Exercise Capacity In Children Research Articles

Exercise Capacity and Idebenone Intervention in Children and Adolescents With Friedreich Ataxia

Drinkard BE, Keyser RE, Paul SM, Arena R, Plehn JF, Yanovski JA, Di Prospero NA. Exercise capacity and idebenone intervention in children and adolescents with Friedreich ataxia. Objective To determine the exercise capacity of children and adolescents with Friedreich's Ataxia (FA) and to evaluate the effects of 6 months of idebenone treatment on exercise capacity. Design Exploratory endpoint in a randomized double-blind, placebo-controlled, phase II clinical trial designed to investigate the effects of idebenone on a biomarker of oxidative stress. Setting Exercise physiology laboratory in a single clinical research center. Participants Ambulatory subjects (N=48; age range, 9–17y) with genetically confirmed FA. Intervention Idebenone administered orally 3 times a day for a total daily dose of approximately 5, 15, and 45mg/kg or matching placebo for 6 months. Main Outcome Measures Peak oxygen consumption per unit time (peak VO 2) and peak work rate (WR) were measured during incremental exercise testing at baseline and after treatment. Echocardiography and neurologic assessments were also completed before and after treatment. Results Baseline mean peak VO 2 ± SD was 746±246mL/min (16.2±5.8mL/kg/min), and WR was 40±23W for all subjects. Peak VO 2 and WR were correlated with short guanine-adenine-adenine allele length and neurologic function. Relative left ventricular wall thickness was increased but left ventricular ejection fraction was normal in most subjects; there was no relationship between any exercise and echocardiographic measures. There were no significant changes in mean peak VO 2 or WR after idebenone treatment at any dose level relative to placebo. Conclusions Exercise capacity in children and adolescents with FA was significantly impaired. The basis for the impairment appears to be multifactorial and correlated to the degree of neurologic impairment. Although idebenone has previously been shown potentially to improve features of FA, idebenone treatment did not increase exercise capacity relative to placebo.

Exercise Performance and Activity Level in Children With Transposition of the Great Arteries Treated by the Arterial Switch Operation

The exercise capacity of children after arterial switch for transposition of the great arteries (TGA) is known to be at the lower limit of normal. We aimed to ascertain whether this results from compromised hemodynamics or deconditioning. A total of 17 children with TGA (12 male and 5 female children; age 12.1 + or - 2.0 years) treated with the arterial switch operation were compared with 20 age-matched controls (13 male and 7 female children; age 12.8 + or - 2.4 years) regarding their peak exercise capacity, peak workload, and peak heart rate, as assessed by cycle ergometry. The children's physical activity level was monitored for a 7-day period using a pedometer and diary, and a questionnaire was used to assess physical activity participation and overprotection. The results demonstrated that TGA children showed a significantly reduced peak exercise capacity (47.4 + or - 6.4 vs 41.1 + or - 6.6 ml/kg/min; p <0.05), maximal workload (3.7 + or - 0.5 vs 3.1 + or - 0.6 W/kg; p <0.01), and maximal heart rate (189 + or - 9 vs 180 + or - 14 beats/min; p <0.05) compared to the controls. No significant differences were found in the physical activity pattern or overprotection. In conclusion, given the comparable physical activity level, but reduced exercise capacity in the TGA children, these children most likely fall short in their exercise performance because of restrictive hemodynamics rather than deconditioning from reduced daily life activity.

Exercise capacity of children with pediatric lung disease

Pulmonary function of children with cystic fibrosis (CF) and bronchopulmonary dysplasia (BPD) is similar at rest even though the mechanisms of injury differ. We sought to compare the peak exercise responses in children with BPD versus CF while controlling for pulmonary impairment, nutritional status, gender, age, height, and predicted forced expired volume in 1 second (approximately 73% of predicted). Nine BPD children and 9 CF children underwent spirometry and a progressive exercise test to maximum on a cycle ergometer. There was no difference between groups in body mass percentile (CF:97 +/- 13%, BPD: 98 +/- 11%), peak power output (Wpeak) (CF:67 +/- 19 W, BPD:73 +/- 28 W), % predicted Wpeak (CF:83 +/- 28%, BPD:88 +/- 15%), peak oxygen uptake (VO2peak, CF: 38 +/- 7 ml/kg/min, BPD: 39 +/-6 ml/kg/min), or % predicted VO2peak (CF:99 +/- 16 %, BPD:96 +/- 27%). Children with mild pulmonary impairments are able to achieve a near normal peak power output and a normal VO2peak. Neither the aetiology nor the developmental onset of the process appears to be important influences on VO2peak or Wpeak.

