190.9]). Spearman's Rho showed significant positive correlations to VATV'O2 (r=0.353, p<0.001), and %VATV'O2 (r=0.307, p=0.001) with similar results regarding MVPA (VATV'O2: r=0.300, p=0.002, and %VATV'O2: r=0.270, p=0.005). Concluding, submaximal exercise capacity and PA correlate positively making both assessments relevant in a clinical setting - PA in the context of cardiovascular prevention and peakV'O2 as the strongest predictor for morbidity and mortality.

(1103) - Impact of Neighborhood Factors on Exercise Capacity in Children with Hypertrophic Cardiomyopathy

(1103) - Impact of Neighborhood Factors on Exercise Capacity in Children with Hypertrophic Cardiomyopathy

The 6-Minute Stepper Test cannot be used to assess the functional exercise capacity in healthy children from 6 to 12 Years Old

Background: Background: Assessing functional exercise capacity in children has become increasingly important. This capacity may be assessed by different tests including submaximal test. The gold standard submaximal test in children is the six-minute walking test (6MWT). The main aim of this study was to establish the concurrent validity of the six-minute stepper test (6MST) to assess the functional exercise capacity. The secondary objectives were to compare the change in cardiorespiratory parameters between 6MST and 6MWT, and to determine the feasibility of the 6MST in healthy children. Methods: 53 healthy children were included in this crossover randomized trial. Subjects underwent the 6MST and 6MWT in a random order. The primary outcome was the number of steps during 6MST and the 6-minute walking distance (6MWD). The secondary outcomes were the pulse oxygen saturation and heart rate. Results: 6MWD and number of steps were not correlated (r=0.103; p=0.46). There was a significantly greater increase (p&lt;0.001) in pulse heart rate values during the 6MWT than the stepper test (46.8 ± 17.5%vs31.1 ± 18.3%). Moreover, no correlation between heart rate changes was found in both tests (r=0.139; p=0.32). Pulse oxygen saturation was clinically unchanged in both tests. All children were able to complete the 6MST. Conclusion: We were not able to demonstrate the concurrent validity of the 6MST to assess the functional exercise capacity. Moreover, 6MST and 6MWT have different cardio-pulmonary demands. However, we found that the 6MST is feasible in healthy children from 6 to 12 years old.

Sports despite masks: no negative effects of FFP2 face masks on cardiopulmonary exercise capacity in children

Face masks were recognized as one of the most effective ways to prevent the spread of the COVID-19 virus in adults. These benefits were extended to children and adolescents. However, the fear of negative consequences from wearing a face mask during physical exercise led to cancellations of physical education lessons. This further decreased the amount of physical activity available to children and adolescents during the pandemic. However, there is little published data on the potential adverse effects of wearing the most effective and partially mandatory FFP2/N95 face masks during PE or physical activity (PA) in this age. Even though the pandemic has been declared as passed by the WHO, the rise of a new pandemic and thus the use of face masks for limiting its spread is inevitable, so we need to be better prepared for alternative options to lockdown and limitation of PA in such a scenario. Twenty healthy children aged 8–10 years performed two identical cardiopulmonary exercise tests as an incremental step test on a treadmill within an interval of 2 weeks, one time without wearing a protective mask and one time wearing an FFP2 mask. The cardiopulmonary exercise parameter and especially the end-expiratory gas exchange for oxygen and carbon dioxide (petO2 and petCO2) were documented for each step, at rest and 1 min after reaching physical exhaustion. Twelve boys (mean age 8.5 ± 1.4 years) and 8 girls (mean age 8.8 ± 1.4 years) showed no adverse events until maximal exertion. The mean parameters measured at peak exercise did not differ significantly between both examinations (mean peak VO2 = 42.7 ± 9.5 vs 47.8 ± 12.9 ml/min/kg, p = 0.097, mean O2pulse 7.84 ± 1.9 ml/min vs. 6.89 ± 1.8, p = 0.064, mean VE/VCO2slope 33.4 ± 5.9 vs. 34.0 ± 5.3, p = 0.689). The only significant difference was the respiratory exchange rate (RER, 1.01 ± 0.08 vs 0.95 ± 0.08, p = 0.004). The measured respiratory gases (end-tidal O2 and CO2) decreased and respectively increased significantly in almost every step when wearing an FFP2 mask. However, these levels were well below hypercapnia and above hypoxia.Conclusion: In this study, no significant differences in the cardiorespiratory function at peak exercise could be discerned when wearing an FFP2/N95 face mask. While the end-tidal values for CO2 increased significantly and the end-tidal values for O2 decreased significantly, these values did never reach levels of hypercapnia or hypoxia. Furthermore, the children terminated the exercise at a lower RER and heart rate (HR) suggesting a subconscious awareness of the higher strain. Since the detrimental effects of limiting sports during the pandemic are well documented, stopping PE lessons altogether because of the minor physiological effects of wearing these masks instead of simply stopping pushing children to perform at their best seems premature and should be reconsidered in the future.What is Known:• Wearing a face mask has an influence on psychological, social, and physiological functions in adults.• Because of the observed effects of wearing face masks in adults, physical activity in children was limited during the pandemic.What is New:• Wearing an FFP2/N95 mask during physical activity did not lead to hypercapnia or hypoxia in children in this study.• Even though end-tidal CO2 values were significantly higher and end-tidal O2 values significantly lower when wearing an FFP2/N95 face mask, no pathological values were reached.

