“There is evidence, for example, that exercising before breakfast (i.e. in a fasted state) leads to more fat-burning.”
Those who are not looking to burn fat and want to hit personal goals instead could benefit from later workouts.
This is because exercising in the afternoon or early evening could help improve performance, Dr Mosley added.
He said: “If you are interested in performance, then late afternoon or early evening may be a better time to work out.”