Assessing the Validity and Reliability of the PNOE¯ for Measuring Cardiometabolic Outcomes During Walking Exercise

Area of Science:

• Cardiorespiratory physiology
• Exercise science
• Biomedical engineering

Background:

• Accurate measurement of cardiometabolic outcomes, including gaseous exchange and energy expenditure, is essential for health assessments.
• The PNOE system's validity and reliability for these measurements during exercise require thorough evaluation.

Purpose of the Study:

• To compare the PNOE system's accuracy against the COSMED K5 system for measuring cardiometabolic outcomes.
• To assess the validity and reliability of the PNOE system in healthy individuals during treadmill exercise.

Main Methods:

• Twenty-one healthy subjects performed a graded treadmill exercise protocol.
• Cardiometabolic parameters including oxygen uptake (VO2), carbon dioxide production (VCO2), and energy expenditure (EE) were measured using PNOE and COSMED K5 systems.
• Validity was assessed using Bland-Altman plots and intraclass correlation coefficients (ICCs); reliability was tested via test-retest.

Main Results:

• Intraclass correlation coefficients indicated good to excellent reliability for VCO2, respiratory exchange ratio (RER), and tidal volume (VT).
• Pearson's correlation coefficients showed moderate to high correlations between PNOE and K5 measurements for all parameters.
• Bland-Altman plots demonstrated that most measurements fell within acceptable confidence intervals.

Conclusions:

• The PNOE system demonstrates strong validity and reliability for measuring cardiometabolic outcomes.
• The PNOE system's performance is comparable to the established COSMED K5 system.
• The PNOE system is a suitable tool for assessing respiratory gaseous exchange and energy expenditure.