Sometimes I wonder if all that added muscle diverts blood flow away from the brain.

It is often the case that bodybuilders give some of the worst possible fitness advice. Many believe that huge = knowledgeable. This is not always so.

Here is a big picture recipe for success in bodybuilding:

  • More important than anything, be genetically gifted.
  • Take anabolic steroids plus an ungodly chemical concoction of many other things humans should probably not be putting into their bodies if they care about their health. If it’s for a competition where they screen for drug use, either use a masking agent or buy some clean pee. (Note: Some sarcasm intended. There are clean competitors.)
  • Lift a lot. I mean A LOT.
  • Eat a lot during bulking, but create a caloric deficit during cutting.
  • Avoid large amounts of aerobic activity, as it can decrease muscular gains.

That’s mostly it. There is a lot of bro-science that is an effort of separating fly shit from pepper stacked on top of it, but that formula up there is what makes usually makes for a tan-gooped and speedo-ed champion.

But, money.

Bodybuilding doesn’t pay much, but selling supplements does. A website called T-Nation is owned by a supplement company called Biotest. Sometimes, articles on the site are used to glorify supplements that are no better than chocolate milk. Other times, there are good articles, and sometimes, there are just plain factually challenged articles. The factually challenged articles I refer to aren’t written with the purpose of directly selling a supplement, but they’re intended to drive traffic to the site by being controversial and/or alarmist, and while you’re there you can expect to be bombarded with Biotest supplement advertising.

I want to respond to one such factually challenged article.

It’s an article that will probably be read by young and uninformed males who wants to get jacked and ripped because they think it will get them laid (which I would argue is an accurate description of the Biotest target marketing strategy). It’s an article that boils down to: Cardio sucks. Don’t do it.

Telling people cardio sucks is an old trick that drives a lot of clicks. And clicks = supplement sales.

Before we get started on this article, I do want to address one point I made about large amounts of aerobic activity decreasing muscular gains.

It’s true.

I have an article being published in early April that goes into great detail about this, and I interviewed probably the most knowledgeable man in the business about the science of muscular hypotrophy for that piece.

Suffice to say that bodybuilders should not be marathoners. High volume aerobic activity will inhibit the amount of muscle you can gain (inhibit, not stop). I’m not a bodybuilder, but a Boston qualifying marathon runner. I’m not huge, and I don’t want to be. But I’m not scrawny either. The photo on this site is my completely worthless N=1 anecdotal example of a guy who spends three hours on aerobic training for every one spent lifting. Because that’s how I enjoy spending my time.

Anyway …

This article in question is called “Regular cardio will make you fat.” I’ve said this before: Anything that is not currently suffering a cardiac arrest is “cardio.” Lifting and interval training make positive adaptations to your heart too. Distance running is not “cardio.” It’s “aerobic training.”

Before looking at the claims made in the article, let’s look at the author. He doesn’t look like much of a marathon aficionado, does he? That’s fine. Bodybuilding is obviously his thing. I won’t judge. I have no idea if he is enhanced in some way, and I won’t judge that either.

But I would appreciate the same courtesy be extended to me. I am judged by the bodybuilding crowd for running marathons and enjoying spending several hours on my bike cruising across the countryside. Tomes abound across the Internet about the evilz of da cardio, brah.

Here is the kind of thing I’m talking about:

“Finished up a squat/deadlift workout with 28,500 lbs of total volume. Keep your 2 hour cardio sessions… I’m training to be a monster, not a little cardio bunny”

That was a Facebook post by bodybuilder Layne Norton.

Good for you Layne. Go be a monster. Your career is wrapped up in it and you’ve obviously been successful. But why, in order to be successful, do you need to tear down people who engage in legitimate and popular forms of exercise? I’m nowhere near your size, and I don’t want to be. Still, I’m stronger and more muscular than the vast majority of men half my age, because I too like to lift. But I also run marathons and would like to complete an Ironman triathlon one day. Does that make me a “little cardio bunny”?