Physical Fitness in Children With End-Stage Renal Disease

Medical advances have allowed the majority of children with ESRD to survive into adulthood. As a result, more attention is being focused on improving the health-related quality of life (HRQOL) for children with ESRD. However, most pediatric ESRD HRQOL studies have highlighted on the psychosocial effects of ESRD, with less attention paid to the physical effects. A few studies have recently measured exercise capacity in children with ESRD in the last 5 years. This article reviews studies that detail the physical components of HRQOL as well as other studies that have started to document the exercise capacity of children with ESRD.

Exercise capacity of a contemporary cohort of children with hypoplastic left heart syndrome after staged palliation☆☆☆

Outcome of staged palliation for hypoplastic left heart syndrome has improved over the past decades. However, only little is known about the exercise capacity of children with palliated hypoplastic left heart syndrome where a systemic right ventricle supports the systemic circulation. The aim of the study was to assess exercise capacity in a contemporary cohort of children with hypoplastic left heart syndrome palliated in a single centre according to a uniform surgical strategy. Standardised cardiopulmonary exercise testing on a treadmill was performed in 46 consecutive hypoplastic left heart patients (median age: 6.0 (4.1-11.4) years). All but one patient reached the anaerobic threshold. Exercise data were compared to normal values obtained with a similar exercise protocol in a large cohort of paediatric volunteers. Oxygen uptake at anaerobic threshold (26.9+/-6.0 ml kg(-1)min(-1); 74.5+/-18.2% of predicted) and maximal oxygen uptake (31.0+/-6.8 ml kg(-1)min(-1); 60.8+/-15.0% of predicted) were significantly reduced compared with controls (P<0.0001 for both). The limitation in exercise capacity was due to an impaired rise in heart rate (158+/-23 bpm; 79.7+/-11.5% of predicted; P<0.0001) and oxygen pulse (4.5+/-1.6 ml per beat; 85.5+/-22.0% of predicted; P<0.0001). Furthermore, respiration during exercise was inefficient with an elevated respiratory rate and reduced maximal tidal volume and minute ventilation at maximal exercise. The exercise capacity of children with hypoplastic left heart syndrome is markedly reduced. Limitations in heart rate increase and stroke volume augmentation are the major contributors to this. An abnormal ventilatory response to exercise also adds to their limitation in exercise tolerance. However, the degree of physical disability does not justify discouraging these patients from school and leisure sports.

Six-minute walking test in children with ESRD: discrimination validity and construct validity

The six-minute walking test (6MWT) may be a practical test for the evaluation functional exercise capacity in children with end-stage renal disease (ESRD). The aim of this study was to investigate the 6MWT performance in children with ESRD compared to reference values obtained in healthy children and, secondly, to study the relationship between 6MWT performance with anthropometric variables, clinical parameters, aerobic capacity and muscle strength. Twenty patients (13 boys and seven girls; mean age 14.1 ± 3.4 years) on dialysis participated in this study. Anthropometrics were taken in a standardized manner. The 6MWT was performed in a 20-m-long track in a straight hallway. Aerobic fitness was measured using a cycle ergometer test to determine peak oxygen uptake left( {mathop {text{V}}limits^cdot {{text{O}}_{text{2peak}}}} right) , peak rate (Wpeak) and ventilatory threshold (VT). Muscle strength was measured using hand-held myometry. Children with ESRD showed a reduced 6MWT performance (83% of predicted, p < 0.0001), irrespective of the reference values used. The strongest predictors of 6MWT performance were haematocrit and height. Regression models explained 59% (haematocrit and height) to 60% (haematocrit) of the variance in 6MWT performance. 6MWT performance was not associated with {mathop {text{V}}limits^cdot {{text{O}}_{text{2peak}}}} , strength, or other anthropometric variables, but it was significantly associated with haematocrit and height. Children with ESRD scored lower on the 6MWT than healthy children. Based on these results, the 6MWT may be a useful instrument for monitoring clinical status in children with ESRD, however it cannot substitute for other fitness tests, such as a progressive exercise test to measure {mathop {text{V}}limits^cdot {{text{O}}_{text{2peak}}}} or muscle strength tests.

