The sports medical examination is a non-invasive procedure that provides diagnostic information about cardiovascular functioning and evaluates the individual’s capacity to perform dynamic exercise.
Therefore, we can say that stress tests have several objectives:
- To assess the individual capacity to perform dynamic exercise.
- To assess the response of different systems to exercise (cardiovascular, respiratory, etc.).
- Obtain data to improve performance
- Obtain data to prescribe individualized exercise.
- Assess the health status of the athlete and detect known or unknown anomalies that may limit or contraindicate the practice of sports.
- Assess the behavior of certain pathologies in relation to exercise (hypertension, diabetes, etc.).
- Diagnose, prognosticate and assess pathologies directly linked to exertion such as exercise-induced asthma.
In addition, they should always be done:
- In asymptomatic athletes over 35 years of age with two or more risk factors, as an assessment of fitness for sports practice.
- In asymptomatic athletes under 35 years of age with a family history of sudden unexplained exercise-related death in young first-degree relatives.
What does the sports medical examination consist of?
In the sports medical examination, in addition to a personal and family medical history, a sports medical history must be taken. A resting electrocardiogram, anthropometry, spirometry and a monitored stress test will be performed. The stress test can also be carried out with a gas analyzer, in which case we will speak of an ergospirometry.
Some basic preconditions must be met for the stress test to be performed:
- The patient must be informed about the methodology to be followed and the risks involved.
- Those patients who are taking medication will have to assess the possibility of suspending it prior to the test since it could influence the result.
- They will not be able to eat or take caffeine in the 3 hours prior to the test, but this cannot be done if there is a prolonged fasting. If you are a smoker, it is recommended not to smoke for 3 hours prior to the test.
- It is recommended to avoid intense physical activity or unusual exercise in the 12 hours prior to the test.
- The stress test should be done with sports clothing and footwear.
- The room where the stress test is carried out must have constant environmental conditions that favor the dispersion of perspiration and the heat caused by exercise, with a temperature between 18 and 22ºC and a relative humidity of 40-60%. In this way, heat, humidity and their consequences will not affect the development of the test, the responses or the parameters analyzed.
How often should these examinations be performed?
These examinations should be done annually and at the beginning of the season to have objective values that help to prepare a training program tailored to each athlete.
When we talk about athletes of a higher level or professionals, the ideal is to carry out three, at the beginning of the season, in the middle of the season and at the end.
What are the benefits and advantages of this recognition?
This type of examinations, not only will be able to rule out cardiac pathology, possible exercise-induced asthma, AHT in exercise that will lead us to think about a possible hypertension later, but it will give us objective data on the physical fitness of the athlete and is, or should be, a fundamental working tool for coaches when adjusting training and seasonal objectives.
Stress test in the evaluation of the state of fitness
VO2 obtained directly or indirectly, is the most referenced indicator to assess fitness, both in sedentary and in athletes, although the maximum load can also be used for this purpose.
- Training planning
The fundamental parameters provided by the stress test are two: maximum heart rate and maximum load. In addition, several studies have found a connection between VO2 percentage and HRmax, which makes it possible to express work intensity according to both parameters.
Lactate concentration (mmol/l) and VO2 are other parameters that can be obtained in the stress test that help to characterize the various types of training.
From the data obtained and the estimation of the anaerobic threshold, the different work intensities for the different functional areas can be proposed.
- Control of the training load
The HRmax obtained in the stress test serves as a support point for training load quantification models. The most widely used has been that of Bannister et al. based on the so-called training impulse units, but Foster et al. later modified them and established a simpler model based on the three-phase model of Skinner and Mclellan, which delimits three work zones.
Zone I would be below the ventilatory threshold VT1 (assimilable to 85% FCmax) and would be multiplied by three each minute in this zone.
- Monitoring the evolution of the training process
The stress test is a reliable method for objectifying the evolution of the state of fitness, which makes it possible to evaluate the effects of planned training.
- Stress test for exercise prescription
We define exercise prescription as the process by which a person is recommended a regimen of physical activity in a systematic and individualized manner. The fundamental objectives of physical exercise prescription include improving physical fitness, improving health (health promotion, disease prevention and treatment) and improving safety in the practice of physical exercise.
We understand physical fitness as the ability to perform the usual activities of daily living without fatigue and in such a way that one can enjoy active leisure activities and cope with unforeseen emergencies without excessive fatigue. Adequate physical fitness helps to avoid diseases caused by sedentary lifestyles.
The most important components of physical fitness are strength, strength-endurance, adequate body composition, balance, coordination and cardiorespiratory endurance. It is the latter that can be assessed with the stress test.
The results of the stress test are the basis for the prescription of physical exercise on an individualized basis for the improvement of sports performance, but also for the indication of physical exercise to improve physical condition in the general population and for the prevention and treatment of a large number of diseases.
- Stress test for exercise prescription in competitive sport
The aerobic profile improvement sought in many sports will be based on aerobic power (VO2max) and aerobic-anaerobic transition thresholds 1 and 2, either ventilatory (VT1/VT2) or lactate (LT1/LT2) at the time of study and control assessments throughout the sporting season(s).
The data at maximum level and in the aerobic-anaerobic transition obtained from the medical tests will be used to plan the loads and training by the physical trainers of each sport specialty.