There are mixed feelings about this subject, I'll give my input on both and you can decide where you fit in. First lets talk about eating before cardio, for me it all depends on the time of day. If I have to do cardio early in the morning, which for me, cardio anytime before noon is considered early, and what I consider cardio most might not think so. My type of cardio is play ball, basketball, racquetball, volleyball or whatever I get called up to play. I can't just run on a treadmill, do the elliptical, ride the bike or step my way to a stepper in a gym. Maybe I lack the mental drive to just do plain cardio. With that being said, I have to have a little something to get me going, whether it's a piece of fruit, bagel, some oatmeal, protein shake, I just have to have something. And having something, we know starts up your metabolism, and sleeping 6-8 hours a night your body is in a fasting state, so for me it's crucial that I eat something before I start my day. Of course I do wait at least 15-30 minutes before I go play which means, after I eat, I will have to get dressed, brush my teeth, drive to the gym and depending how far I have to go, that's plenty of time for me. Now most of you that put more emphasis on gaining muscle mass or maintain muscle mass would agree with me and for those that put little emphasis on muscle mass and more emphasis on losing weight will disagree. So now lets talk about cardio on an empty stomach.
Some people or most can't eat anything that early in the morning, when I talk about eating early in the morning I'm talking about 7:30-8:00am. So for those that are more interested in losing weight, all they want to do as soon as they wake up is get going. They don't want to have to eat and then wait then finally go to the gym. Those fitting into this category feel nauseous when they eat and then go to the gym, the ones that I have talked to anyways. My theory behind exercising (cardio) on an empty stomach is this, once you wake up your body is pretty much empty of everything (meaning nutrients). With nothing in your system your body can't really depend on anything for energy except fat and of course muscle. You're probably wondering why muscle is being used for energy. Well when you wake up, you didn't feed it anything, so your body has nothing to depend on for energy. And we know that carbohydrates are the main fuel for the body's energy. And depending on how big you are your body might or might not tap into the muscles for energy and hopefull fat is the only fuel your body is using for energy.
So when it comes down to it, it all depends on your goal, if you want to lose weight and you feel nauseous eating before exercising than do it on an empty stomach. And if you're trying to maintain muscle mass then you should try to eat a little something before exercising. I hope this helps for those checking out my blog. Always remember "it's not how many hours you put in, it's what you put in the hours." Train hard and smart and train to succeed, and choose the Correct Training Regimen.