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Fat Oxidation

Posted: Thu Jun 14, 2012 10:35 pm
by TimG
I recently completed a 3-hour Fitness Assessment that included Body Composition, Muscular Strength and Endurance, Aerobic Capacity (VO2) with ECG, and Flexibility testing. The testing was done at a facility that uses state-of-the-art testing equipment, so I am confident that the results are meaningful. One result that troubled me some was that I have very low fat oxidation (only 1 KCal/min) in the optimal fat-burning aerobic exercise zone. The exercise physiologist said that keeping my cardio workouts in the optimal fat-burning zone (about 65% to 70% of maximum heart rate) will actually increase the fat oxidation rate over time.

What is your opinion about this? Also, what kind of strength training workout would help fat oxidation, or does it matter? If I haven't provided enough information for you to answer my question, please let me know. Thanks!

Tim

Re: Fat Oxidation

Posted: Fri Jun 15, 2012 4:13 am
by Jungledoc
Sounds suspect to me. How was fat oxidation measured?

Just cause someone has fancy equipment doesn't meant that the tests they are doing have any validity.

How much did the assessment cost?

Re: Fat Oxidation

Posted: Fri Jun 15, 2012 10:47 am
by TimG
Jungledoc--

The test was an aerobic capacity direct V02/Gas Exchange on a bike ergometer. There was also a test of Resting Metabolic Rate using a mask to measure gas exchange. I'm not sure how those results were used calculate the fat oxidation during different aerobic exercise zones. The cost was $385 and was done at a fitness company in Seattle called PotentRx (http://www.potentrx.com" onclick="window.open(this.href);return false;)

Re: Fat Oxidation

Posted: Fri Jun 15, 2012 11:32 am
by robertscott
It strikes me that the important question is: are you fat?

If the answer to that is "no" then their results are probably BS.

Re: Fat Oxidation

Posted: Fri Jun 15, 2012 11:46 am
by TimG
Robert--My weight is normal

Re: Fat Oxidation

Posted: Fri Jun 15, 2012 11:55 am
by robertscott
there you go then, I wouldn't give it a second thought

Re: Fat Oxidation

Posted: Fri Jun 15, 2012 2:17 pm
by jlmoss
But what are your goals?

Be strong, wanna be a marathoner, wanna be a sprinter, crossfitter?

You mentioned something about strength training... I'm not sure fat oxidation is all that important where strength training goals come into play is it?

I may be pretty ignorant in this subject, but isn't fat oxidation key for marathoning and stuff like that?

Re: Fat Oxidation

Posted: Fri Jun 15, 2012 3:10 pm
by TimG
J L Moss--

My goal is general fitness, so I do cardio workouts, lift weights three times a week (free weights), along with flexibility and core exercises. I am also trying to raise my HDL level, which is low. I'm 63 and in good health.

What I've read from reliable resources, including ACSM literature, is that aerobic exercise in the optimal fat-burning zone (65% to 70%) of your maximum heart rate (one of the reasons I had the testing done), will help raise the HDL level. As I understand it, in this zone, there is an increase in enzymes that break down triglycerides, resulting in a greater conversion of cholesterol to the form of HDL.

Re: Fat Oxidation

Posted: Fri Jun 15, 2012 3:30 pm
by stuward
Triglycerides are raised by too many carbs. If you want to improve them, cut down the carbs.

HDLs are raised by infections. Runners often have high HDLs because their chronic cardio makes them more subject to infection.

Here's a better approach.

http://perfecthealthdiet.com/2011/04/how-to-raise-hdl/" onclick="window.open(this.href);return false;
HDL can be raised in destructive ways – such as ingestion of toxins or pathogens – but there are healthy ways to raise HDL.

