Weight Loss Tracker

Thursday, November 19, 2009

The rule of the game: INTENSITY

Thanks to a friend of mine here, who directed me to the err of information I found, I looked further.  I LOVE Jillian from The Biggest Loser, and though she's not a doctor (that I know of), nobody can deny that she seems to know her stuff.  I just got this in my e-mail inbox which addresses low-intensity versus high-intensity workouts and working in the so-called fat-burning zone.  Here's what she says:

If you're looking to shed stubborn pounds, the rule of the game is to increase the intensity of your workouts. I want you to be working out at 85 percent of your maximum heart rate (MHR). However, you may have heard the "fat-burning zone" theory that encourages you to work out at just 70 to 75 percent of your MHR. The outdated assumption is that your body is drawing predominately on fat calories for energy — WRONG! It's completely misleading and it's time to lay the "fat-burning zone" myth to rest.

During physical training, your body has three possible sources of energy: carbs, fat, and protein. Protein is a last resort — of the three energy sources, your body is the most reluctant to draw on your protein stores.
Whether your body takes energy from glucose, which it gets from the breakdown of carbs, or fat depends on the intensity of your workout. Training at a high level of intensity forces your body to draw on carb calories for energy — they are a more efficient source of energy, and your body goes for its premium fuel when you're working hard. If you are training at a low level of intensity, your body doesn't need to be as efficient, so it will draw on a higher percentage of fat calories for fuel.

Sounds like low-intensity training would be more effective when it comes to losing fat, right? Wrong. These physiological facts are the ones that spawned the mistaken belief that low-intensity activity is better than high-intensity activity when it comes to burning fat and losing weight. These days we know that even though the ratio of fat-to-carb calories might be higher during low-intensity exercise, fewer calories are used up overall. High-intensity exercise burns the biggest number of calories.

From LOSING IT! With Jillian Michaels
Thursday, November 19, 2009


  1. Another great post! I find all this interesting but terribly conflicting and a bit confusing.. hard to know whos right and wrong.. and hey, look at that. I didn't know what you looked like and you have a slideshow up. How cool! You are looking good!!!

  2. Thanks, Cara! I hate my pictures still, but I just learned how to do this and was very excited. My bandiversary is Saturday, so I will take some new ones to add to it.

    And I agree... it IS very confusing. The first one I posted was written by a doctor, so I just took it at face value. But I have to say, Jillian has proven herself time and again. I have her book about jump starting your metabolism that I hope to read here shortly when classes end.

  3. I'm confused... so we are supposed to do a more intense work out for less time??? I am taking this as keep doing the tread mill for 30 minutes say and instead of changing to 45 mintues, stay at 30 but maybe put the incline up??? Is that what you are getting?

  4. I would say either do the same amount of time at a higher intensity, OR even doing a longer amount of time at the same intensity would give you prositive results.

    The way Jillian describes it, it's simple math. Calories expended (whether 30 minutes at a higher rate or 45 minutes at the same) will yield a higher caloric expenditure. Either one would increase your output.

    Sometimes when I haven't had the time to do an hour or more, I've done maybe 30-40 minutes but ramped up the intensity of the workout. I still feel that I've gotten a really good workout, and my GoWear Fit seems to show that I've done well.

  5. Another thing that I KNOW is good for results is to do interval training -- maybe take that 30 minutes and do every other five minutes at different intensities. The first maybe at a 0 incline, then the next five at a 10 and back and forth that way.