The goal of this cross-over study is to evaluate the physiological response to exercise and body composition according to training status in participants with a wide spectrum of fitness states. The main questions it aims to answer are:

• Which are the physiological differences across participants with different training status?
• Which are the body composition differences across participants with different training status?

To satisfy the objective of the project, participants will perform an incremental test until volitional exhaustion. During this test, respiratory gases will be measured via a gas analyser as well as the cardiac response via an electrocardiogram. The same participants will have their body composition measured by dual X-ray densitometry (DXA).

Inclusion Criteria:

• Be in enough physical fitness to perform the incremental test to volitional exhaustion.

Exclusion Criteria:

• Present any health condition preventing to perform the incremental exercise test until volitional exhaustion.

In accordance with the law 15/1999 on the protection of personal data, the personal data required are those necessary for scientific purposes, for possible studies that may be carried out. In none of these possible studies will your name appear and your identity will not be revealed to any person except to fulfil the purposes of the study, and in the event of a medical emergency or legal requirement. Any personally identifiable information will be retained and processed under secure conditions for the purpose of determining the results of possible studies. The results of these studies may be communicated to health authorities and the scientific community through conferences and/or publications.