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Predicting Walking METs and Energy Expenditure from Speed or Accelerometry
- Published on 07/01/2005
Purpose a) Compare the predictive potential of speed and CSA(hip) (Computer Science Applications accelerometer positioned on the hip) for level terrain walking METs (1 MET = VO2 of 3.5 mL·kg-1·min-1) and energy expenditure (kcal·min-1); b) cross-validate previously published CSA(hip)- and speed-based MET and energy expenditure prediction equations; c) measure self-paced walking speed, exercise intensity (METs) and energy expenditure in the middle aged population.
Methods Seventy-two 35- to 45-yr-old volunteers walked around a level, paved quadrangle at what they perceived to be a moderate pace. Oxygen consumption was measured using the criterion Douglas bag technique. Speed, CSA(hip), heart rate, and Borg rating of perceived exertion were also monitored.
Results Speed explained 10% more variance of walking METs than CSA(hip). Speed and mass explained 8% more variance of walking energy expenditure (kcal·min) than CSA(hip) and mass. The best previously published regression equations predict our walking METs and energy expenditures within 95% prediction limits of +/- 0.7 METs and +/- 1.0 kcal·min-1, respectively. Women paced themselves at a significantly higher mean speed (5.5 km·h-1) and intensity (4.1 METs) than their male counterparts (5.2 km·h-1 and 3.8 METs). Both genders expended approximately 0.75 kcal·kg-1 for every kilometer of level terrain walked.
Conclusion Speed-based MET and energy expenditure predictions during level terrain walking were more accurate than those utilizing CSA(hip).
Link to Abstract: http://www.ncbi.nlm.nih.gov/pubmed/16015141
Medicine & Science in Sports & Exercise