Is the fact that I prefer to be good at many physical activities (some of which are counter to one another in terms of developing capabilities) rather than excel at one specific thing mean I deserve to be insulted for my exercise choices? Running, cycling, swimming, and triathlons are all Olympic events. Bodybuilding is not, and probably never will be. Again, why is it okay to insult someone as a little cardio bunny for engaging in activities that are far more popular than removing all your body hair as a prerequisite to posing on stage while dehydrated.

Now that’s off my chest, let’s answer the question posed in the title.


Will regular cardio make you fat?

No. Eating too much will make you fat.

Let’s look at some of the claims made in the article.

Claim: “Now how does one become more efficient at slow, aerobic cardio? By decreasing overall energy output, which means burning fewer calories to do the same activity.”

My response: Uh, yeah. It’s called getting in better cardiovascular condition. If you’re in terrible shape and run a mile, then your heart is pounding and breath is labored. Your technique probably sucked too. You likely had pretty decent EPOC (caloric afterburn as high as 15% of total energy cost for the untrained) as well, being not adapted to such exercise.

If you get in shape by running lots, you will have better technique, which means less calories burned, and your heart and lungs will function more efficiently, which also means less calories burned. EPOC is lower too because everything goes back to normal quickly after the workout.

BUT! You gained the ability to run many more miles, which can burn a lot of calories if running becomes your thing.

Claim (paraphrased): All this cardio will cost you muscle, which lowers metabolic rate.

My response: If you’re bulked up as big as you can be and use running to burn fat off for a competition, It’s going to take a pretty ridiculous amount of running or other aerobic activity – along with some dietary stupidity – to get the body to favor burning muscle over burning fat stores, especially if you keep up a decent lifting regimen during those few months of cutting for competition. Will you lose more muscle than if you didn’t run at all? Probably, but the amount is up for debate. The point here though is not the muscular cost of high volumes of aerobic training. I’ve already acceded that lots of aerobic activity is at cross-purposes with building maximal muscle mass. The point here is about the claim that “regular cardio makes you fat.”

Perhaps you lose a little muscle. According to the author this is going to slow down your metabolism. This is perpetuating the myth that muscle has a high resting metabolic rate, and I busted that myth apart years ago for the LA Times.

The reality is, the amount of aerobic training you would need to do to have a noticeable muscular loss would burn far more calories than any resting metabolic cost from decreased muscle mass.


The Bigger Picture

Lean bodies are made in the kitchen.

It’s obvious that this article is targeted at people prepping for a contest, but mostly young men who will never step on a stage are the ones reading it. They skimming through and seeing that cardio is evil and gonna make me fat, yo, so I better not do it.

Let me lay out the role of aerobic training as a tool for fat loss for you. This is not from a bodybuilding perspective, which makes up about 0.2% of the population, but from the “I want to lose weight and be muscular” perspective, which makes up a helluva lot more than 0.2% of the population.


You need a caloric deficit to lose weight

Say you burn 2,500 calories a day sitting on your ass. If you want to lose two pounds a week, which is aggressive but still achievable weight loss, you’ll need a daily deficit of 1,000 calories (although note that when you’re losing weight, caloric deficits become a moving target).

You can keep on sitting on your ass, and take in 1,500 calories a day, and feel like you’re starving. An alternative to this could be to add in 500 calories per day worth of activity, and eat 2,000 calories per day, and feel less hungry. Better yet, you could add in a thousand calories of activity a day (that’s a lot, and it takes a lot of time and dedication to fitness to achieve such a level of sustainable daily exercise energy expenditure) and eat 2,500 calories a day and feel nice and full.

The caloric deficit is everything. Adding in activity that has a high caloric cost means you can still be in a deficit, but while eating more food, so there is less hunger. Hunger = life suckage = unsustainable.


