Gas exchange measurement systems are complex and require specialized facilities and expertise. As a result, access to these measurements remains limited, particularly in the field of sports performance. The aim of this validation study was to compare measurements obtained with a reference device and a new portable system.

Exercise gas exchange measurement is the gold-standard method for assessing maximal and submaximal aerobic performance. The measured variables are essential for the objective evaluation of exercise performance.

These parameters are used to assess an individual's performance level, determine training zones, and thereby personalize training programs. Their accuracy is therefore of critical importance.

However, the assessment of ventilatory parameters is complex, as it relies on measurements of airflow (using pneumotachographs) and gas concentrations in inspired and expired air (using O₂- and CO₂-sensitive sensors). The physical properties and composition of air differ between inspiration and expiration. In particular, the saturation of expired air with water vapor-which does not behave as an ideal gas-introduces significant challenges and can reduce the reliability of current measurement systems.

The accumulation of these individual sources of measurement error ultimately determines the overall quality and accuracy of a commercial gas exchange analysis system.

Nevertheless, athletes and coaches require regular access to these measurements in order to prescribe appropriate training intensities and evaluate training effectiveness. A recent comparative study of several commercially available portable systems highlighted substantial variability in both measurement accuracy and overall performance among existing devices. Consequently, the availability of a simple, accessible, and, above all, more accurate measurement system would represent a significant advance for the sports performance community.

Inclusion Criteria:

• Male or female adults (aged ≥ 18 years).
• Individuals affiliated with, or benefiting from, a health insurance or social security scheme.
• Individuals capable of understanding and signing an informed consent form.
• Individuals fluent in French.

Exclusion Criteria:

• Current tobacco smoking.
• Any cardiovascular, respiratory, or musculoskeletal condition that could impair the ability to perform a maximal exercise test.
• Individuals unwilling or unable to provide written informed consent.
• Individuals with hierarchical, family, or close personal relationships with the principal investigator.

Healthy people from sports team