Effects of perioperative exercise on cardiorespiratory endurance in children with congenital heart disease in plateau areas after surgical repair

We aimed to explore the effects of perioperative exercise on cardiorespiratory endurance in children with congenital heart disease (CHD) in plateau areas after surgical repair. Fifty children with CHD in the plateau admitted to our hospital were randomly divided into the exercise and control groups. The exercise group received a perioperative exercise intervention beginning within 24 h postoperatively, while the control group received routine nursing and treatment alone. To assess the 6 min walk distance (6MWD) at baseline and at end of intervention, children participated in a 6-min walk test before cardiac repair and at 1 week after general ward transfer. A subset of children in the study underwent the cardiopulmonary exercise test pre-operatively. The 6MWD of children with CHD at baseline was positively correlated with the peak oxygen uptake pre-operatively. No significant difference was reported in the preoperative baseline data of both groups. The 6MWD of the exercise group was significantly higher than that of the control group. Early exercise therapy after cardiac repair could significantly improve the cardiorespiratory endurance and exercise capacity of children with CHD in plateau areas.

Preterm birth and exercise capacity: what do we currently know?

The long-term cardiopulmonary outcomes following preterm birth during the surfactant era remain unclear. Respiratory symptoms, particularly exertional symptoms, are common in preterm children. Therefore, cardiopulmonary exercise testing may provide insights into the pathophysiology driving exertional respiratory symptoms in those born preterm. This review aims to outline the current knowledge of cardiopulmonary exercise testing in the assessment of children born preterm in the surfactant era. This study is a narrative literature review. Published manuscripts concerning the assessment of pulmonary outcomes using cardiopulmonary exercise testing in preterm children (aged <18 years) were reviewed. Search terms related to preterm birth, bronchopulmonary dysplasia, and exercise were entered into electronic databases, including Medline, PubMed, and Google Scholar. Reference lists from included studies were scanned for additional manuscripts. Preterm children have disrupted lung development with significant structural and functional lung disease and increased respiratory symptoms. The association between these (resting) assessments of respiratory health and exercise capacity is unclear; however, expiratory flow limitation and an altered ventilatory response (rapid, shallow breathing) are seen during exercise. Due to the heterogeneity of participants, treatments, and exercise protocols, the effect of the aforementioned limitations on exercise capacity in children born preterm is conflicting and poorly understood. Risk factors for reduced exercise capacity in those born preterm remain poorly understood; however, utilizing cardiopulmonary exercise testing to its full potential, the pathophysiology of exercise limitation in survivors of preterm birth will enhance our understanding of the role exercise may play. The role of exercise interventions in mitigating the risk of chronic disease and premature death following preterm birth has yet to be fully realized and should be a focus of future robust randomized controlled trials.

