Coal
Coal is a combustible black rock that is formed from prehistoric plant remains. Coal is formed from the anaerobic decomposition of dead plant matter such as trees, ferns, mosses and other marsh plants that grew on the earth surface over millions of years ago. Coal is composed largely of carbon and is usually burned as a fuel.
The right answer is to measure the amount of released carbon dioxide.
The carbon dioxide exhaled by the lungs can reflect the energy consumed by the body since it comes from the degradation of glucose which is the main energy substrate. And this is a better indicator of energy consumption than measuring heart rate because it can be inflected by several factors.
A is false because glucose is not found in the urine, except in the case of diabetes mellitus.
C is false because the consumption of calories does not mean that we will directly use it.
D is wrong because perspiration is independent of energy consumption, this is a way to cool the body after exercise.
José probably doesn't feel any pain because his body, during and after exercise released endorphins which are endogenous opioids. This endorphins promote a sense of satisfaction and pleasure, and make pain and discomfort feel irrelevant.
