ABSTRACT
The most important functions of the cardiopulmonary system during exercise are to deliver oxygen to the exercising muscles and to remove the metabolically produced carbon dioxide from those muscles. During the development of youth cyclists their cardiopulmonary system will grow. Cardiac output is closely regulated to the metabolic demands of the body. Heart rate has been found to increase almost linearly during progressive exercise up to maximal intensity, with no difference between the profiles of the response in boys and girls. A high Maximal oxygen uptake is a prerequisite for elite endurance athletes in sports such as cycling. The ventilatory threshold concept provides the physiologist or coach with information concerning the transition from oxidative metabolism to anaerobic glycolysis during progressive exercise. Minute ventilation represents the total output of the pulmonary system and is the product of tidal volume and breathing frequency. It has been found that ventilatory efficiency improves with age during childhood.