Six-minute walk test and factors affecting exercise capacity in children with cystic fibrosis.

This study aimed to compare the result of the six-minute walk test (6MWT) in patients with cystic fibrosis (CF) aged < 20 years old and individuals without CF. In this cross-sectional study, 50 children and adolescents with CF and 20 children and adolescents without CF underwent the 6MWT. Vital signs before and immediately after the 6MWT and six-minute walk distance (6MWD) were evaluated. The mean change in heart rate, percentage of peripheral oxygen saturation (SpO2%), systolic blood pressure, respiratory rate, and dyspnea severity during the 6MWT was significantly higher in patients with CF. In the case group, 6MWD was associated with regular chest physical therapy (CPT) and forced expiratory volume (FEV)> 80%. Patients with CF receiving regular CPT or mechanical vibration and with FEV in the first second > 80% showed better physical capacity during the 6MWT (smaller Sp02% decline and lower dyspnea perception). Children and adolescents with CF have lower physical capacity compared to individuals without CF. CPT and mechanical vibration could be used to increase physical capacity in this population.

Reduced peripheral and respiratory muscle strength in pediatric patients after kidney transplantation.

Reduced muscle strength and low-exercise capacity are well documented in adults, but there are few studies examining those impairments in children and adolescents after kidney transplantation. The objective of this study was to evaluate peripheral and respiratory muscle strength and the association with submaximal exercise capacity in children and adolescents after kidney transplant. Forty-seven patients between six and 18 years of age clinically stable after transplantation were included. Peripheral muscle strength (isokinetic and hand-grip dynamometry), respiratory muscle strength (maximal inspiratory and expiratory pressure), and submaximal exercise capacity (six-minute walk test - 6MWT) were assessed. Patients had a mean age of 13.1 ± 2.7 years and an average of 34 months had elapsed since the transplantation. Flexors of the knee showed a significant reduction in muscle strength (77.3% of predicted) and knee extensors had normal values (105.4% of predicted). Hand-grip strength and maximal respiratory pressures (inspiratory and expiratory) also were significantly lower than expected (p < 0.001). Although distance walked in the 6MWT was significantly lower than predicted (p < 0.001), no significant correlation was found with peripheral and respiratory muscle strength. Children and adolescents after kidney transplantation have reduced peripheral muscle strength of knee flexors, hand-grip, and maximal respiratory pressures. No associations were found between peripheral and respiratory muscle strength and submaximal exercise capacity.

Validation of the 25 level modified shuttle test in children with cystic fibrosis.

To evaluate the validity and reliability of the modified shuttle 25-level test (MST-25) in children with cystic fibrosis (CF). A prospective single center study in clinically stable children with CF. Participants undertook two testing conditions on different days: (1) 2xMST-25 tests; (2) cardiopulmonary exercise test (CPET). Test order was randomized. Nadir oxygen saturation (SpO2 ), peak heart rate (HR), breathlessness (modified Borg), rate of perceived exertion (RPE), energy expenditure (EE) and metabolic equivalents (MET) from the MST-25 and CPET were compared to assess validity, while outcomes from 2xMST-25 tests were compared for reliability. CPET was performed using breath-by-breath analysis and EE from the MST-25 obtained using the SenseWear Armband. Strong correlations were found between MST-25 distance and peak oxygen uptake, peak work and minute ventilation on CPET (all r > 0.7, p < 0.01). Moderate correlations were found between MST-25 distance and CPET for METs (r = 0.5) and HR (r = 0.6). Weak associations between tests were evident for nadir SpO2 (r = 0.1), modified Borg (rs = 0.2) and RPE (rs = 0.2). Test-retest reliability was excellent for MST-25 distance (ICC 0.91), peak EE (ICC 0.99) and peak METs (ICC 0.90). Good reliability was achieved for HR (ICC 0.84) and modified Borg score (ICC 0.77), while moderate reliability for nadir SpO2 (ICC 0.64) and RPE (ICC 0.68) was observed. The MST-25 is a valid and reliable field test for the assessment of exercise capacity in children with CF. The MST-25 can be used to accurately monitor exercise capacity and prescribe exercise training, particularly when CPET is not available.

