Scientific methodology
The MET index explained
Calorie burn calculation is based on the Metabolic Equivalent of Task (MET), the internationally accepted scientific standard for quantifying the energy expenditure of any physical activity.
What is the MET?
The MET (Metabolic Equivalent of Task) measures the intensity of an activity relative to resting metabolism. MET = 1 equals sitting at rest. Walking has MET 3.5 and running can exceed MET 11.
Calculation formula
Kcal =
MET × weight (kg) × time (h)
Example: running (MET 10) × 80 kg × 0.5 h = 400 kcal
Variables that affect it
- Body weight: more weight means more calories burned.
- Intensity: MET reflects relative effort.
- Duration: expenditure is linear with time.
Frequently asked questions
All About Calories Burned
Clear, evidence-based answers about energy expenditure and physical activity.
Calories burned are calculated with the MET index formula: Kcal = MET × weight (kg) × duration (h). The MET (Metabolic Equivalent of Task) indicates the intensity of each activity relative to resting metabolism. A MET of 1 equals sitting still; normal-pace walking has MET 3.5 and running at high speed can exceed MET 11. This formula is the international scientific standard for estimating exercise energy expenditure.
The activities with the highest caloric expenditure are high-speed running (MET 11.5), skipping rope (MET 10), running at 10 km/h (MET 10) and intense swimming (MET 9.8). For a person weighing 80 kg, running at 12 km/h for one hour burns approximately 920 kcal. HIIT is also very effective because it combines high intensity with recovery periods that keep metabolism elevated for hours.
Walking at a normal pace (MET 3.5) burns around 280 kcal/hour for a person weighing 80 kg. At a brisk pace (MET 4.5) the expenditure rises to about 360 kcal/hour. In 30 minutes of normal walking, a person weighing 70 kg burns approximately 122 kcal. Exact values vary depending on weight, terrain gradient and actual speed.
Yes, energy expenditure is directly proportional to body weight. A person weighing 100 kg burns 25% more calories than one weighing 80 kg performing the same activity for the same time, because more energy is needed to move greater mass. That is why losing weight makes exercise burn fewer calories, but the cardiovascular and metabolic benefits remain just as important.
A deficit of approximately 7,700 kcal is needed to lose 1 kg of body fat, equivalent to running about 77 km for a person weighing 80 kg. The most effective approach is to combine exercise with a moderate caloric deficit diet (300–500 kcal/day), which allows losing approximately 0.5 kg per week in a sustainable and risk-free way.
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