Imagine the human body in a state of absolute stasis—a coma, requiring zero physical movement, digestion, or temperature regulation. The precise amount of energy required simply to keep the heart beating, the lungs expanding, and the brain firing is your Basal Metabolic Rate (BMR). It is the idle speed of your biological engine.
The Katch-McArdle Advantage
Most basic fitness trackers use the Mifflin-St Jeor equation to estimate BMR. That formula relies on total body weight, which introduces a severe clinical error: it treats a kilogram of dead adipose tissue (fat) the same as a kilogram of highly vascularized kinetic tissue (muscle).
VectoBody discards this standard. By utilizing your physical measurements to calculate Relative Fat Mass (RFM), the system isolates your exact Lean Body Mass. We then pass that data through the highly accurate Katch-McArdle formula:
Muscle as a Metabolic Furnace
The Katch-McArdle math reveals a critical truth: fat burns almost zero calories at rest. Muscle is biologically expensive to maintain. By increasing your lean mass through resistance training, you permanently increase your system's baseline BMR. You effectively upgrade the size of your biological engine, allowing you to consume more fuel (calories) while maintaining or reducing your total system mass.
Building to TDEE
Your BMR represents roughly 70% of your total energy output. Once the VectoBody engine calculates this baseline, it applies an operational multiplier based on your selected Activity Level and daily kinetic output. This combined figure becomes your Total Daily Energy Expenditure (TDEE)—the exact caloric ceiling you must operate beneath to trigger the Burn Protocol.