Lifestyle Intervention Improves Physical Fitness and Quality of Life in Children with Bronchopulmonary Dysplasia

Abstract Background: Exercise capacity in children with bronchopulmonary dysplasia (BPD) is lower compared to healthy peers. We aimed to improve maximal exercise capacity using a combined lifestyle intervention in children with BPD. Methods: This semi-cross-over randomized controlled trial investigated the effects of a combined intervention of high-intensity interval training, healthy diet recommendations, and psychological support in children with BPD. Effects were measured on (sub) maximal exercise capacity, lung function, muscle strength, core stability, physical activity levels, quality of life, fatigue, fear of exercise, caloric intake, energy balance, and body composition using a generalized estimation approach. Results: Fourteen children with BPD, median age 8.0 years (interquartile range: 7.7–8.9), 8 males, participated. At baseline, all patients had peak oxygen (VO2)/kg, forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV1) within normal limits. These parameters did not increase significantly after the intervention compared to the control period (effect size peak VO2/Kg + 3.1 ml/kg/min [95% confidence interval (CI) −0.4–6.7], P = 0.076, FVC z-score + 0.67 [95% CI − 0.1–1.4] P = 0.082, and FEV1 z-score + 0.53 [95% CI − 0.13–1.19] P = 0.117). Peak load and peak ventilation on the maximal cardiopulmonary exercise test and walked distance on the 6-min walking test increased significantly compared to the control period (respectively, +14 watt [95% CI 10–18], P &lt; 0.001, +7 L/min [95% CI 2–12], P = 0.009 and + 45 m [95% CI 1–90], P = 0.046). Both self-reported and parent-reported quality of life improved significantly in five domains (including the physical functioning domain). Conclusion: A 12-week combined lifestyle intervention improved peak load and peak ventilation, walk distance, and quality of life in children with BPD.

Is the six-minute walk test still reliable compared to cardiopulmonary exercise test for exercise capacity in children with congenital heart disease?

We aimed to assess the validity of the six-minute walk test (6MWT) to reflect the functional capacity of children with congenital heart disease (CHD), evaluate a possible correlation between the 6MWT distance with cardiopulmonary exercise test (CPET) variables, as well as to find a cutoff value to stratification the physical fitness in this population. We enrolled 459 children with CHD, 6-18 years old, who performed a complete CPET and 6MWT on the same day in a cross-sectional observational study. Correlations between variables of CPET and six-minute walking distance (6MWD) were analyzed and cutoff values of 6MWD were identified for the classification of the physical fitness in the population. The mean distance ambulated during the 6MWT was 578 ± 65 m, 590 ± 65 m for boys, and 562 ± 62 m for girls (p < 0.001). Both VO2max and %predicted VO2max showed a correlation with the 6MWT distance (r = 0.35, p < 0.001 and r = 0.51, p < 0.001, respectively), and an inverse correlation was found between VE/VCO2 slope and the 6MWT distance (r = -0.31; p < 0.001). There appeared to be a linear association between 6MWD and VO2max up to a 6MWD of approximately 600 m. We divided the population into 4 subgroups (boys <130 cm; boys ≥130 cm; girls <130 cm; girls ≥130 cm), and get the cutoff values (554 m, 617 m, 549 m, 587 m) respectively equivalent to 80% of predicted VO2max. The 6MWT distances of another 102 patients were applied for external verification of the cutoff values. Our study provided evidence on when a 6MWT should be considered as a convincing complementary test in the pediatric population with CHD and explored the classification of exercise tolerance using a 6MWD value. The cut-off values for 6MWD may be qualified as an intervention target for exercise rehabilitation.

