The Stress Test

What is a stress test?

The stress test is a widely used procedure in sports medicine that consists of evaluating the body's response during exercise. A basic condition is the standardization of the procedure, that is, that the way it is carried out is always the same, in order to be able to compare the results between athletes and the individual evolution of any of them.

What is the purpose of the stress test?

The essential objectives of a stress test are the health diagnosis (confirming the absence of diseases, mainly cardiac) and the assessment of the athlete's functional capacity (the ability to exercise). After the procedure, data are obtained that allow medical advice on training, determining the recommended exercise intensities to achieve an improvement in sports performance.

Are there different types of stress tests?

Stress tests can be performed on a variety of equipment. The most used are the treadmill and the ergometric bicycle, one or the other being able to be used depending on the patient's situation or the sport practiced.

Different protocols can be used in the test procedure. The most recommended in athletes are those that involve progressive increases in workload, with a maximum duration of between ten and fifteen minutes, with direct analysis of oxygen consumption, and reaching maximum levels of effort.

What values ​​are analyzed during the stress test?

According to the recommendations of the Spanish Society of Cardiology (1), it is essential to perform an electrocardiogram before the test, and continuously monitor (view) the electrocardiogram during exercise and for at least 3-5 minutes during recovery.

In stress tests for athletes, direct gas analysis (measuring the oxygen consumed and the carbon dioxide eliminated) allows an exact determination of the maximum oxygen consumption and the precise detection of the aerobic and anaerobic thresholds. Indirect procedures (using mathematical formulas), especially in submaximal tests, are much less reliable.

How are training and stress testing related?

Oxygen consumption is the most appropriate determination to measure the capacity to perform aerobic exercise: a higher oxygen consumption is typical of well-trained athletes. The evolution of oxygen consumption is parallel to the improvement of sports performance, and allows the increase in physical capacity to be objectively measured.

The aerobic and anaerobic thresholds allow you to set the ideal intensity of aerobic (spinning) and anaerobic (series) training, to optimize performance, and recommend competition rhythms.

Is the stress test safe?

In an environment prepared to carry out stress tests, it is necessary to have the necessary equipment to respond to any emergency: emergency equipment and a defibrillator. The personnel performing the test must know the procedures to be applied in the event of cardiovascular complications.

These guidelines are essential, despite the fact that complications occur in 1 in 12.500 stress tests in healthy individuals