There have been tons of articles and studies done on this topic and truth be told, just about any article or study can be skewed to support any argument. There is plenty of information out there that supports this argument and lots of information that doesn’t.
So does it, or doesn’t it? As far as I can tell, there really isn’t a black or white answer to this question and many more shades of grey.
Recently, my friend, Will Brink, author of Fat Loss Revealed, discussed this topic with his followers. Will is a man of science and when Will talks, I listen.
Will explains it this way.
The body dictates storage of fat over weeks, months and years. Not over periods of time like 20 minutes, 30 minutes, 40 minutes, etc.
The basic theory about doing cardio in a fasted state is that you will burn more fat because your glucose will be low and you won’t have carbohydrates in your blood stream.
According to Will, there doesn’t appear to be any metabolic advantage to doing this. It’s about total calories burned.
Workout intensity also plays a role in calories burned doing exercise. If you’re not working out intensely, your basically spinning your wheels. Many people can’t workout intensely first thing in the morning on an empty stomach, myself included.
Overall, there really aren’t any metabolic advantages to doing fasted cardio.
My other trusted fat loss go-to source is Tom Venuto, author of Burn the Fat.
In one of Tom’s articles, he cites studies that support that theory that cardio first thing in the morning burns fat. He also cites studies that negate this theory.
So what’s Tom’s bottom line on this topic?
In conclusion, it seems that A.M. cardio has enough indisputable benefits to motivate most people to set their alarms early. But let’s talk bottom line results here: Does doing morning cardio in a fasted state really result in more “real world fat loss” than cardio performed at other times of the day or after eating? I have to believe it does. Common sense, research and experience from 28 bodybuilding competions all tell me so. Nevertheless, this will obviously continue to be an area of much debate, and clearly, more research is needed. In the meantime, while the scientists are busy in their labs measuring respiratory exchange ratios, caloric expenditures and rates of substrate utilization, I’m going to keep waking up at 6:00 AM every morning to get on my Stairmaster for some (pretty intense) cardio.
Craig Ballantyne, author of Turbulence Training chimed in on this topic in a recent email. Craig opened up stating
Today we’re going to cover one of the biggest myths in
fitness. The one that says:
“You should do cardio on an empty stomach to burn more fat.”
I bet you know where this is going…after all, I just
called it a myth.
He then went on to cite a study to back up his response to this topic.
Well, first we have to go all the way over to Italy, to hear
from researchers who had a study published in the International
Journal of Sports Nutrition Exercise and Metabolism (21:48-54, 2011).
The Italian researchers wanted to see what would happen
when eight healthy young men did the following workouts:
Workout A: 36 minutes of slow cardio at 65% maximum heart
rate in the morning without eating
Workout B: 36 minutes of slow cardio at 65% maximum heart
rate in the morning AFTER a small meal
24-hours after exercise, the results found that eating before
cardio increased both calorie burning AND fat burning.
That’s right, eating before the workout increased fat burning
in the 24-hours after exercise.
The scientists concluded that “fasting before exercise does
not enhance lipid utilization; rather, physical activity
after a light meal is advisable.”
The truth about fasted cardio is that it is NOT a magical
way to boost fat burning.
But the REAL TRUTH about cardio in general is this:
You’re not going to get the best results from slow cardio,
fasted or fed. We’ve covered that dozens of times in our TT
newsletters here, and you already know to skip it and use
interval training or bodyweight exercises instead.
And there you have it. Three fat loss experts I admire, trust, look up to and respect with different conclusions on this topic.
So, where do I stand on all of this? For me, personally, I’m not doing ANYTHING first thing in the morning on an empty stomach. I tried it and it was hell. My strength, stamina and endurance was kaput. I’m just not a morning person. Not only that, but I was not left feeling energized the rest of the day which affected my strength training workouts. For me, this is a moot point.
I workout mid morning after having had a light breakfast (and yes, lots of coffee too!) and do much better and have energy the rest of the day. If I’m looking to drop body fat, I workout twice a day and tighten up my diet. I do one strength training session mid morning and a cardio session later in the day. For me, it’s all about having the energy to give it my all during my workouts and creating a caloric deficit through diet and exercise.
On the other hand, some people are morning people and do great working out first thing in the morning. If you’re one of those people than by all means, go ahead and do fasted cardio in the morning, however, it’s not a guaranteed way to burn body fat without the right balance of calories and macronutrients.
In conclusion, my advice is for you to do what’s best for you. Your body will let you know what’s right for you. I know that’s not a science based answer. I’ll leave that up to Tom, Will and Craig, but it’s my common sense answer.
To find out more about Will Brink, click here —> Fat Loss Revealed
To find out more about Tom Venuto, click here —> Burn the Fat
To find out more about Craig Ballantyne, click here —> Turbulence Training