Calibration of the Computer Science and Applications, Inc. accelerometer

Area of Science:

• Exercise Physiology
• Biomedical Engineering
• Physical Activity Measurement

Background:

• Accurate assessment of physical activity intensity is crucial for health research.
• Metabolic Equivalent of Task (MET) categories are commonly used but require objective measurement tools.
• The Computer Science and Applications, Inc. (CSA) activity monitor is a widely used device for quantifying physical activity.

Purpose of the Study:

• To establish specific accelerometer count ranges for the CSA activity monitor.
• To correlate these counts with established Metabolic Equivalent of Task (MET) intensity categories.
• To provide a validated method for classifying physical activity intensity using the CSA accelerometer.

Main Methods:

• Fifty adults (25 males, 25 females) performed treadmill exercise at three speeds (4.8, 6.4, 9.7 km/h).
• Activity counts from the CSA monitor and steady-state oxygen consumption were recorded simultaneously.
• A predictive model for energy expenditure was developed and cross-validated.

Main Results:

• A strong correlation (r=0.88) was found between CSA activity counts and oxygen consumption.
• Specific count ranges were defined for light (<=1951), moderate (1952-5724), hard (5725-9498), and very hard (>=9499 cnts/min) intensity levels.
• The predictive model for energy expenditure showed high accuracy (r2=0.82) and was validated across different speeds.

Conclusions:

• The established count ranges provide a reliable method for classifying physical activity intensity using the CSA accelerometer.
• This research offers a practical tool for researchers and clinicians to categorize activity patterns.
• The findings facilitate objective assessment and comparison of physical activity levels across studies.