Exercise capacity in a cohort of children with congenital heart disease

In patients with congenital heart disease (CHD), reduced exercise capacity can be a predictor for late complications and may be used to guide interventions. Yet, the interpretation of exercise capacity is challenged by changes in body composition during growth. Our aim was to create an overview of disease-specific exercise capacity in children with CHD. We performed a multicentre retrospective study of exercise capacity of CHD patients, aged 6–18 years, tested between January 2001 and October 2018. Sex-specific distribution graphs were made using the LMS method and height to relate to body size. We included all CHD with N > 50, including severe defects (e.g., univentricular heart, tetralogy of Fallot) and “simple” lesions as ventricular septum defect and atrial septum defect. We included 1383 tests of 1208 individual patients for analysis. The peak oxygen uptake (VO2peak, 37.3 ml/min/kg (25th–75th percentile 31.3–43.8)) varied between specific defects; patients with univentricular hearts had lower VO2peak compared with other CHD. All groups had lower VO2peak compared to healthy Dutch children. Males had higher VO2peak, Wpeak and O2pulsepeak than females. Sex- and disease-specific distribution graphs for VO2peak, Wpeak and O2pulsepeak showed increase in variation with increase in height. Conclusion: Disease-specific distribution graphs for exercise capacity in children with CHD from a large multicentre cohort demonstrated varying degrees of reduced VO2peak and Wpeak. The distribution graphs can be used in the structured follow-up of patients with CHD to predict outcome and identify patients at risk.What is Known:• Children with congenital heart disease (COnHD) are at risk to develop heart failure, arrhytmia’s and other complications. Exercise capacity may be an important predictor for outcome in children with ConHD. In children, the interpretation of exercise capacity poses an additional challenge related to physical changes during growth.What is New:• In this report of a multi-center cohort >1300 childrewn with ConHD, we related the changes in exercise capacity to length. We demonstrated that exercise capacity was reduced as compared with healthy children and we observed variation between disease groups. Patients with a univentricular circulation (Fontan) had worse exercise capacity. We constructed disease specific charts of development of exercise capacity throughout childhood, accessible via a web-site. These graphs may help practitioner to guide children with ConHD.

Investigation of dynamic hyperinflation and its relationship with exercise capacity in children with bronchiectasis.

Dynamic hyperinflation (DH) is a major contributor to exercise intolerance in patients with obstructive lung diseases. However, it has not been investigated in children with bronchiectasis (BE). We aimed to investigate dynamic ventilatory responses and their influence on functional exercise capacity in children with BE. Forty children with BE (meanforced expiratory volume in 1 s [FEV1 ] = 78 ± 19%pred) were included. Six-minute walk test (6MWT) was conducted using Spiropalm 6MWT® for evaluating dynamic ventilatory responses including inspiratory capacity (IC), minute ventilation (VE), breathing reserve (BR) and respiratory rate (RR). A decrease of ≥100 ml in IC during exertion was defined as DH. Also, spirometry was performed, and peripheral muscle strength were measured. Twenty patients (50%) developed DH, and four patients (10%) were ventilatory limited (BR < %30) during 6MWT. There was a 176 [100-590] ml decrease in IC after exertion in patients with DH. DH did not correlate to clinical or functional indicators of the disease, except for an increase in RR (∆RR) during exertion. High ∆RR was associated with presence of DH (rpb = 0.390; p < 0.05). Clinical features, peripheral muscle strength, and Spiropalm 6MWT metrics including 6MWT distance did not differ between patients with and without DH. Univariate analysis revealed FVC% (R = 0.340), VEpeak (R = 0.565), quadriceps strength (R = 0.698) and handgrip strength (R = 0.711) were the only predictors of 6MWT distance (p < 0.05). Although DH is common in children with BE, the severity of DH is rather low and may not seem to affect functional exercise capacity. However, peripheral muscle strength was a major contributor to functional exercise capacity.

Are there correlations between lung volume and exercise capacity in children and adolescents with native Ebstein's anomaly?

