Why that Zumba Class Will Make you Fatter (Crash course in metabolism)

My name is Buddylee, I am a Certified Strength and Conditioning Coach with over 17 years in the fitness industry. I meet with countless gym goers each week whose sole or at the very least most time consuming plan to lose weight is to go to a Group Fitness Class. And I get it, intuitively it makes since, if I need to lose more calories than I consume in order to lose weight then why not have as much fun as I can doing just that?

Oh if only it were that simple...

Ever wonder why you never see a bunch of really skinny women taking a Zumba class or a bodypump class, even though they are burning 900-1100 calories an hour in some of these formats?

The answer....NOT ALL CALORIES ARE CREATED EQUAL

Your body primarily burns two types of things for fuel (Fats and sugars[carbs]). In order to lose fat you need to mobilize it, then metabolize it. Here is the tricky bit: sitting down reading this article right now you are burning 85-100% of your calories from FAT, which is awesome. However, as you may have guessed, you aren't burning very many total calories. As you get moving and your heart rate increases, so does your metabolization of energy sources. To simplify, its a mostly linear relationship: increase Heart Rate, calories increase with it. Yahtzee!

Not so fast, here is the rub. As your caloric rate increases, the % of those calories coming from Fat DECREASES exponentially. This means that by the time you have to take a breath in between your words while having a conversation in that Zumba Class, you have stopped using FAT as an energy source.

Then what am I using you ask? As I said earlier, we primarily only use two types of fuel and so the answer is... Sugar. Which at first glance doesn't sound so bad. Too much sugar in the blood causes diabetes and stores as Fat. Using it up should be nothing but a benefit. However, once the free glucose (sugar) in your blood stream is used up, your body starts using liver glycogen (stored sugar). We humans have about a 2 hour supply of this stuff. In fact our bodies are extremely fond of it, so much so that after we use it, our bodies go into a mode in which anything it can convert to sugar, it does. This converted sugar is stored as more liver glycogen. Because the body is focused on its liver glycogen, it has not done anything to target stored fat. What does that mean? NO FAT LOSS...Worse, it teaches your body to crave Carbs.

So what's the answer?

It's two fold:

1. If you want to do cardiovascular training, get out of those classes that have you burning 80-100% sugar and start doing Interval Training. As a basic starting point: 3 days a week on a treadmill at your normal walking pace and a 2% incline, then after a 5 min warm up, alternate your incline from 2 % to 6% every 2 mins. Repeat 5-10 times and cool down. This style of training will allow your body to learn how to burn more calories at a higher Fat %.

2. Start incorporating Strength Training into your routine. The break down and subsequent increase in lean tissue will give you a two fold benefit. A shorter term 12 hour EPOC, meaning more oxygen being used to burn more FAT, and a longer term increase in your metabolism as it maintains an increased lean body mass.

I hope you all have enjoyed this article. Please leave me a comment on what you think, any questions you may have or suggestions for future fitness related articles. Thanks.