

There is wide variation in the time of day that people choose to exercise. The idea of performing fasted cardio training in the morning to accelerate fat burning is based on a key assumption that without food in our system and lower levels of glycogen available, our fat stores are the go-to energy source. This assumption was recently put to the test by researchers from Japan, who recruited 10 young, healthy, recreationally active (untrained but performed moderate-intensity exercise 2-4 days/week) men to perform four experimental sessions locked within a metabolic ward. This is a tremendous strength of the study, as the metabolic ward allowed for complete control and analysis of the participant’s life for the time they spent inside. Over the course of two months with at least 1 week between experimental sessions, the participants stayed within the metabolic ward for three days to allow for standardization of the experimental protocols....


