Edited by Dr. Francesco Grazzina
The cardiopulmonary exercise test is now widely used as a method for evaluating the adaptation to exercise both in healthy subjects who are dedicated to sporting activity and in subjects suffering from cardiopulmonary diseases.
For these reasons, this test represents an irreplaceable method: to date it is currently used to determine the degree of training, disability or invalidity, as well as the effectiveness of a training or rehabilitation program.
For a correct execution of a cardiopulmonary exercise test, an in-depth knowledge of the physiological mechanisms underlying the adaptation to effort, the protocols and measures necessary to calculate and evaluate the degree of efficiency of gas exchanges and adaptations is required. cardiovascular, and not least of the interpretative principles that are not always easy to apply due to the numerous variables involved.
The objective of these tests is to measure the adaptation to effort, analyzing the responses: physiological, ventilatory, cardiovascular and metabolic, in order to identify any factors limiting performance.
The correct execution of a cardiopulmonary test requires to accurately quantify the stress in terms of external work (ergometry) and to measure, as accurately as possible, the energy expenditure.
In this context, the quantification of the maximum aerobic power, proportional to the V "O2max, assumes particular importance since it represents the fundamental limiting factor for sports specialties that require a preponderant production of energy through the aerobic mechanism, and in this sense the measurement of the V "O2max represents an irreplaceable selective index.
The V "O2max is usually measured or estimated with maximal tests or on a cycle ergometer or treadmill in the laboratory, or it is estimated by means of field tests.
The advantages of the tests carried out in the laboratory lie in the fact that all physiological parameters can be monitored and that they have high precision; field tests, on the other hand, allow a large number of subjects to be carried out in a short period of time.
The biggest problem with maximal laboratory tests is that they require expensive equipment, qualified personnel in the execution and analysis of the numerous data obtained. Furthermore, the effort required to obtain the V "O2max requires motivation and cooperation on the part of the subjects.
Field tests, on the other hand, do not require expensive equipment like laboratory ones, but present the same problems related to having to make a very intense effort on the part of the subject. In addition, they often lead to an excess of motivation and competition. They are limited by the ability to collect a poor set of physiological variables. In general, they are simply made up of evaluations of subjects performing high intensity field tests and based on the maximum length of a course in a standard time.
The complexity of the physiological and methodological aspects connected to the evaluation of the V "O2max led, consequently, to the proposal of various methods to estimate and measure the V" O2max - both in the laboratory and in the field - able to simplify the procedure and based on the measurement of the heart rhythm, on the respiratory exchange ratio measured during a submaximal exercise, on a minimum time for standard performance, or on the maximum length of a path in a standard time. These types of tests have both advantages and of course disadvantages: the advantages lie, for example, in the possibility of eliminating motivation as a determining factor in carrying out the test, and last but not least, in the fact that they can also be performed by sedentary or elderly individuals, without the inconvenience and potential risks associated with a maximum effort
In general, indirect tests, whether maximal or submaximal, for the evaluation of maximum oxygen consumption, are characterized by a correlation coefficient between values relating to the same subject, which for some authors may vary depending on the test from 0.4 to 0.96. .
