1. What is the Physical Activity Coefficient?

The Physical Activity Coefficient (PA) is a dimensionless number that represents the ratio of total energy expenditure to basal metabolic rate. It provides a measure of how active a person is compared to their resting metabolic needs.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( PA \) — Physical Activity Coefficient (unitless)
• \( E \) — Total energy expenditure (kJ)
• \( BMR \) — Basal metabolic rate (kJ)

Explanation: The equation shows how much more energy a person expends compared to their basal metabolic needs.

3. Importance of PA Calculation

Details: The PA coefficient is important for assessing physical activity levels, designing exercise programs, and nutritional planning.

4. Using the Calculator

Tips: Enter energy expenditure and basal metabolic rate in kilojoules (kJ). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical PA values?
A: Sedentary: 1.4-1.6, Lightly active: 1.6-1.9, Moderately active: 1.9-2.5, Very active: 2.5-3.0, Extremely active: >3.0.

Q2: How is BMR measured?
A: BMR can be measured via indirect calorimetry or estimated using equations like Harris-Benedict or Mifflin-St Jeor.

Q3: What's the difference between PA and PAL?
A: Physical Activity Level (PAL) is similar but often calculated over longer periods (24 hours) and includes sleep time.

Q4: Can PA be less than 1?
A: Normally no, as BMR represents minimum energy needs. Values <1 might indicate measurement errors.

Q5: How accurate is this calculation?
A: Accuracy depends on precise measurement of both E and BMR. Estimated values will reduce accuracy.