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Energy Expenditure Calculator

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Personal Information

kg
cm
years

Activity Parameters

💡 Enter distance + duration for precise calculation
min
km

Advanced Parameters (for more precision)

°C
m
m
W
bpm

Energy Expenditure Results

- kcal
Total energy expenditure
-
Activity
-
Duration
-
Distance
-
Elev.

Calculation Methods Used

Method Priority Order

  1. Power (cycling only): Most precise ±5%
  2. Distance + time (running): Specifically calibrated ±10%
  3. Heart rate: Scientifically validated formula ±10%
  4. MET: Standard method based on activity ±20%

Factors Considered

  • Male/female metabolic differences
  • Metabolic decline with age
  • Impact of elevation on effort
  • Influence of temperature
  • Speed and intensity of effort
  • HR adjustment to refine real intensity
Important : Results are scientifically based estimations but may vary according to your individual metabolism (±10-15%). For maximum precision: use a power meter (cycling) or enter the distance covered (running).

Scientific guide to the calorie calculator

Our calculator uses 4 scientific methods in order of precision:

  • Mechanical power (cycling) - ±3-5%: Calories = (Power × Duration × 3600) / (Efficiency × 4184). Efficiency: 24% (men) / 22% (women).
  • Distance + Duration (running) - ±8-12%: ACSM formula VO₂ = (0.2 × speed) + (0.9 × speed × grade%) + 3.5
  • Heart rate - ±10-15%: Keytel et al. formula (2005), validated on 100+ subjects.
  • Metabolic equivalent (MET) - ±15-25%: Calories = MET × Weight × Duration, based on the 2024 Compendium.

We use the Minetti polynomial formula (2002) which accounts for both uphills AND downhills:

C(i) = 155.4×i⁵ − 30.4×i⁴ − 43.3×i³ + 46.3×i² + 19.5×i + 3.6

  • Uphills: Cost increases exponentially with gradient
  • Downhills: U-shaped cost with minimum at −10% (eccentric muscle braking)
  • Steep slopes: Significantly higher cost

Reference: Minetti et al., Journal of Applied Physiology, 2002

The extra energy cost comes from terrain technicality:

  • Road / Track: Reference (0%)
  • Path / Gravel: +5% (Vernillo et al., 2016)
  • Technical trail: +10% (instability, adaptation)
  • Very technical: +15% (rocks, roots, obstacles)

Important: Trail does NOT have an automatic surcharge. On identical terrain, trail = road running.

Tanaka et al. formula (2001): HRmax = 208 − (0.7 × Age)

This formula replaces the obsolete "220-age" with better accuracy (±10 bpm vs ±15 bpm).

Meta-analysis of 18,712 subjects - Journal of the American College of Cardiology, 2001

Values from the Compendium of Physical Activities 2024:

  • Running: 8.3 MET (8 km/h), 10.0 MET (10 km/h), 11.5 MET (12 km/h), 12.8 MET (14 km/h), 15.3 MET (16 km/h)
  • Cycling: 6.8 MET (<16 km/h), 8.0 MET (16-19 km/h), 10.0 MET (19-22 km/h), 12.0 MET (22-25 km/h), 15.8 MET (>25 km/h)

MET automatically adjusts according to your actual speed.

Age: Metabolic decline of −0.5%/year after 40 years old

Temperature:

  • <0°C: +15% (intense thermoregulation)
  • 0-10°C: +8% (moderate cold)
  • 10-28°C: Comfort zone (no adjustment)
  • 28-35°C: +12% (significant heat)
  • >35°C: +20% (major thermal stress)

Note: These calculations are estimates based on averages. Your individual metabolism may vary results by ±10-15%.