The measurement of metabolic rates is central to important questions in many areas of physiological research. Unfortunately these measurements are anything but straightforward, with numerous pitfalls awaiting both the novice and even the experienced investigator. The original edition of this work, published in 2008, quickly became the principle "how to" manual for the field. It successfully de-mystified the topic, explaining every common variation of metabolic rate measurement. Background information on different analyzer and equipment types allowed users to choose the best instruments for their application. Respirometry equations, normally a topic of terror and confusion to researchers, were derived and described in sufficient detail to facilitate their selection and use. In this new edition, the content has been thoroughly updated and a decade of new literature incorporated. New chapters on room calorimetry, human metabolic measurement, and metabolic phenotyping have also been added.