Endurance In Children Research Articles

The extent to which breakfast covers the morning energy expenditure of adolescents with varying levels of physical activity.

Energy intake at breakfast affects the performance of creativity tests, memory recall and voluntary physical endurance in children before lunch, and food craving during the whole day. To assess the adequacy of breakfast energy supply (BES) and energy expenditure (EE) in adolescents during a schoolday without or with 2 h of physical education lesson (PEL) in the morning. Sixty adolescents (four groups of 14-16 boys and girls aged 12-16 y) participated in a cross-sectional study. Activity patterns and EE were determined by whole-body calorimetry during 36 h and in free-living conditions during 5 days using both a diary and the validated heart rate recording method. BES was determined by weighing individual foods. The pyloric energy flow was assessed using a model of fractional stomach emptying. BES averaged 24.9% (s.d.=6.1) of daily EE in the four groups of subjects. It covered the mean morning EE on a schoolday without PEL, but not in a schoolday with 2 h of PEL in any group. When PEL took place from 8-10 am the cumulative EE exceeded the cumulative pyloric energy flow after 105-150 min, that is during the PEL session, and the energy deficit increased until lunch. With a light breakfast (BES-1 s.d.) energy deficiency happened after 90 min. The results stress the need for a heavy breakfast for children and adolescents on the days with PEL in the morning, and a carbohydrate rich snack at 10 am to improve attention, memory and willing participation in physical activities.

Dose-dependent effect of individualized respiratory muscle training in children with Duchenne muscular dystrophy

The aim of this study was to evaluate the effects of low intensity, home inspiratory muscle training on respiratory muscle endurance in children with Duchenne muscular dystrophy, using a double-blind protocol. The originality aspect of this study is the use of a reproducible method of endurance and of the same method for evaluation and training. We studied eight trained children (mean age 14.7±4.5 years) and eight control children (mean age, 12.6±1.8 years). For 6 weeks, children breathed twice a day for 10 min through a valve with either 30% (training group) or less than 5% (control group) of their maximum inspiratory pressure ( P imax). The results showed (1) a 46% improvement in the time limit after training in the training group and no change in the control group and (2) a significant correlation between the total time of respiratory muscle training and the percentage of endurance improvement in the training group. We conclude that specific training improves respiratory muscle endurance in Duchenne muscular dystrophy and the effectiveness of training appears to be dependent on the quantity of training.

A standardized method for the evaluation of respiratory muscle endurance in patients with Duchenne muscular dystrophy.

The aim of the study was to develop a standardized method using controlled breathing to quantify respiratory muscle endurance in children with Duchenne muscular dystrophy (DMD) and to test its reproducibility. In 10 DMD patients, all between 10 and 14 years (mean age, 11.5 +/- 1.5 years), except for two patients of 20 and 22 years, and 10 healthy children (mean age, 12 +/- 1 years), we measured the maximal time (Tlim) that a threshold load fixed at 35% of the individual maximal inspiratory pressure (Pimax) could be tolerated. We asked the children to maintain their rest breathing pattern until exhaustion using visual feedback and an auditory signal. The mean Tlim in the DMD children was 4.45 +/- 1.45 min and values were reproducible. All healthy children were able to obtain Tlim values greater than 30 min. The respiratory muscles of DMD children are more susceptible to fatigue than those of healthy subjects. This method should be satisfactory for estimating the effect of treatment and for the specific training of respiratory muscles in DMD patients without significant learning disability.

Development of validated disease activity and damage indices for the juvenile idiopathic inflammatory myopathies. II. The Childhood Myositis Assessment Scale (CMAS): a quantitative tool for the evaluation of muscle function. The Juvenile Dermatomyositis Disease Activity Collaborative Study Group.

To develop, validate, and determine the measurement characteristics of a quantitative tool for assessing the severity of muscle involvement in children with idiopathic inflammatory myopathies. The Childhood Myositis Assessment Scale (CMAS) was developed from 2 existing observational functional assessment tools to assess muscle function in the areas of strength and endurance across a wide range of ability and ages. The 14 ordinal items included were chosen to assess primarily axial and proximal muscle groups and are ranked with standard performance and scoring methods. Following the development of the CMAS, a training video and written instructions were developed and reviewed by the physicians participating in this study. Subsequently, utilizing a randomized block design, 12 physicians independently scored 10 children (9 with dermatomyositis, 1 with polymyositis; ages 4-15 years) twice in one day (morning and afternoon) on the CMAS. A pediatric physical therapist performed quantitative manual muscle strength testing (MMT) twice on each child (morning and afternoon), including the neck, trunk, and proximal and distal extremity muscle groups. The CMAS has a potential range of 0-51, with higher scores indicating greater muscle strength and endurance. The observed mean for the 10 patients was 36.4 (median 44, SD 14.1, observed range 5-51). The total score for the CMAS correlated with the physician's global assessment (by visual analog scale) of disease activity, the MMT score, serum creatine kinase level, and the Juvenile Arthritis Functional Assessment Report score. The score on the CMAS was not correlated with patient age. Interrater reliability (Kendall's coefficient of concordance) ranged from 0.77 to 1.0 for individual items (all P < 0.001), and overall, it was 0.95 (P < 0.001). Intrarater reliability for the individual physicians was measured by correlation of the CMAS scores for each patient on 2 separate evaluations and ranged from 0.97 to 0.99, with an overall correlation for all physicians of 0.98 (all P < 0.001). The CMAS demonstrated an acceptable range of observed scores, excellent convergent validity, and excellent inter- and intrarater reliability. The CMAS is validated to quantitatively assess muscle function in the areas of strength and endurance in children with idiopathic inflammatory myopathies. It can be used in routine clinical care as well as therapeutic trials.

Standardized evaluation of respiratory muscle endurance in children with progressive muscular dystrophy

Standardized evaluation of respiratory muscle endurance in children with progressive muscular dystrophy

Does inhalation injury limit exercise endurance in children convalescing from thermal injury?

The cardiopulmonary performance levels in children who are convalescing from thermal injury are unknown. This investigation was designed to evaluate cardiopulmonary function in children with and without inhalation injury. Forty children with a mean time since burn injury of 2.6 +/- 1.9 years and a mean burn size of 44% +/- 22% total body surface area were selected for the study and divided into two groups: inhalation injury (group 1) and non-inhalation injury (group 2). Pulmonary function studies and cardiopulmonary stress testing were completed on all patients. Both groups reached the same endurance level on the treadmill; however, patients in group 1 did so with an increased expired volume, respiratory rate, and ratio of dead space ventilation to total ventilation which indicated that there were greater demands on the respiratory system. Spirometry and lung volumes at rest showed that 64% of patients in group 1 had abnormal lung function compared with only 27% of patients in group 2.

A comparison of the maximal endurance of normal children and patients with congenital cardiac disease

A technique to measure maximal endurance in children is described, and the results of its application to normal children and to those with congenital cardiac lesions are recorded. The children with heart disease were unable to achieve pulse rates as high as could the normal ones, and had considerably less endurance. The maximal endurance score of a child with cardiac disease tended to reflect his functional status as indicated by cardiac catheterization studies.