Lung, not only heart

It is well known that physical exercise requires the coordinated function of the heart, lungs and peripheral and pulmonary circulation to support the increased demands of contracting muscles. This evidence is well represented by the so-called Wasserman’s gears representing the functional interdependence of the physiological components of the system and the mechanisms for coupling internal (i.e. cellular) and external (i.e. pulmonary) respiration [1]. The working muscles need a huge increase in oxygen utilization, which is achieved by increasing the extraction of oxygen from blood perfusing muscles and by increasing cardiac output, pulmonary circulation and ventilation. The lung has therefore a crucial role in the performance of exercise but quite often this fact is neglected, especially in athletes (with exception of those suffering from exercise-induced bronchospasm) and in healthy subjects. Sometimes it seems that the role of the lung in exercise is considered only in subjects with respiratory limitations. Respiration is generally assumed to be the least important exercise-limiting factor because ventilation seems to have enough reserve. Indeed, the pulmonary system can be a limiting factor during exercise also in healthy asymptomatic subjects and not only in individuals suffering from cardiovascular and respiratory diseases. In particular, expiratory flow limitation and diaphragm fatigue can be detrimental to exercise performance in some endurance athletes [2]. Despite this fact, ventilatory evaluation has never been looked as an important tool for performance evaluation. By inserting in Pub Med the words “Exercise, Athletes, Heart” 1,188 papers are displayed in the last ten years; only 141 when “Heart” is replaced with “Lung”. Furthermore, with regard to the exercise in athletes, the attention is almost always focused on the lung as gas exchanger rather than on the ventilatory parameters. Actually, the lung is composed of two functionally distinct compartments, equally important: the conducting region and the gas-exchange region, but this is the zone regarded with more interest when it comes to lung and exercise. What is known about exercise and respiratory function? Some information is available about the influence of