Aerobic activity burns way more calories than weightlifting

As I pointed out, the whole muscle mass burns mega calories while you sleep thing is a myth. Weightlifting burns some calories, and it all adds up, but if you want to burn more, any type of aerobic activity will add up. Walking, jogging, running, cycling, swimming, hiking, boinking, Jane Fonda VHS tapes … Boinking while watching Jane Fonda VHS tapes … It all boils down to endurance activities that you can do for a long time, and the more you move, the more calories you burn. Shoveling snow. Raking leaves. Scrubbing toilets. It is even more calories burned, and makes achieving that caloric deficit that much easier to achieve as long as you …


Don’t eat like a moron

Here’s an important piece I did for my syndicated Chicago Tribune column about how exercise affects appetite.

Some people get dumb with exercise, thinking, I exercised, therefore I can eat. This kind of thinking undoes many a weight loss effort. As my Tribune article points out, exercise is actually a powerful tool for becoming a better eater, and aerobic activity is better for controlling appetite than resistance exercise is. Aerobic activity, especially the more intense variety, enhances the brain’s “executive function,” which controls your planning and decision making skills – skills that are valuable when it comes to sticking to a dietary regimen and resisting junk food. More intense aerobic training also has an appetite suppressing effect (so does interval training), whereas resistance training does not appear to have this same effect. Finally, aerobic training is found to be far better than resistance exercise at sating the neuro-chemical reward pathways in the brain that are the same reward pathways that can make us crave highly palatable junk food. In other words, aerobic activity makes your brain crave junk food less.

It’s true that many people undo these benefits by being dumb and adopting the reward mentality of “doing stairclimber = eating potato chips,” but that’s an easy enough habit to break once you know the facts.

And just FYI, that Tribune article only scratches the surface. My book goes into way more detail on how exercise affects eating behavior. Way more.


Can’t We All Just Get Along?

Bodybuilders: I’ll make you a deal. You stop calling runners “little cardio bunnies” or whatever, as well as stop spreading misinformation about the “evils” of aerobic traing, and I’ll stop making fun of your tanning goop and your speedo. And for the chemically enhanced, I won’t even say anything about the back acne, the bitch tits or the shriveled nutsack. Deal?


In Conclusion …

Do whatever the hell you want, but realize that if there is no caloric deficit, there is no weight loss. Aerobic activity is a great way to assist in creating such a deficit, as long as you’re not thinking it entitles you to apple pie a la mode after every workout. What it really does is entitles you to not starve.

I don’t care what your activity is. I run because I like it and because it’s effective for helping lose weight and maintain my weight. Also, traveling the world to run marathons is cool. I’ll be running Boston this year, and that’s going to be a once-in-a-lifetime experience, and the fact that some people think that makes me a little cardio bunny won’t diminish it. If there is something you like to do that gets your heart rate up, then just do it. The most important thing is to just be active.

Weight loss without activity almost always equates to hunger. And hunger is the real enemy when it comes to sustainable weight loss.

I made an assumption in this piece which I would like to remedy. As someone who has had many articles published in various media outlets, I know that writers rarely have control over the titles chosen for their articles. More than once I have winced when I saw the title chosen for my article.

Part of my reason for writing about this article arises from the title. I do not know if the author chose or approved that title. Perhaps he winced when he saw it, and the publisher is to blame for choosing something sensationalistic in order to drive clicks. If such is the case, and the author does not approve of that title, then I owe him a partial apology.

I am certain the author is well-versed in the science of building muscle, and there were good components to his article about the use of HIIT and sprinting. I wish to mention now that I was  impressed with his descriptions of the proper way to use these tools. However, there were certain erroneous claims made about aerobic exercise in regards to body weight that needed addressing.

This piece was first published on my old website on February 21, 2014.


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James S. Fell, CSCS, is an internationally syndicated fitness columnist for the Chicago Tribune, Los Angeles Times and He is the author of Lose it Right: A Brutally Honest 3-Stage Program to Help You Get Fit and Lose Weight Without Losing Your Mind, published by Random House Canada.