Calculating METs Scores and Intensity Classification

Basic Calculation Methods

• The American Heart Association recommends dividing the measured oxygen consumption (VO₂) by 3.5 mL/kg/min to convert absolute oxygen uptake into METs, for example, if someone consumes 17.5 mL O₂/kg/min during activity, this equals 5 METs (17.5 ÷ 3.5 = 5) 3
• The European Heart Journal suggests using standardized MET values from activity compendiums that list energy costs for specific activities, such as walking at 3-4 mph = approximately 3-4 METs, however a more accurate source states brisk walking at 4.8-6.5 km/h = 3-5.9 METs 5
• The American College of Cardiology recommends calculating METs from treadmill speed and grade using standardized equations, though this method has significant error, for instance, at 0% grade: walking at 2.0 mph = 2.5 METs, 3.0 mph = 3.3 METs, 3.75 mph = 3.9 METs 6

Intensity Classification Using METs

• The British Journal of Sports Medicine classifies light intensity as 1.5-3.0 METs (slow walking, bathing, light household work) 1, 7
• The European Heart Journal classifies moderate intensity as 3.0-5.9 METs (brisk walking, slow cycling, gardening) 1, 5
• The European Heart Journal also classifies vigorous intensity as ≥6.0 METs (jogging, running, swimming laps, singles tennis) 5

Calculating Total Physical Activity Volume

• The American Heart Association recommends multiplying intensity (METs) × duration (minutes) × frequency to calculate total MET-minutes per week, for example, 3 METs × 30 minutes × 5 days/week = 450 MET-minutes/week 3

Important Clinical Caveats

• The American Journal of Respiratory and Critical Care Medicine notes that the standard 1 MET = 3.5 mL O₂/kg/min is a convention that may not reflect actual resting metabolic rate for all individuals 2
• The European Heart Journal states that fitness level matters: the same absolute activity (e.g., 3 METs) represents different relative intensities for fit versus unfit individuals 5
• The American College of Cardiology warns that holding treadmill handrails decreases the metabolic cost and underestimates true METs 6
• The Circulation journal notes that body weight affects absolute energy expenditure: heavier individuals expend more total calories but similar METs for the same activity 3