Abstract Funding Acknowledgements Type of funding sources: None. Background Patients with Ebstein’s Anomaly (EA) represent a wide clinical range with patients needing surgery in infancy and others needing no surgery throughout life. Exercise capacity in EA is often impaired. However, lung function is rarely investigated. Purpose This study examines lung volumes in native EA and their correlation with exercise capacity. Methods This retrospective study investigated 35 children with native EA (14 ± 4 years, 17 female), who underwent a cardiopulmonary exercise test (CPET) including spirometry to examine peak oxygen uptake (peakV’O2), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and its ratio (FEV/FVC). Percentage in peakV’O2 &amp;lt;80% represents a reduced exercise capacity, and values &amp;lt;60% are defined as impaired. Z-scores below -1.64 categorize restrictive (FVC) or obstructive (FEV1/FVC) patterns. To analyse correlations between CPET and lung volumes Spearman’s rank test was performed. Results Reduced exercise capacity was found in 17 children (47%), and further seven (20%) children showed impaired exercise capacity. Seven patients (20%) had a restrictive lung volume pattern and three patients (9%) showed obstructive patterns. One patient showed both. Eleven (92%) patients with an impaired lung function had at least a reduced exercise capacity with a median of 64 [53;73] %predicted. Lung volumes correlate significantly with %peakV’O2 (z-FVC: r=0.500, p=0.002 and z-FEV1: r=0.443, p=0.008). Conclusions Most young patients with native EA have impaired results in exercise capacity and a third has reduced lung volumes. Low lung volumes correlate with worse exercise capacity. Thus, the lung function should also be taken into consideration when looking at the performance of these and medical aftercare.

Cardiopulmonary Function Assessment in Children With Pulmonary Valve Stenosis

ObjectivePulmonary valve (PV) stenosis affects cardiac pulmonary function and exercise performance. A cardiopulmonary exercise test (CPET) combined with a transthoracic echocardiogram (TTE) can measure exercise performance, disease progression, and treatment effects. We assessed the exercise capacity in children with PV stenosis by conducting CPET and TTE.MethodsFrom 2005 to 2021, 84 patients with PV stenosis aged 6–18 years were enrolled; 43 were treated with balloon pulmonary valvuloplasty (BPV) (Group A), and 41 received follow-up care (Group B), and their CPET and pulmonary function test results were compared with 84 healthy, matched individuals (Control). We also conducted TTE to compare the peak pulmonary artery pulse wave velocity and pulmonary valve (PV) area before and after catheterization and follow-up care.ResultsThere were no significant differences among the CPET parameters of the patient groups and controls in anaerobic metabolic equivalent (MET) (group A: 6.44 ± 0.58; group B: 6.28 ± 0.47, control: 6.92 ± 0.39, p = 0.110), peak MET (group A: 9.32 ± 0.74; group B: 9.13 ± 0.63; control: 9.80 ± 0.52, p = 0.263), and heart rate recovery (group A: 28.04 ± 4.70; group B: 26.44 ± 3.43, control:26.10 ± 2.42, p = 0.718). No significant differences were found in the pulmonary functions between the three groups. The pulmonary artery pulse wave velocity significantly decreased after catheterization (3.97 ± 1.50 vs. 1.95 ± 0.94, p < 0.0001), but not after follow-up care (1.67 ± 0.77 vs. 1.75 ± 0.66, p = 0.129). The pulmonary vale area significantly improved in group A (0.89 ± 0.71 vs. 1.16 ± 0.58, p < 0.0001), whereas only insignificant progression of PV stenosis was observed in group B (1.60 ± 0.64 vs. 1.57 ± 0.65, p = 0.110).ConclusionsPatients treated with BPV had a similar exercise capacity with that of patients under follow-up care and the healthy controls. Larger or multi-center studies should be conducted to confirm the physical fitness of pediatric patients with PV stenosis after management.

Effects of Pre-Term Birth on the Cardio-Respiratory Responses to Hypoxic Exercise in Children.