Reference values for maximal aerobic exercise capacity in children with cystic fibrosis

Reference values for maximal aerobic exercise capacity in children with cystic fibrosis

P-280 Exercise Capacity in Children with Ventricular Arrhythmias

P-280 Exercise Capacity in Children with Ventricular Arrhythmias

A pilot study of twice-weekly exercise during hemodialysis in children

Few published studies have assessed the exercise capacity and/or the effect of exercise in children receiving maintenance hemodialysis (HD). The aim of this study was to determine if twice-weekly exercise for 1 h during HD could improve exercise capacity in children receiving HD. We assessed lower extremity strength (Biodex; dominant extension peak torque in 60 degrees per second, Newton-meters), grip strength (dynanometer, kilogram) and 6-min walk capacity (yards) in ten children (median age 13.6 years, range 8-25 years) at baseline and after 3 months of twice weekly exercise for 1 h during HD. Baseline assessment revealed a mean (1) Biodex of 70 +/- 32 N-m/s, (2) 6-m walk test of 589 +/- 90 yards and (3) grip strength of 23.2 +/- 10 kg, which were 50% lower than the normal value for healthy controls. Patients demonstrated significant improvements in lower extremity strength and 6-min walk test after 3 months of exercise. Our data show that twice-weekly exercise of a moderate intensity during HD can lead to exercise capacity improvement in 3 months. We identified barriers to and strategies for the successful implementation of intradialytic exercise. We suggest that intradialytic exercise intervention may be effective to improve exercise capacity in children receiving maintenance HD.

Exercise capacity in children after surgical correction of tetralogy of Fallot

Exercise capacity in children after surgical correction of tetralogy of Fallot

Nutritional status body composition and exercise capacity in children with cystic fibrosis

Nutritional status body composition and exercise capacity in children with cystic fibrosis

Cardiorespiratory fitness, exercise capacity and physical activity in children: are we measuring the right thing?

Large prospective cohort studies have consistently shown that physical inactivity and low levels of cardiorespiratory fitness are strong and independent predictors of all-cause and cardiovascular mortality in men and women....

Responsiveness of exercise parameters in children with inflammatory myositis

Juvenile dermatomyositis (DM) is an inflammatory myopathy in which the immune system targets the microvasculature of the skeletal muscle and skin, leading to significant muscle weakness and exercise intolerance, although the precise etiology is unknown. The goal of this study was to investigate the changes in exercise capacity in children with myositis during active and inactive disease periods and to study the responsiveness of exercise parameters. Thirteen children with juvenile DM (mean+/-SD age 11.2+/-2.6 years) participated in this study. Patients performed a maximal exercise test using an electronically braked cycle ergometer and respiratory gas analysis system. Exercise parameters were analyzed, including peak oxygen uptake (VO2peak), peak work rate (Wpeak), and ventilatory anaerobic threshold (VAT). All children were tested during an active period of the disease and during a remission period. From these data, 4 different response statistics were calculated. The children performed significantly better during a remission period compared with a period of active disease. Most exercise parameters showed a very large response. The 5 most responsive parameters were Wpeak, Wpeak (percent predicted), oxygen pulse, VO2peak, and power at the VAT. We found in our longitudinal study that children with active juvenile DM had significantly reduced exercise parameters compared with a remission period. Moreover, we found that several parameters had very good responsiveness. With previously established validity and reliability, exercise testing has been demonstrated to be an excellent noninvasive instrument for the longitudinal followup of children with myositis.

Aerobic and anaerobic exercise capacity in children with juvenile idiopathic arthritis

To compare the aerobic and anaerobic exercise capacity of children with juvenile idiopathic arthritis (JIA) with healthy controls, to determine if there were differences based on disease onset type, and to examine the relationship between aerobic and anaerobic exercise capacity in children with JIA. Sixty-two patients with JIA (mean +/- SD age 11.9 +/- 2.2 years, range 6.7-15.9) participated in this study. Aerobic exercise capacity was measured using a cardiopulmonary exercise test. Anaerobic exercise capacity was measured using the Wingate Anaerobic Exercise Test (WAnT). All patients were able to perform the cardiopulmonary exercise test and WAnT without adverse events. On average, the maximal oxygen uptake (VO(2peak)) and VO(2peak/kg) were 69.8% and 74.8%, respectively, of that predicted compared with healthy controls. Mean +/- SD power was 66.7% +/- 37.2% of that predicted compared with healthy children. Mean +/- SD peak power was 65.5% +/- 43.1% of that predicted compared with healthy children. There were significant differences between subgroups of JIA; the oligoarticular-onset group values did not significantly differ from healthy control values; the polyarticular rheumatoid factor positive-onset subgroup had the greatest impairment in both aerobic and anaerobic exercise capacity. The correlations of mean power and peak power with VO(2peak) were r = 0.884 and r = 0.697, respectively (P < 0.05). This study demonstrates that both the aerobic and anaerobic exercise capacity in children with JIA are significantly decreased. The WAnT might be a valuable adjunct to other assessment tools in the followup of patients with JIA.

