Over the past few years, schools, public parks and recreation areas, agencies, and independent fitness centers have attempted to implement recommendations from both the Surgeon General's Report for 1996 and the 1997 Guidelines for School and Community Programs on the Promotion of Physical Activity throughout life some young people. Among these proposals is a recommendation that schools, community programs, and the fitness industry should collaborate in providing a safe environment, role models, competence leadership and related activities for children and adolescents. In addition, parents are encouraged to plan and participate in physical activity with their children. However, if you were playing with a child, you would be worried if you noticed that your child seemed to breathe harder and have a higher heart rate, but did not sweat as much as you?
Respiratory system
The primary role of the respiratory system is to provide oxygen and eliminate carbon dioxide from muscle cells. The amount of air exchanged per minute is called minute ventilation and is the product of the number of breaths (frequency) multiplied by the volume of each breath (tidal volume). Children and adolescents exhibit a higher frequency and lower tidal volume than adults, at all intensities. (1,2) Since fast breathing is easily noticed, it can upset a benevolent adult. Higher frequency and lower tidal volume is normal and does not require an alarm. In fact, if you had to make adjustments to body weight, children and teenagers breathe more air per minute per kilogram than adults, with the same maximum maximum intensity. These differences are compensated for by a smaller dead space. Dead space is the volume of air trapped in the building part of the lungs, which is not available for exchange on the alveoli. The alveoli provide a vital surface for gas exchange between the lungs and blood. Alveolar tissue has the largest blood supply to any organ in the body. (3) It is like a piece of water in the pipes of your house. Less dead space leads to most of the air inhaled by the child, actually entering the alveoli. (4)
Often, a comparison is made between the amount of air that is processed (minute ventilation) and the amount of oxygen used (VO2) for aerobic energy production. This comparison is called the ventilation equivalent. Children and adolescents have higher ventilatory equivalents than adults, and the difference if they are inversely related to the age of the child. (1,2) Thus, the younger the child, the more air they must breathe. Because of the higher ventilation equivalent observed in children and adolescents, it is generally considered insufficient, the boy must spend extra energy to support breathing during the exercise. (2) However, neither this deficiency nor any other differences previously described for the respiratory system indicate physical activity in children or adolescents.
The cardiovascular system
The cardiovascular system is primarily a transport system consisting of the heart, blood and blood vessels. Its task is to transport oxygen, nutrients in the form of carbohydrates, fat, protein and hormones, such as insulin and adrenaline, to reach muscle cells. Carbon dioxide, heat, and other by-products of energy metabolism are removed from the cell level by the cardiovascular system. (5) Oxygen delivery depends on the amount of blood pumped every minute from the heart, which is called cardiac output (cardiac output = stroke volume: the amount of blood pumped into the ventricular x heart rate per minute) and the amount of oxygen discharged from the red blood cells difference in oxygen. Children and adolescents demonstrate a lower volume and higher heart rate than adults, with all the intensity of exercise. Since the volume of stroke is related to the size of the ventricle, a higher heart rate is probably an attempt to compensate for the smaller size of the ventricles in children and adolescents.
It is normal for a child to have a greater heart rate than a parent if they perform the same exercises together. The maximum heart rate is higher in children and adolescents than in adults, but does not change over 7 years with age. This allows you to estimate the maximum heart rate using established ratios, such as 220-year inaccurate for children and adolescents, until the late teens. It also means that if there are no signs of stress or coercion, there is no reason to worry about the heart rate values exceeding 200 beats / min. Healthy people should be able to train for a few minutes at maximum heart rate. In fact, since the VO2 max (the greatest amount of oxygen that can be inhaled during aerobic exercise) depends on the body weight of the person, the VO2 max values are as high or higher than in most adults. Heart rate will recover faster in children and adolescents than in adults. (2) Controlling the temperature of the cardiovascular system is crucial for the participant in the workout and is more difficult for children and adolescents. Their ratio of surface area to mass is greater than that of adults, which allows for greater heat transfer through convection and radiation.
Convection is associated with construction, which is the ability to gain or lose heat by exchanging solid, liquid or gaseous from one molecule. Since our bodies are usually warmer than the environment, the pure exchange of radiant heat energy is carried through the air to solid, colder objects in the environment. It does not require body contact with a warm object. Radiation is how the sun warms the earth, or in other words, a person can stay warm by absorbing radiant heat from the sun or indirect sunlight reflected from snow, sand or water. Children do not sweat as much during exercise as adults. The number of sweat glands is the same, but the activation of the sweat glands occurs at a higher temperature; less sweat is produced from each gland, and the rate of sweat per unit surface area is lower. Children and adolescents also have a smaller amount of plasma than adults, from which fluids are drawn to sweat. (6) In a neutral climate, the temperature-regulating ability of children and adolescents is comparable to the temperature of adults. However, children and teens have a shorter exercise time at extreme temperatures. (6) They can acclimatize before the heat, but they take longer than adults. The tendency is to try to do too much too soon. It is recommended to tolerate or recommend strenuous activity when high temperatures and humidity are high, and make sure that a lot of fluid is swallowed before, during and after exercise. Thirst is not an accurate guide to fluid needs.
Well, now you know the answer to the question in the first paragraph. It is perfectly normal for a child or teenager to complicate breathing and have a higher heart rate than an adult, however, if the heat or humidity is excessive, it may be reasonable to postpone the exercise, the lower the intensity. Do not forget to moisten before and after. Good luck!
1. Bar-Or. Children's sports medicine for a trainee: from physiological principles to clinical applications. New York: Springer-Verlag, 1983; pp 1-65
2. Rowland, T. W Exercise Physiology Exercise. Champaign, Illinois: Human Kinetics, 1996
3. McArdle, William D., Katch, Frank, I., Katch, Victor, L., Physiology Physiology, 2nd edition, pg. 192.
4. Bar-Or. Children's sports medicine for a trainee: from physiological principles to clinical applications. New York: Springer-Verlag, 1983; pp 1-65
5. Plowman, SA and DL Smith. Physiology of Exercise for Health, Fitness and Performance, Boston: Allyn
6. Bar-Or, O. children and exercise in a warm and cold environment. In Advances in Pediatric Sport Sciences. Volume I: Biological issues. RA Boileau (ed.), Champaign, Il: Human Kinetics Publishers, 1984; p. 117-0130
