Robert spent about three days in the metabolic chamber - a sparse box containing a bed and a toilet that’s designed to produce precise measures of metabolic activity - before and after the exercise test. (I will expand on the metabolic chamber). He wore an EEG, blood pressure and Holter monitor, while in the chamber.Only thirty metabolic chambers exist in the world, and
three of them are at the NIH. With 400 metabolic chamber studies underway every year, they're pretty much in use all the time. These airtight 11-by-11.5-foot rooms aren't much to look at or stay in: they come with a bed, an exercise bike, a toilet, and nothing else. Precisely measured meals are delivered through a small, air-locked opening in the wall.
Metal pipes running along the ceiling that measure oxygen consumption and CO2 production allow researchers to precisely calculate an individual's metabolic rate. From the O2 and CO2 readings,
researchers can calculate calories burned and what type of fuel (carbs/fats) was used to burn them.