Air conditioning in the studio is of crucial importance. This is because children produce more heat per kg body weight than adults, but their thermo-regulatory system is not as good. This is partly because they sweat less. Children also tend to have higher skin temperatures, which hinder the flow of heat from body core to the periphery. However, children have a proportionately greater skin surface area the smaller they are. A young adult weighing 64kg will have a surface area of about 1.80 square metres; An eight year old weighing 25kg will have a skin area of 0.95 square metres, i.e. 36 per cent more surface area per unit of weight. This helps to correct thermal imbalances, but can be a disadvantage when running in direct sun (or swimming in cold water) - with the possibility of a faster rate of overheating (or of overcooling). To this end, water must be provided for every child.
It's also important to be aware that children breathe faster than adults, reaching 60 breaths/minute compared to 40/minute in adults doing equivalent exercise. Compared to adults, children need to breathe more air to get the same amount of oxygen, i.e. their 'ventilatory equivalent for oxygen' (the number of litres of air to gain one litre of oxygen) is higher. This is wasteful of energy and body water (in the breath). Occasionally it may lead to "Hypocapnic Tetany" (HT), whereby very high respiratory rates may lead to an excess blow-off of carbon dioxide, which increases the blood pH or alkalinity, affecting blood calcium and nerve function, and leading to a degree of spasm in feet and hands, and numbness around the mouth. HT can occur in the heat, as in training and competition in summer, but increasing numbers of cases are being reported outdoors in winter - for example from junior rugby matches. The condition is not at all serious but the young victim may panic, and alarm onlookers. A simple cure is to get the child to sit down in a quiet place and breathe slowly for a few minutes, so raising the carbon dioxide and normalising the pH levels. To this end, a Heart Rate Monitor must be provided for very child.
Younger children incur less of an oxygen deficit at the beginning of exercise - i.e. they get their 'second wind' quicker. As their deficit is less, so they also recover quicker. They also have higher 'anaerobic thresholds' than adults, and in this, oddly enough, they resemble trained adult endurance runners. Children's muscle tends to use more fat as fuel than glycogen or glucose. However, for the same amount of energy, approximately 10 per cent more oxygen is needed, if fat is the substrate compared to glucose/glycogen, it is a less efficient fuel. Children also tend to utilise glycogen or glucose more slowly the younger they are. Thus the younger the child, the less efficient aerobically, they are made worse by relative biomechanical inefficiencies, in that the lengths of younger children's limbs are not completely in 'kinetic balance' with their muscles. They also have proportionately less body mass in muscle - some 28 per cent in young children, compared to 35-40 per cent or more in the late teens. On the anaerobic side, the younger the children, from about 8 to 16, the lower the proportion of anaerobic energy they can generate, and the lower the levels of lactic acid in blood. Thus, the younger the child, the less they have an built-in fatigue mechanism, and a lack in understanding RPE. Children's perception of the severity of exercise is less the younger they are. An important physiological function of fatigue is to prevent muscle damage through excessive effort. Young children, without the same early-warning fatigue system as their elders can easily be pushed in team or individual coaching sessions to the point where they are overheated, dehydrated and distressed.
Instructor requirements (in the UK):
Valid Spinning® Certification.
Youth specific qualification e.g. CYQ Trained (Central YMCA Qualification) e.g CYQ Level 2 Exercise for Children, which provides you with the certificate required to deliver exercise sessions for ages of 5 to 16 year olds.
Anyone teaching children, has to by law complete a CRB Check (Criminal Records Bureau).
Parental consent is required along with a completed PAR-Q (Physical Activity Readiness Questionnaire).
If more than 10 per class, a 2nd staff member is required to assist.
Yours in Sport,
International Spinning® Master Instructor (UK)