Measuring metabolic rates is central to important questions in many areas of scientific research, including the human obesity epidemic. Unfortunately these measurements are anything but straightforward, and numerous pitfalls await the novice and even the experienced investigator. Measuring Metabolic Rates de-mystifies the field, explaining every common variation of metabolic rate measurement, from century-old manometric methods through ingenious syringe-based techniques, direct calorimetry, aquatic respirometry, stable-isotope metabolic measurement and every type of flow-through respirometry. Each variation is described in enough detail to allow it to be applied in practice. Background information on different analyzer and equipment types allows users to choose the best instruments for their application. Respirometry equations - normally a topic of terror and confusion to researchers - are derived and described in enough detail to make their selection and use effortless. Vital topics such as manual and automated baselining, implementing multi-animal systems, and the correct analysis and presentation of metabolic data are covered in enough detail to turn a respirometry neophyte into a hardened metabolic warrior, ready to take on the task of publication in peer-reviewed journals.