Accelerometer output and MET values of common physical activities

Area of Science:

• Exercise Physiology
• Biomedical Engineering
• Physical Activity Research

Background:

• Accurate measurement of physical activity intensity is crucial for health research.
• Existing compendiums of physical activity energy expenditure may not reflect real-world metabolic responses.
• Metabolic Equivalent of Task (MET) values are commonly used but require validation.

Purpose of the Study:

• To calibrate metabolic and activity monitor data collection methods.
• To compare measured MET values with those from the Compendium of Physical Activities.
• To examine the relationship between accelerometer output and METs across various activities.

Main Methods:

• 277 participants performed 11 distinct physical activities for 7 minutes each.
• Oxygen consumption (VO2) was measured using a portable metabolic system.
• Accelerometers were used to record activity counts per minute.

Main Results:

• Measured MET values differed from compendium MET values for 81% of activities.
• Accelerometer counts per minute varied widely, from 11 (dishes) to 7490 (treadmill).
• The correlation between accelerometer counts and METs was moderate (r=0.65).

Conclusions:

• The Compendium of Physical Activities requires updates with empirical data.
• Linear regression models are inadequate for predicting METs from accelerometer data.
• This study offers insights into metabolic responses and accelerometer utility for diverse physical activities.