Fasted Cardio: There are so many different views, opinions and reasons for people to do fasted cardio. Some people LOVE it and some people absolutely HATE it. Some just can't do it due to training on empty bellies makes them nauseous and some just think it is so stupid for muscle loss purposes.
Keeping it basic, our bodies get its energy first from Glycogen (carbohydrates) then from fat and then from protein. When your cells have a lot of Glycogen to spare this is where your body will get its energy from first.
Fasted cardio is cardio performed after a "fast" (aka sleep). So while you were sleeping, your body uses much of its glycogen stores. So people believe by performing cardio in the morning on an empty stomach, the idea is that you tap into your 2nd energy source, FAT to fuel your workout. I don't think it's smart to do HIIT cardio (high intensity) fasted but a low to moderate steady cardio is ideal.
Muscle Loss is the main concern during fasted cardio and a big reason some people think it is stupid to train fasted. Supplementing with 5-10g of BCAAs before your cardio will ensure your body has sufficient supply of amino acids and won't have to start breaking down muscle tissue to get it. BCAAs are needed in high amounts under conditions of stress or exercise. And unlike most amino acids that first must go through the liver, BCAAs are sent directly to the muscles.
I have never had a problem doing fasted cardio. I don't get nauseous or feel less energy when I do it. I do supplement with BCAAs each time to help aid and protect lean muscle and less fatigue during my workout. I choose to do it because of the science behind it- tapping into fat stores. My dang outer thighs!
www.cellucor.com is where I get my BCAAs. All flavors taste like jolly ranchers. Watermelon is my favorite. HALEYA is the discount code for 25% off and free shipping.