Indirect calorimetry during treadmill walking--a study of two methods

Area of Science:

• Physiology
• Biomechanical Engineering
• Rehabilitation Science

Background:

• Physiotherapy evaluation of walking requires objective measures.
• Energy expenditure measurement offers a valuable supplement to assess treatment outcomes.
• Treadmill walking provides a controlled environment for assessing energy expenditure.

Purpose of the Study:

• To assess the reproducibility of oxygen consumption measurements using two devices during treadmill walking.
• To determine if measurements are sensitive enough to detect differences in energy expenditure and respiratory quotient (RQ) at varying walking speeds.

Main Methods:

• Test-retest reliability study involving two metabolic monitors: Deltatrac and Sensormedics 2900.
• Subjects walked on a treadmill at comfortable and preset speeds for 10 minutes to achieve steady-state measurements.
• Measurements of oxygen consumption and RQ were repeated within two weeks.

Main Results:

• Both devices demonstrated acceptable repeatability for measuring energy expenditure and RQ.
• Both methods were sensitive to differences in energy expenditure across various walking speeds.
• The Deltatrac monitor yielded excessively low RQ values, likely due to airflow issues.

Conclusions:

• The Sensormedics 2900 is a reliable and sensitive tool for evaluating energy expenditure during treadmill walking.
• The Deltatrac monitor's limitations in RQ measurement make it unsuitable for this application.
• Objective energy expenditure data can enhance the evaluation of physiotherapy interventions for walking.