The effectiveness of cardio training performed in the morning is a question commonly asked of fitness professionals--especially considering the challenges of fat loss. You’ll find it trumpeted in fitness forums and blogs and even on our Facebook page. But does it work? Sort of. Morning Cardio training on an empty stomach or while fasting is a common practice within the bodybuilding community to ensure lowest possible body fat prior to competition. Training and fitness expert Jesse Burdick shares, “Fasted cardio is the prevailing wisdom in bodybuilding because these guys are dieting very hard.” The reason why this particular training approach is effective concerns the depletion of glycogen, the body’s first source of stored energy. By keeping the body drained of this stored form of glucose, it’s then forced to burn fat or protein instead. According to training and fitness expert John Kiefer of DangerouslyHardcore.com, “When you’re fasted in the morning, the hormone cortisol is high and its only job is to break down the appropriate tissue based on what other hormones are around. Insulin is elevated after eating and cortisol will attack muscle. But, if you are fasted, insulin is low and cortisol will then go after body fat reserves.” As far as the types of cardio you should do, Burdick suggests 15-20 minutes or less of high-intensity interval training or low-to-moderate intensity steady-state cardio. What about the regular guy who wants to maintain his typical diet without fasting? Will cardio training in the morning be any more effective than at other times? Nope. Kiefer says, “On a regular, normal diet, there really is no difference in how much fat you will burn.” Both men agree that training in the morning is good for getting the body energized, but unless you’re fasting, you might be better off getting those extra Z’s for a hardcore evening session.