My advice is “not”. The reason most people do fasted cardio is to burn fat, so to understand my advice you must first understand how and when you burn fat during a cardio session.
Doing your cardiovascular workout in the morning means that your muscles are fairly depleted of glycogen. Carbohydrates that you eat are converted to glycogen and stored in the muscle as a source of energy. When you wake up in the morning many hours have past since your last meal of carbohydrates so your glycogen levels could be at the lowest point of the day. When you do your aerobic workout, if there is glycogen in your muscles, that will be the first source your body will turn to for energy. When your body has depleted those stores (5-15 minutes) the oxygen that is being pumped into your blood will oxidize fat for energy. Therefore, the less glycogen in the muscle when starting your aerobic workout, the sooner you start depleting fat stores. Am I making any sense yet?
So, my advice of “not” doesn’t seem logical huh? Well, I didn’t tell you to eat carbohydrates before your morning cardio, did I? No, I just said that I didn’t advise fasted cardio. I do believe in having a serving of protein prior to doing your morning cardio. Protein in the morning will help elevate growth hormone levels, pick up your metabolism and protect your muscle tissue from breaking down and will NOT slow down the fat burning process, now that’s all good right?!
Remember, I’m talking about a morning aerobic workout where your goal is to burn fat, not to work on speed/distance/endurance goals.
What protein you choose to eat is up to you but to keep it simple I would suggest a protein drink…what do you eat before your morning cardio workouts?