Research surrounding fasted workouts continues to develop. Studies have shown that there can be advantages to exercising in a fasted state. It can increase fat oxidation, result in lower energy intake throughout the day, and contributes to autophagy, the process in which the body destroys damaged cells and regenerates new, healthy cells. Exercising in a fasted state can therefore be advantageous for those looking to lose or maintain a healthy weight, as well as for overall health.
Despite these promising findings, fasted exercise is not for everyone. Upon waking in the morning, there is an increase in the hormone cortisol, which helps us get up and start the day. However, other conditions including stress as well as exercise similarly causes an increase in cortisol. It may therefore be wise to avoid fasted exercise when stressed to prevent a chronic state of elevated cortisol, which can be detrimental to health.
Furthermore, women should practice fasted exercise with caution, as they can be more sensitive to these cortisol spikes. This may be particularly true during menstruation, when hormone fluctuations can contribute to feelings of fatigue. Additionally, pre-exercise fueling may be beneficial when engaging in long endurance events, contributing to improved performance and delaying fatigue.
Given that the science surrounding fasted workouts is conflicted, determining whether or not to engage in this practice will ultimately be a personal decision. If you feel it is right for you, consider implementing it every other day and observe how you feel. Fasted exercise may be one tool in your arsenal, but it is certainly not for everyone, or for everyday.
