Children and adults are different – this is a well-known fact. Experience, behavior, thinking, emotions and feelings, demands and needs – almost everything, in every single aspect of life is different in children and adult people. But the most important and obvious difference is biological. Body of a child and body of an adult are built by the same principle, but only in general. In fact, there are plenty of details in anatomical structure and functioning of the organism of a child that differ more or less comparing with the organism of an adult.
Physiological differences are at maximum when adult is compared to a newborn child. As a child grows, number of differences decreases and remaining differences tend to become less intensive. So, for example, adolescent human differs from an adult much less than six-year old child. Concerning physical activity during training session most important physiological differences between children and adults are differences in structure and functioning of cardiovascular and respiratory systems.
These differences are caused by immaturity of above mentioned systems of child’s organism and entirely different demands that are made to said systems by overall level of activity and metabolism of a child. Concerning structure and functioning of the respiratory system, children have lower tidal volume (because of smaller size of their lungs), and as a mechanism of compensation breathing frequency of children is higher than of adults.
Also children have smaller amount of dead space (regions that serve only for air transportation and take no part in air-blood gas exchange) in respiratory system, so they have larger amount of respiratory system actively taking part in blood oxygenation and carbon dioxide removal. Children who specially train themselves to increase their endurance change their type of breathing for more adult-like one – their breathe rate decreases and tidal volume increases as a result of training. Nevertheless, lungs of children are not yet developed fully, so rate of oxygen diffusion between blood and inhaled air through the lung tissue is lower.
Because of smaller size of heart and lungs and lower pumping capacity of the child’s heart volume of blood that passes through the lungs in a given period of time is lower. This, as well as lower diffusion capability, lowers the blood oxygenating capabilities of children lungs. But considering smaller size of a child’s body and lesser total circulating blood volume lungs function appropriately to satisfy body and brain demands for oxygen. Cardiovascular system of a child has other features that differ its function from CVS of an adult.
Volume of blood pumped through the heart during a single heart beat is much lower in children, and this causes higher heart rating despite smaller circulating blood volume and lower blood pressure because of smaller body size. During an exercise heart rate and heart’s pumping volume of a child increases, and blood pressure increases respectively as well as adult’s heart rate and blood pressure. Therefore it can be stated that cardiovascular systems of a child and of an adult respond to exercise in a similar way though resting and maximum cardiovascular parameters of a child will be higher than adult’s.
It also shows that brain coordination of heart and lungs function in children is performed adequately. Training programs for children should consider above mentioned physiological differences and provide lesser level of exercise stress because of these differences. Coach should bear in mind maximum exercise stress levels acceptable for the children of certain age and the fact that these levels are considerably lower than acceptable stress levels for adults.
Adequate training program can increase endurance and adapting capabilities of a child’s organism and could facilitate detection of potential or emerging troubles with respiratory and cardiovascular systems as well. But trainings with excessive stress can unbalance organism and disrupt its coordination capabilities, causing respiratory disorders or pathologies of blood circulation.
References:
- Houghton J. (2006). Understanding the biological differences between adults and children. Nurse Prescribing, 4(2), 54 – 59.
- Monroe, Lawrence J. “Psychological and physiological differences between good and poor sleepers.” Journal of Abnormal Psychology 72.3 (1967): 255.