Hey Fitties! Long post today… but it’s a subject near and dear to my heart. So hang in there.

I’ve wanted to blog about Chunky Aerobics Instructor Syndrome (CAIS) for awhile.  CAIS is attributed to Charles Poliquin, a respected strength and conditioning coach, who used the term to describe aerobics instructors who, despite teaching 5 to 8 hours of aerobics a week, have “surprisingly high body-fat percentages considering the amount of activity they do.”  CAIS proseltyzers provide convincing biochemical explanations about why cardio is the fat cell’s friend and why cardio junkies are “chunky” or “chubby.”  A lot of cardio increases your cortisol, for example, which is a hormone that causes your body to store fat.

Here’s why the issue is important to me: When I started teaching I experienced a blissful, glorious period of leanness. I’m not talking lean like a piece of beef jerky.  But lean like you could see my ab muscles.  And then… my leanness vanished. And you could see my cute little belly pooch but no ab muscles. Between you and me, I preferred the ab muscles.

As a good fitness professional, I stay abreast of new fitness programs and my Time of the Belly Pooch coincided with reading books by peeps like Rachel Cosgrove wherein steady-state cardio in the form of running and group exercise classes are discouraged. And I started getting a bit of a complex.  Maybe I was getting pudgey because I was doing TOO MUCH CARDIO???

I’m not a scientist, I’ve told you this before. I got D’s in Bio 5A before I switched to Humanities. True story! But I am a professional skeptic and my logic muscles are in pretty good shape, so let’s look closer at CAIS.

CAIS sounds like a medical problem, but it’s not an actual diagnosable disorder. Another problem: “chubby” and “chunky” are relative terms. If you Google “Chunky (or chubby) exercise instructor syndrome,” you will likely wind up on bodybuilding forums.  Bodybuilders have a different standard of fat acceptability than the general public might have.  Here’s one excerpt from a forum:

“I have yet to meet a cardio instructor who is ripped. Sure they are in shape, endurance wise, but they don’t sport a very good six pack. If cardio is the key to burning fat, then how come aerobic instructors don’t have lower body fat percentages” (emphasis added).

Now, I’m not hating on the person who wrote this comment. I’m using this to illustrate that, to a bodybuilder, absence of a “very good six pack” indicates an unacceptably high level of body fat. In other words, chunkiness or chubbiness.  I like six packs as much as the next girl but I’m a bit reluctant to make them a standard of beauty or health. Did Elizabeth Taylor have a six pack? Marilyn Monroe? Does Kate Winslet? What about Shakira or Beyonce?  These are some of the flyest chicks out there and their little tummies are pretty much six-pack free. Are they chubby? Really? (Please be saying “no” in your head right now).

Here’s a post from Casey Ho over at Blogilates with examples of what the female body looks like at varying levels of body fat. Most of us, I think, would be pleased as punch with a body like the 18% – 20% examples. They don’t have six packs. The six pack appears in the 15% body fat range.  An oft-repeated statistic among bodybuilders is that the average female aerobics instructor has 18% body fat while average female competitive weightlifters have 16% body fat. I can’t find the original IDEA article quoted, but this statistic shows up a lot. For my post, I found the stat here.

Ah ha! So yes, aerobics instructors on average are chubbier than the average female competitive weightlifter. But take another look at Casey’s link showing different body fat percentages. I’m totally okay with the 18-20% range. I’ll be honest, my body fat is higher than that. Sorry Team Aerobics, I’m skewing our average higher.  I’m okay with not having 16% body fat. What I’m not okay with is labeling women who aren’t 16% body fat as chubby. It takes an extremely strict diet and training plan to achieve 16% body fat. While I have nothing but admiration for people who achieve those goals, I think that it’s important to keep in mind that those goals aren’t shared by everyone. 

So now that we’ve addressed the terminology issue, I wanted to quickly touch on some other problems with the CAIS:

  • Most trainers will tell you that your body composition is 80% diet related. The rest is your training and genetics. This contradicts the CAIS theory that one will chunk out simply by going cardio-crazy.  Almost every trainer that counsels against excessive cardio will also encourage an eating plan that eliminates processed food, provides 5-6 small meals a day and combines adequate protein, vegetables, fruit and complex carbohydrates.  This is significant.  I think a lot of aerobics instructors eat this way, but not all do. I try to but I really hate chicken breasts and protein powder and I really love cupcakes and wine. Diet variation between fitness instructors and bodybuilders is something that needs consideration.

If you’re a group ex student, this is something for you to keep in mind when choosing a fitness program. Is it a magical exercise that’s changing your body or a healthy eating plan? I have seen bodybuilders, dancers, Pilates instructors, yoga teachers and swimmers with beautiful bodies. They all train differently but a healthy diet is their common denominator.

  • Women are built differently than men. Surprise! In case you didn’t know lady bodies are different than boy bodies.  Women have higher body fat percentages than men. And although women come in different shapes and sizes, our lady hormones typically mean that we put fat on in different places than men.  As in our thighs and our bums.  So it’s funny to me to read statements (from men) about how women who do aerobics store fat in their butts and thighs. Really? Aerobics makes women store fat in their butts and thighs?  I guess my estrogen is off the hook. So I’ll quit with the aerobics and get skinny legs? News flash: If you think my ass and thighs are fat now, you should have seen them before I started teaching aerobics. (Photo source)

    Not my ass. Or thighs. For illustrative purposes only.

  • Your body adjusts the demands you place on it. I may have burned 400 calories in a Zumba class a year ago. Now, I may only burn 320 calories because mybody has grown stronger and more capable of handling the Zumba moves. That’s a GOOD thing! But the reduced calorie burn is important because:
  • Calories always count even when you teach fitness every day.  In my case, the real culprit to my belly pooch was eating too much.  I worked hard, sure. But eventually, the work was not as hard as it used to be and I burned fewer calories than when I began teaching.  Once I started logging my meals, I noticed that I was grabbing a lot of fast snacks (like granola bars) and eating additional treats after teaching class.  I was overeating by about 500-800 calories a day.  Friends, believe me: No workout in the world is going to save you from your fat cells if you eat more than you burn.

This post is getting excessively long. Since a picture is worth a thousand words:

Marathoner Kara Goucher. Cardio's workin' for this girl!


Queen Chalene. Teaches cardio classes 7 days a week and films/rehearses for her cardio videos on top of that. Chubby? Um, no.

Summary: “Chubbiness” in aerobics instructors is used to discourage students from participating in group ex classes. First, I disagree that aerobics instructors are “chubby” simply because they have higher bodyfat than body builders.  Second, the reasoning is flawed. It goes something like this:  Aerobics instructors are “chubby.”  Aerobics instructors teach aerobics. Therefore, aerobics instructors are “chubby” because they teach aerobics. Logic fail!

I propose that we find a way to move our bodies that makes us happy. For me, it’s dance-based cardio classes. If you’re not getting good results, have an honest talk with yourself about your eating and training habits. Log your food for 3 weeks and pay attention to empty calories and mindless eating. Ask yourself if you are giving your workouts your 100% best effort.

Instructors, I’d love to get your comments about the CAIS.  Students, how are you progressing towards your goals? Are you close? Are you a cardio junkie or do you balance strength/cardio training?