Respiration is a special form of burning fuel. It involves the burning of sugar with oxygen, within the cells of every living organism to produce the energy needed for all the reactions of life along with water and carbon dioxide as waste products. Respiration is another exothermic reaction.
Respiration is the sum of the chemical reactions that release energy from food molecules. To know that respiration can be represented by a word equation:
Glucose + Oxygen → Carbon dioxide + Water
and this reaction releases energy. However, energy is usually transferred as heat energy, so one way to tell if a chemical reaction is happening is to use a thermometer. If the temperature increases during a chemical reaction then that is an exothermic reaction.