reposted from training forum

[nmk85roll]

I posted this in the training forum about cardio. No one seemed to have an answer and I think it's a REALLY good question, especially for everyone that is trying to cut up now. So, hopefully someone will be able to chime in.

"Everyone talks about getting there bpm to 70-75% of their max in order to burn fat efficiently. Anything higher than that is considered the cardio zone. Here's my question...

What exactly is happening to your heart and body when it's in the "fat burning zone" and the "cardio zone"? What's the difference between the two in regards to how your body uses energy? Thanks everyone."

[YellowJacket]

Its a big game of substrate utilization. The 'fat burning zone' is where you're more apt use fat oxidation as your means of fuel and when your heart rate exceeds the 'fat burning zone', you're potentially using glucose as your means of energy. As bodybuilders and masters of cardiovascular activity, we know we'd rather burn fat for energy as opposed to our glycogen stores.

[nmk85roll]

Simple and sweet. Thanks YJ. Do you have any links to some more scientific reasoning and research? I want to learn a little more about it. Thanks again.

[YellowJacket]

I have a plethora of articles & studies on this, I like HIIT training myself.. but Ill get back to you with some articles, etc.

[nmk85roll]

Thanks YJ, I appreciate your time!!!

[slowtwitch]

I like depleting gycogen levels by lifting before doing cardio; or doing on an empty stomach.

lactic acid buildup is a pretty sure indicator that you are too intense with the cardio. It shouldn't burn... You shouldn't be gasping for air like you just did a heavy set of squats.

Anything under 80% - some days less feels like more. The body changes everyday. Get a Polar heart monitor if your gym's machines don't have 'em.

Its still the most boring activity in the world... I'd rather watch grass grow Climbing stairs, riding bikes, walking treadmills and going nowhere... LOL