Exercise capacity and physical fitness in pediatric dialysis and kidney transplant patients

Studies of exercise capacity in children with chronic kidney disease (CKD) are limited. We tested 25 pediatric kidney transplant (TX) recipients and 15 pediatric dialysis (DX) patients. Nine children in the DX group received kidney transplants and were retested 3 months following surgery (pre/post). Testing involved treadmill testing with measurement of peak oxygen uptake (VO(2peak)), muscle strength, body composition (percent fat), and "field" tests of physical fitness using the FITNESSGRAM, which included the PACER test. Values obtained were compared with gender- and age-based criterion-referenced standards [healthy fitness zone (HFZ)]. The previous day physical activity recall (PDPAR) was used to assess physical activity participation. There were no differences between TX and DX subjects for VO(2peak) and muscle strength measurements, and all values were below the normative values. The TX group achieved significantly higher PACER scores, but only one TX and no DX subjects achieved the HFZ for the PACER test. No improvement in any measures were observed from pre- to post-TX in the nine subjects tested, except for a significant increase in percent fat, which negatively affected the change in muscle strength and VO(2peak). All subjects were physically inactive, with less than 10% of nonschool time being physical activity participation. Pediatric patients with CKD had low exercise capacity, were physically inactive, and gained significant fat weight following TX. Counseling and encouragement for more physical activity is warranted as a part of routine medical care in these children.

Does Mitral Stenosis Impact Exercise Capacity in Children with Mild to Moderate Aortic Stenosis?

PURPOSE: Mild to moderate aortic stenosis does not typically impact exercise capacity in children. The purpose of this study was to determine the impact of mitral stenosis (MS) on exercise capacity in patients with mild to moderate aortic stenosis (AS). METHODS: Isolated mild to moderate AS patients and combined MS/AS patients underwent maximal exercise echocardiography using the James protocol. Subjects with structurally normal hearts (Norm) served as controls. Baseline and peak exercise data and echo valvar gradients were compared using one-way ANOVA and the Bonferroni t procedure. RESULTS: 13 studies in 10 patients with isolated AS (mean age 15.3 years) were compared to 13 studies in 8 patients with combined MS/AS (mean age 14.6 yrs) and 26 normal subjects (mean age 14.2 yrs). Demographics, total working capacity (TWC), maximal systolic blood pressure (SBP) and respiratory quotient (MaxRQ) were not significantly different among the groups. There was no significant change in mean aortic gradient from rest to peak exercise in MS/AS and AS groups (19±11 to 29±9, 25±11 to 24±15mmHg). There was a significant increase in mean mitral gradient from rest to peak exercise in the MS/AS group (5±2 to 16±8 mmHg, p<0.001). The MS/AS group demonstrated a significantly decreased MaxHR compared to Norm and significantly decreased maximal oxygen consumption (MVO2) and cardiac output (MaxQ) compared to both AS and Norm groups.TableCONCLUSION: In pediatric patients with mild to moderate aortic stenosis, the presence of mild mitral stenosis negatively impacts aerobic capacity and cardiac output at peak exercise. This suggests the possibility that mitral stenosis perturbs the adaptive mechanisms utilized by these subjects during peak exercise.

Six-Minute Walk Test in Children and Adolescents

To evaluate the 6-minute walking distance (6MWD) for healthy Caucasian children and adolescents of a population-based sample from the age of 3 to 18 years. Two hundred and eighty boys and 248 girls completed a modified test, using a measuring wheel as incentive device. Median 6MWD increased from the age of 3 to 11 years in boys and girls alike and increased further with increasing age in boys (from 667.3 m to 727.6 m), whereas it essentially plateaued in girls (655.8 m to 660.9 m). After adjusting for age, height (P = .001 in boys and P < .001 in girls) remained independently correlated with the 6MWD. In the best fitting and most efficient linear and quadratic regression models, the variables age and height explained about 49% of the variability of the 6MWD in boys and 50% in girls. This modified 6-minute walk test (6MWT) proved to be safe, easy to perform, and highly acceptable to children. It provides a simple and inexpensive means to measure functional exercise capacity in children, even of young age, and might be of value when conducting comparable studies.

