Question

Describe the relationship between exercise intensity and fuel selection. Make sure to use RER as a benchmark for our understanding of this.

Answer 1

Exercise intensity can be determined through the amount of energy required to perform a physical activity.
A higher exercise intensity requires the body to perform greater work and thus more energy is required to carry out high intensity exercise.
A low intensity exercise requires involves less work performed by muscles and thus less energy is required.
The energy required by the muscles to perform work is generated through the carbohydrate, fats and protein store. These macronutrients act as a fuel for energy production.
The fuel selected for energy production directly depends on the intensity of the exercise.
During a low or moderate intensity exercises body generates energy through aerobic pathways bu utilizing the carbohydrates and fats as the fuel.
At high exercise intensity the carbohydrate and fat stores depletes rapidly and the muscle glycogen stores are used as fuel to generate energy.