Title: The developmental changes in physiological cost of locomotion efforts in overweight boys
- Marcin Maciejczyk, Jadwiga Szymura, Jerzy Cempla, Joanna Gradek
- Original articles
- Pediatric Endocrinology, Diabetes and Metabolism
- Start page:
- Final page:
- oxygen intake, physiological cost, obesity, boys, exercise
Introduction: In obese children the aerobic capacity (maximal oxygen intake) is lower than in non-obese children,
but lower ability to perform long-term efforts can also result from higher physiological cost (in comparison to
normal weight children) during locomotion efforts.
Aim of the study was to determine developmental changes in physiological cost of walks in boys with excessive
level of body fat (F%) during puberty.
Material and methods: The study was conducted on 11 boys with excessive level of body fat (%F=26.82±2.89 %
- GROUP O) and 14 with normal level of body fat (%F=12.51±2.35% - GROUP P). The boys performed the graded
test and a few days later two submaximal walks (6 min each with a 4 min pause for rest between walks) on mechanical
treadmill with different speed (3.6 km×h-1 and 4.8 km×h-1) every two years (three series) beginning at the age
about 10 years and finishing at the age of 13-14 years.
Results: The level of pulmonary ventilation (VE) and tidal volume (TV) were significantly higher in overweight boys,
but breathing frequency (BF) was similar in both groups. With age, the economy of breathing was improved in both groups: pulmonary ventilation and tidal volume were increasing but BF was decreasing. The work intensity during
walking, expressed as %VO2max and %HRmax, was higher in boys with excessive level of body fat and decreased with
age. Total values of VO2 (l×min-1) were higher in the group of overweight boys, but relatively to body mass the values
of VO2 were significantly lower in this group and with age the difference between groups was constant.
Conclusions: The physiological cost of walking was higher in boys with excessive level of body fat in each test in
comparison with non-obese boys. The difference between groups in level of physiological parameters increased
with speed of walking. The physiological cost of walking decreased with age in both groups.