Exercise Testing in Children and Adolescents with Chronic Fatigue Syndrome

The objective of this study was to evaluate exercise capacity in children and adolescents diagnosed with Chronic Fatigue Syndrome (CFS). We examined 20 patients (12 girls and 8 boys; mean age 14.9 +/- 3.7 years) diagnosed with CFS. Exercise capacity was measured using a maximal exercise test on a bicycle ergometer and an expired gas analysis system. Fatigue was assessed using a questionnaire and a daily activity diary was used to describe activities for three days. Z-scores were calculated using age- and sex-matched reference values. Z-scores in children and adolescents with CFS were - 0.33 +/- 1.0 (p = 0.17) for peak oxygen uptake, - 1.13 +/- 1.41 (p = 0.002) for relative peak oxygen uptake [ml/kg/min] and - 0.93 +/- 1.29 (p = 0.07) for maximal work load. Both heart rate and blood pressure at peak performance were significantly reduced compared to reference values. Fatigue levels were significantly positively associated with age and negatively with blood pressure at peak exercise (p < 0.05). In conclusion maximum exercise testing was feasible in young people with CFS. Maximal exercise capacity was only reduced in a minority of the patients and was related to current physical activity levels.

EFFECTS OF PHYSICAL EXERCISE ON QUALITY OF LIFE, EXERCISE CAPACITY AND PULMONARY FUNCTION IN CHILDREN WITH ASTHMA

To investigate the effects of regular submaximal exercise on quality of life, exercise capacity and pulmonary function in asthmatic children. Sixty-two children with mild-moderate asthma (mean age 10.4 (SD 2.1) years) were randomly allocated into exercise and control groups. The exercise group underwent a moderately intensive basketball training program for 8 weeks. A home respiratory exercise program was advised to both groups. Pediatric Asthma Quality of Life Questionnaire (PAQLQ) was used for the evaluation of activity limitation, symptoms and emotional functions. Exercise capacity was evaluated through the physical work capacity (PWC 170 test) on a cycle ergometer and 6-minute walk test. Spirometric tests were also performed and medication and symptom scores were recorded. Although PAQLQ scores improved in both groups, the improvement in the exercise group was significantly higher. The exercise group performed better in the PWC 170 and 6-minute walk tests, whereas no improvement was detected in the control group at the end of the trial. Medication scores improved in both groups, but symptom scores improved only in the exercise group. No significant changes were detected in pulmonary function in either group, except for peak expiratory flow values in the exercise group. Eight weeks of regular submaximal exercise has beneficial effects on quality of life and exercise capacity in children with asthma. Submaximal basketball training is an effective alternative exercise program for asthmatic children.

Impact of Cardiac Rehabilitation on the Exercise Function of Children With Serious Congenital Heart Disease

The exercise capacity of children with congenital heart disease (CHD) is often depressed. This depression is thought to be attributable to (1) residual hemodynamic defects and (2) deconditioning secondary to physical inactivity. We hypothesized that this latter component would be ameliorated by a formal cardiac rehabilitation program designed specifically for children. The objective of this study was to characterize the effect of a cardiac rehabilitation program on the exercise performance of children with CHD and to define the physiologic mechanisms that might account for any improvements that are observed. Nineteen patients with CHD who were referred for exercise testing and found to have a peak oxygen consumption (VO2) and/or peak work rate <80% of predicted were enrolled in the study. Sixteen patients (11 Fontan patients, 5 with other CHD) completed the program and had postrehabilitation exercise tests, results of which were compared with the prerehabilitation studies. Improvements were found in 15 of 16 patients. Peak VO2 rose from 26.4 +/- 9.1 to 30.7 +/- 9.2 mL/kg per min; peak work rate from 93 +/- 32 to 106 +/- 34 W, and the ventilatory anaerobic threshold from 14.2 +/- 4.8 to 17.4 +/- 4.5 mL/kg per min. The peak heart rate and peak respiratory exchange ratio did not change, suggesting that the improvements were not attributable merely to an increased effort. In contrast, the peak oxygen pulse rose significantly, from 7.6 +/- 2.8 to 9.7 +/- 4.1 mL/beat, an improvement that can be attributed only to an increase in stroke volume and/or oxygen extraction at peak exercise. No patient experienced rehabilitation-related complications. Cardiac rehabilitation can improve the exercise performance of children with CHD. This improvement is mediated by an increase in stroke volume and/or oxygen extraction during exercise. Routine use of formal cardiac rehabilitation may greatly reduce the morbidity of complex CHD.