ABSTRACT
The method of removing the confounding effect of body mass on peak oxygen uptake simply by dividing the measured values by body mass has been questioned. The aim of the study was to find an expression of body mass for compensating for differences in body mass so as to achieve the best correlation to running performance. In a cross-sectional study, design peak oxygen uptake (VO2peak) was measured in 107 boys in the age range 8-17 years and 88 girls in the age range 8-16 years. The present study indicates that VO2peak do not increase in proportion to body mass during running, rather that VO2peak is inversely related to body mass. When using allometric regression standards with the sexes separated in gender groups, there was a tendency that boys achieved scaling factors closer to unity than did the girls. The increase in subcutaneous fat in the girls throughout the pubertal years is the most likely reason why body mass increased proportionally more than VO2peak in girls. The present study indicates that VO2peak when expressed as milliliters per kilogram per minute (ml kg(-1) min(-1)) is a poor denominator for VO2peak as a function of running performance in children and adolescents.
Subject(s)
Body Constitution/physiology , Oxygen Consumption/physiology , Physical Endurance/physiology , Running/physiology , Adolescent/physiology , Age Factors , Aging/physiology , Child , Female , Humans , Male , Predictive Value of Tests , Regression Analysis , Sensitivity and Specificity , Sex Factors , Task Performance and AnalysisABSTRACT
The aim of the present study was to evaluate different aspects of a device designed to monitor physical activity. Measurements of different axes and placement of the monitor were tested using a treadmill with ranging increments in incline or speed. The monitor was also used to assess the level of physical activity among children and adolescents with congenital heart disease and in healthy controls at the same age. The results indicate that the monitor is a valid and reproducible instrument for measurements of physical activity. The study revealed that the level of activity was higher for healthy boys than healthy girls (p<0.0001). Boys with congenital heart disease also displayed higher values compared to girls with congenital heart disease, although the difference was not significant (p=0.067). Healthy boys revealed a significantly higher level of activity than did boys with congenital heart disease (p=0.003), but no such difference was found in girls (p=0.757). Nor were any differences found between younger and older individuals among patients with congenital heart disease. Young healthy controls, however, showed significantly higher levels of activity than their older counterparts. There were differences in activity monitored during the week, with lower activity in the weekends, but the activity on the same day in different weeks seemed stable. Neither were there any differences between measurements over whole weeks. The results indicate that the Computer Science & Application monitor is a valid instrument for assessing physical activity. The monitor may also be used, therefore, to validate the levels of physical activity level in children with congenital heart disease after medical and surgical treatment.
Subject(s)
Heart Defects, Congenital/physiopathology , Monitoring, Ambulatory/instrumentation , Physical Exertion/physiology , Adolescent , Analysis of Variance , Case-Control Studies , Child , Female , Humans , Linear Models , Male , Oxygen Consumption , Sex FactorsABSTRACT
In order to test the effect of systematic supervised physical training, we divided a total of 129 children and adolescents with congenital heart disease into a group undergoing intervention and a control group. All patients underwent exercise tests, measurements of physical activity, and a survey of psychosocial factors. An improvement in uptake of peak level of oxygen was observed after intervention. There was also an improvement in physical activity in both groups measured by a monitor, although this was significant only in those with intervention. The psychosocial scales measured by the Child Behavior Checklist showed a decrease in internalizing scores for those subjected to intervention. This was decreased due to decreased withdrawal and somatic complaints. In conclusion, we recommend systematic supervised training, including testing of routine follow-ups, in patients with congenital heart disease.
