The debate regarding fasted cardio can and will go on forever. Some people swear by it while others dismiss it like the Shake Weight. Unlike the Shake Weight, there is some merit to fasted cardio, which I will do my best to summarize here.


Numerous studies have been done on the subject and I’ll summarize one that I particularly found interesting. I felt that this study was well done and incorporates more than just the effects on fat loss.

The study was performed on 20-30 year old males that have participated in regular physical activity for the past 12 months. The only thing I found that could have been improved here was the quality of the participants. Now I don’t usually pay attention to BMI (Body Mass Index) because I find it to be a useless number, however I do pay attention to body fat percentages. BMI doesn’t factor in lean muscle mass or bone/organ mass. According to the BMI measurement NFL players are obese. I’ll agree that some offensive linemen are a little hefty, but wide receivers and running backs? Have you seen these guys without their pads on? They are ridiculous! But I digress.


The average body fat percentage for the study of 22.4%. To me that seems a decent representation of the general populous; however I would like to see a lower body fat percentage study done to see how the athlete or bodybuilder responds to the same study. Maybe one day I can design my own study.

The study subjects performed steady state cardio for 36 minutes at a 65% VO2 max either in a fasted or fed state. VO2 max is the amount of oxygen that an athlete can use. Blood was drawn before exercise (baseline) and 15 minutes after exercise. The study showed what bodybuilders have been saying for decades. The fasted blood samples after workout had about a 50% increase in triglycerides as apposed to the fed blood samples with about a 20% increase.

So what does this mean? The body releases fat stores to help the provide energy when training in a fasted state.

Someone call the press we have the ultimate breakthrough in fat loss.

Not quite. Too much cardio in a fasted state will start breaking down muscle as well as releasing fat for energy. So your gains that you worked so hard for….out the window.

I’d also like you to think about the Snickers commercials where they say that you aren’t you when you’re hungry. Which is 100% true. When your blood sugar drops you get sleepy and cranky. Ever try a low carb diet? Same principle. Ask my wife when it’s contest prep time.

I love breakfast too much to skip it and go straight to the gym. But that’s me. I know some people that can wake up, down some pre-workout and start lifting. That’s not me. I’d rather put two workouts in than to skip breakfast. Personally I’ve found doing a cardio workout before bed keeps my metabolism going through the night and I can still kill it in the gym the next morning.

If your going to try fasted cardio, start with steady state (jogging, running, walking) for 10 min. After a few weeks, go to 15 and then 20 min. Work your way up 30 min but I wouldn’t go more than that. Remember too much taps into your gains.  Start slow. Where can you go when you start at 30 min? Another thing to consider is to add some variation by switching up the mode of cardio. You can switch from jogging to walking to running or even throw in some intervals. Sprint for 30 sec and walk for a minute and repeat 8-10 times.

In the end it is entirely up to you but you have to listen to your body. If you can’t function without eating something before a workout, then eat. My objective is to educate you enough information and options to make your own choices. What works for me might, not work for you.