Calories Burned

Unit: kcal

Calories burned represents total daily energy expenditure (TDEE), comprising basal metabolic rate (BMR), thermic effect of food, and activity energy expenditure. Wearables estimate calories using heart rate, motion, and user demographics (age, weight, height, sex). Accuracy is typically ±15-25% compared to doubly-labeled water or indirect calorimetry. Heart rate-based estimation improves accuracy over accelerometer-only methods. Significant individual variation exists in metabolic efficiency. Calorie data is useful for relative comparisons (yesterday vs. today) rather than absolute values. For weight management, tracking trends over weeks is more meaningful than daily figures. Exercise calories are often overestimated, leading to compensatory overeating. Energy expenditure decreases with weight loss through metabolic adaptation.