Youth Fitness: Differences between children and adults

Here are some interesting facts about the differences between children and adults concerning fitness and health.

There are numerous, important, physiological differences between children and adults concerning the functions of the cardiovascular, pulmonary, and muscular systems. During exercise children breathe in less air than adults. Children take more breathes per minute than adults but have a lower tidal volume. Most children begin to match adult ventilation rates at approximately 16-18 years of age.

Maximal and resting heart rates are much higher in children than adults. Children can have maximal heart rates as high as 220 beats per minute where adults do not usually go above 205 beats per minute. Stroke volume in children is also lower than adults. Lung diffusion capacity is also lower in children than adults. 

With blood pressure, children rarely go above a maximum systolic blood pressure of 160mm Hg. There is little to no change in diastolic blood pressure during exercise. Most children reach adult level blood pressure values after the adolescent growth spurt.

Active children may have raised levels of protein, hemoglobin and myoglobin in the urine following exercise due to reduced blood flow to the kidneys. Children have less lean body mass than adults and have lower levels of muscular strength and power output. Due to the less developed thermoregulatory system in children, they are at a higher risk than adults, for heat injuries like heat exhaustion and heat stroke. 

Muscular adaptations and hypertrophy in children are lower than adults because of their less developed nervous system, smaller muscle mass and lower hormone levels. This lasts until adolescence and puberty when the natural growth spurt occurs and levels of muscle building hormones such as testosterone, growth hormone and IGF-1 become higher.

References:

Fahey, Thomas. Youth Fitness Trainer, 3rd Ed. Carpinteria: International Sports Sciences Association, 2015. Print.

Eric Dempsey

MS, TFW Level 2 Coach

Dempseys Resolution Fitness