e Measuring the metabolic rate k Direct calorimetry x Indirect calorimetry Principle: The law of constant proportions Several related concepts Thermal equivalent of food Thermal equivalent of oxygen Respiratory quotient(rQ) Classical simple measurement O2 consumption co2 production measuring Closed opened measurement• Measuring the metabolic rate * Direct calorimetry * Indirect calorimetry Principle: The law of constant proportions Several related concepts Thermal equivalent of food Thermal equivalent of oxygen Respiratory quotient (RQ) Classical & simple measurement O2 consumption & CO2 production measuring Closed & opened measurement