Pre-term birth is associated with numerous cardio-respiratory sequelae in children. Whether these impairments impact the responses to exercise in normoxia or hypoxia remains to be established. Fourteen prematurely-born (PREM) (Mean ± SD; gestational age 29 ± 2 weeks; age 9.5 ± 0.3 years), and 15 full-term children (CONT) (gestational age 39 ± 1 weeks; age 9.7 ± 0.9 years), underwent incremental exercise tests to exhaustion in normoxia (FiO2 = 20.9%) and normobaric hypoxia (FiO2 = 13.2%) on a cycle ergometer. Cardio-respiratory variables were measured throughout. Peak power output was higher in normoxia than hypoxia (103 ± 17 vs. 77 ± 18 W; p < 0.001), with no difference between CONT and PREM (94 ± 23 vs. 86 ± 19 W; p = 0.154). VO2peak was higher in normoxia than hypoxia in CONT (50.8 ± 7.2 vs. 43.8 ± 9.9 mL·kg−1·min−1; p < 0.001) but not in PREM (48.1 ± 7.5 vs. 45.0 ± 6.8 mL·kg−1·min−1; p = 0.137; interaction p = 0.044). Higher peak heart rate (187 ± 11 vs. 180 ± 10 bpm; p = 0.005) and lower stroke volume (72 ± 13 vs. 77 ± 14 mL; p = 0.004) were observed in normoxia versus hypoxia in CONT, with no such differences in PREM (p = 0.218 and >0.999, respectively). In conclusion, premature birth does not appear to exacerbate the negative effect of hypoxia on exercise capacity in children. Further research is warranted to identify whether prematurity elicits a protective effect, and to clarify the potential underlying mechanisms.

Exercise Limitation in Children and Adolescents with Mild-to-Moderate Asthma.

BackgroundChildren with uncontrolled asthma are less tolerant to exercise due to ventilatory limitation, exercise-induced bronchoconstriction (EIB), or physical deconditioning. The contribution of these factors in children with controlled mild-to-moderate asthma is unknown.ObjectiveTo explore the underlying mechanisms of reduced exercise capacity in children with controlled mild-to-moderate asthma.MethodsThis was a cross-sectional study of 45 children and adolescents (age 8–18 years) with controlled mild-to-moderate asthma (asthma control test score 21–25) and 61 age-matched healthy controls. All participants completed a physical activity questionnaire and performed spirometry and cardiopulmonary exercise testing (CPET; maximal incremental protocol). Spirometric indices and CPET parameters were compared between the two groups. The effect of EIB (FEV1 decrease >10% post CPET), ventilatory limitation and physical deconditioning on maximum oxygen uptake (n{mathop {rm{V}}limits^.}nO2peak), was assessed by multivariable linear regression.Results62.2% of children with asthma and 29.5% of controls (P = 0.002) were categorized as inactive. Reduced exercise capacity (n{mathop {rm{V}}limits^.}nO2peak <80%) was noted in 53.3% of asthmatics and 16.4% of controls (P < 0.001). EIB was documented in 11.1% of participants with asthma. Physical deconditioning was noted in 37.8% of children with asthma and in 14.8% of controls (P = 0.013). Physical deconditioning emerged as the only significant determinant of n{mathop {rm{V}}limits^.}nO2peak, irrespective of asthma diagnosis, body mass index, ventilatory limitation and EIB.ConclusionChildren with controlled mild-to-moderate asthma are less tolerant to strenuous exercise than their healthy peers. The decreased exercise capacity in this population should mainly be attributed to physical deconditioning, while the contribution of ventilatory limitation and EIB is rather small.

