Is Fasted Cardio More Effective for Fat Loss
Fasted cardio has long been touted as being more efficient for burning fat. This was thought to be more efficient due to insulin levels being low in the morning and insulins being responsible for suppressing lypolisis (the breakdown of fat).
This would allow more fat available for fuel. It was also thought that since glycogen (carbohydrates store in muscle tissue) levels were also low in the morning your body would again turn to fat instead of carbohydrates as fuel.
One study researched whether it was more beneficial to do cardio fasted or fed cardio over a 4 week period. Calorie and macronutrients were matched between the groups and by the end of the study no difference in fat loss was found.
Another study found that even if you do use more body fat during a fasted cardio session your body will end up balancing it out by using more glycogen instead of fat later in the day.
Remember its the total calorie balance throughout the day that leads to fat loss. But if you enjoy doing your cardio fasted then by all means do so. The best fitness program is always the one you can both stick to and enjoy.
Travis Moss
Online Evidence Based Personal Trainer
MVMNT Wellness
References:
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4242477/
2. https://www.ncbi.nlm.nih.gov/pubmed/15896087/