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Monday, July 26, 2010

Former Aerobics Instructor is Now anti-Cardio

I went to a Jazzercise class last week with some friends. Jazzercise is basically aerobics, but each song has its own choreography. It was a lot of fun, and quite similar to what I used to do as an aerobics instructor. But it was interesting listening to them, and doing all this cardio when... I don't believe in it.

Let me just say first of all, that moving your body is good. Doing jazzercise, or aerobics, or jogging does keep your heart pumping and makes you feel good. But for weight loss (the reason most people exercise), I believe cardio is the least effective form of exercise.
Here are the reasons why I no longer believe in cardio:

It's not as simple as "calories in, calories out."  The instructors at my class today reminded us of how many calories we were burning. ("One class can burn up to 600 calories, ladies!")  But scientific studies have shown that cardiovascular exercise makes you hungrier. Your body wants to replace those lost calories. Basically, with cardio, you are fighting your body to lose weight. Dr. Stephan Guyenet uses a great analogy that helped me to visualize this. (You can listen to the entire podcast here.)  He said that losing weight by doing cardio is like having the a/c on in your house. But when it gets too cool and you want to warm it up a bit, you open the front door. Well, you know what happens then, right? The air conditioner works hard to cool the house, requiring more energy. With cardio, you are burning more calories (working harder), so your body will crave more calories for energy too.
If "calories in, calories out" worked, then you would exercise (calories out) and eat less (calories in). But that is missing one very simple physiological process: hunger. You can only fight your body's hunger signals for so long.

Cardio can do harm to joints and cause overuse injuries. During the weight portion of the class, we worked very specific small muscle groups over and over and over. Jumping and running definitely have their place in an exercise regimen, but all you have to do is look at the number of runners with bad knees to know that overuse injuries occur. Often.

Your body adapts to cardio. This means that doing the same exercise becomes less effective over time. Your body adapts to the exercise--  that's why it gets easier. Your body is becoming more efficient at the exercise. Good for the body, but bad for weight loss. That means that to do exactly the same exercise, you will be burning less calories after a month than you were when you started.

So maybe you know someone who started doing cardiovascular exercise and lost a lot of weight. Maybe you know a lot of people who have done that. But what if it wasn't the exercise at all?  What if, like my instructor said today, "after I've done a class, I don't want to go eat that cheeseburger. I worked so hard to burn those calories, I don't want to put them back in."  Maybe cardio exercise changes our psyche more than our figure, causing us to make other changes, like in what we eat. Or maybe, when we start working out, we are burning so many calories that our body has a hard time replacing them all through food. But as time goes on, and our bodies adapt, we burn less calories and our exercise is less effective at helping us lose weight.

Coming up: In my next post I will detail what I believe in instead of cardio and how to work with your body to lose weight.


  1. I'm excited for the next post!

  2. I totally agree.... I was teaching 24 aerobics classes a week and not losing a pound because I have been doing it for a long time. Even though the classes were varied the intensity collectively for each week must have been th same. People in my classes were in awe that never lost weight because I am the energizer bunny! I am also a dancer with the characteristic bottom half as well. I am also a personal trainer and feel so strongly that weights are the answer.

  3. Great points! I've been thinking along these lines for a while, but I was wondering if I was just being lazy and trying to find an excuse to excuse it :o)

  4. I'm a firm believer in your post. I don't look like a picture but I am fit and that comes from a variety of weight training and simple pushups, situps, and walks at home. My weight dropped drastically when I started lifting and then has stayed very constant since then.

  5. Cardio is definitely over rated! There are much simpler ways of losing weight and staying fit. :-)

  6. Was just talking about cardio vs. other forms of exercise tonight with my where's that "next post" for the answer? ;) Katie

  7. I've heard this before and I'm relieved because cardio sucks for me. I'm border-line asthmatic (according to my allergist) which makes doing cardio very hard for me since I start wheezing. I can't wait to read the follow up!

  8. @ Katie and Kathie, the first post is up! And more coming soon...

  9. cardio is over used. There's a lot of things to lose fats and regain your confidence again

  10. Amazing post!Its really excellent information. You definitely have a great post over here! There is a lot of information on this post.Thanks for posting this informative article.


  11. Don't agree. I've seen far too many people who look great from simple regular running. I do agree that strength training must be included to balance things out. But the anti-cardio trend has gone too far in my opinion. Everybody is different. For some, cardio might be ineffective. But that doesn't mean it applies to everybody.

  12. I agree, as it pertains to what my experience has been like. Cardio became like an addiction for me. I would go at it for an hour or hour and a half because it felt so good. But I also found that it was draining energy away from other passions.
    And it make my boobs shrink ;P
    I have found that living a full, active life (walking, horsing around, just pursuing other activities) plus lifting weights has really been the perfect formula for me. I am proud of my strength, am pleased with the results, and most of all, I STILL HAVE A LIFE!!! 20-30 minute weight training session 3 times a week, eating in moderation, is good for me.
    It keeps me in balance and I like the challenge of tackling heavier weights.