Influence of haematological profile on the exercise capacity of children with sickle cell disease in Kano

The Exercise Capacity (ExC) of children with sickle cell disease (SCD) may be influenced negatively by both haematological and environmental factors.This study aimed to assessthe influence of haematological profile on the ExC of children with SCD in Kano and to ascertain the safety of conducting 6 minute walk test (6MWT) on those children. In the cross-sectional survey, 162 children were recruited from Murtala Mohammed SpecialistHospital, Kano. Each of them walked to-and-fro for 6 minutes on a 10 meter marked level floor at their own walking pace in order to determine their actual 6 minute walk distance (6MWD). The actual 6MWD was compared with a predicted one in order to determine their ExC. Full blood count was used to evaluate haematological profiles. The data wereanalysed with Pearson product moment correlation and unpaired t test, at a level of significance of p&lt;0.05 using SPSS version 20. Results showed that seventy (70) males (43.2%) and ninety two (92) females (56.8%) with mean age of 10.7±3.27 years took part in the study. The actual 6MWD was 366.20 m ± 59.88m (95%CI=356.91m - 375.49m) which was 59.17% of the predicted one. ExCcorrelated with each of White blood cell count (WBC)(r= - 0.22; p=0.005), Sex (r= - 0.27; p=0.001) and age (r=0.19; p=0.013). None of the participants experienced exercise-induced vaso-occlusive crisis during or immediately after the 6MWT.It was concluded that infection (signified by increased WBC count) and female gender have negative influence on ExC. 6MWT is safe to be performed by children with SCD.

Respiratory muscle strength and exercise capacity of children and adolescents with chronic liver diseases Exercise capacity in liver disease

Introdution: Chronic liver diseases are characterized by inflammatory and fibrotic lesions of the liver that cause systemic complications. These complications can negatively interfere with the respiratory muscle strength and exercise capacity of developing children and adolescents. Objectives: To compare respiratory muscle strength and exercise capacity in children and adolescents with chronic hepatopathy, using reference values from healthy individuals of the same age. Methods: A cross-sectional study was performed. Children and adolescents from 6 to 16 years old with chronic hepatopathies were included. For the evaluation of respiratory muscle strength, the maximal respiratory pressures were measured through manovacuometry. A six-minute walk test was used to assess exercise capacity. The Wilcoxon test was used to verify the difference between the evaluated and predicted values of the distance traveled. Results: In total, 40 subjects were analyzed; 57.5% of the subjects were female, and the subjects had a mean age of 11.68±2.82 years. In the comparison between the measured and predicted maximal respiratory pressures, a difference of -17.71 cmH2O (p&lt; 0.001) was found for the maximal inspiratory pressure, and a difference of -30.68 cmH2O (p&lt; 0.001) was found for the maximal expiratory pressure. Regarding exercise capacity, the measured average distance traveled was 346.46±49.21 m, which was 185.54m (p&lt; 0.001) less than the predicted value. Conclusions: Children and adolescents with chronic liver disease have reduced respiratory muscle function and exercise capacity.

Normative data for the 6-min walk test in 11\u201314\xa0year-olds: a population-based study

BackgroundThe 6-min walk test (6MWT) has become an established measure for assessing exercise capacity in children with chronic diseases. However, little evidence has been provided regarding population-based normal data in healthy children. The main purpose of the study was to provide normative data in a large sample of children.MethodsIn this cross-sectional study, 4352 children between 11 and 14 years were recruited (66% girls). The main outcome measure was the distance walked for six minutes. Sex- and age-specific percentile values (5th, 15th, 25th, 50th, 75th, 85th and 95th) for the 6MWT were created and the differences and correlations were examined by the analysis of variance and Pearson’s coefficient of correlation.ResultsThe mean distance walked in 6 min was 576 ± 93 m in boys and 545 ± 92 m in girls, respectively. The mean walking speed for boys and girls was 98 ± 5 m/min and 91 ± 6 m/min. Older boys and girls performed better, compared to their younger counterparts (p for age < 0.001). The 6MWT was significantly correlated with age (r = 0.24, p < 0.001), height (r = 0.09, p < 0.001), weight (r = − 0.13, p < 0.001) and body-mass index (r = − 0.26, p < 0.001).ConclusionsThis is the first population-based study aiming to provide normative data for the 6MWT in healthy children between 11 to 14 years. Children in lower percentiles are ‘target groups’ for special intervention aiming to enhance the performance.