I believe the following four ways are healthiest, and are sufficient to optimize HDL levels:

Eat a nourishing diet rich in saturated and monounsaturated fat, especially dairy fat, but low in omega-6 fats, fructose, and other toxins. In short: eat the Perfect Health Diet.
Be physically active. Be on your feet as much as possible; favor a standing desk over sitting. Do resistance exercise or other intense exercise occasionally.
Engage in intermittent fasting, and consume a lot of coconut oil, coconut milk, or MCTs to stimulate the ketone receptor.
Drink alcoholic beverages – but only when consuming meals low in polyunsaturated fats. Drink up when you eat beef, but be cautious when the entrée is salmon.
Niacin, the most effective pharmaceutical for raising HDL, has some toxicity and is probably inferior to coconut oil and intermittent fasting except in people with protozoal or fungal infections.
This isn't really contradictory to the ACSM recommendations (even if I doubt the mechanism in the ASCM recommendation) in that a moderate walking program is recommended vs a more intense program. Walk and stand a lot but keep up the resistance training. Brisk walking or intense sprinting have benefits but I don't see any evidence that there is any need to do the in-between stuff, like jogging or running.

Re: Fat Oxidation

Posted: Fri Jun 15, 2012 7:02 pm
by TimG
Stuward,

Wow, there is a lot to digest in the article you linked to. Thanks for providing a summary. I have never heard of high HDL caused by toxins or infections. Well, there's plenty to consider in the author's point of view, which seems to be somewhat unorthodox.

Recent studies have shown that moving around a lot is good for you--as opposed to sedentary athletes and couch potatoes.

Re: Fat Oxidation

Posted: Mon Jun 18, 2012 6:26 am
by josh60
TimG wrote: What I've read from reliable resources... is that aerobic exercise in the optimal fat-burning zone (65% to 70%) of your maximum heart rate ... will help raise the HDL level.
I guess one person's experience doesn't mean much, but I'm 61 YO and my HDL went up considerably (from low 40's to 62) by doing cardio at a higher HR than that. Usually I stay at 85%-90% of my max HR for most of the time I'm exercising. You should also remember your real max HR is not the one you get from the famous formula (220 minus age) but has to be determined individually, and some testers are in too much of a hurry to measure it correctly. When I did my ergo test they didn't let me build it slowly enough to get to the right number, but I knew they were wrong because I had reached higher numbers while exercising (power walking on an incline, building speed slowly to my maximum speed and keeping at it until I couldn't continue, taking the HR reading right there. This test carries a risk factor at our age, so I don't recommend it).

Anyway, for me the numbers are:

- By formula: 159
- By the ergo tester: 168
- By my body: 176

Re: Fat Oxidation

Posted: Mon Jun 18, 2012 7:16 am
by stuward
Josh, your experience underscores what I was trying to say, that lots of low intensity general activity coupled with brief high intensity periods provide the best results. That "low intensity general activity" is what some people call exercise. I call it, get off your ass and start moving. You don't have to think about it, it just becomes a habit to walk to where you need to go. This is what I think ACSM is referring to in their recommendations, and the 65% rate is consistant with a brisk walk. If you're younger, that might translate to a jog. Either way, it's just activity, not exercise.

What you and I call exercise is that higher intensity work. This is what is missing in most "cardio bunny" programs. You need both. The moderate level (70-85%) stuff is only useful in that it helps you get to the high intensity (85-90%) level. The other peice that's missing is the recovery. Doing moderate cardio every day just wears you down until you get sick or injured and are forced to take a break.

Re: Fat Oxidation

Posted: Mon Jun 18, 2012 8:23 am
by Kenny Croxdale
TimG wrote:J L Moss--

My goal is general fitness, so I do cardio workouts, lift weights three times a week (free weights), along with flexibility and core exercises. I am also trying to raise my HDL level, which is low. I'm 63 and in good health.
Raising HDL

1) Aerobic Exercise raises HDL, especially High Intensity Interval Training as Josh60 and Stuward noted.

2) Saturated Fats raise HDL. They also increase LDL readings. However, saturated fats increase the benign Particle A LDLs not the bad Particle B LDLs.

All fatty acids elevated HDL cholesterol when substituted for carbohydrates, but the effect diminished with increasing unsaturation of the fatty acids. http://www.ncbi.nlm.nih.gov/pubmed/1386252" onclick="window.open(this.href);return false;

As Stuward basically stated, simple (high glycemic index) carbohydrates are usually the factor that elevate Particle B LDLs.

What I've read from reliable resources, including ACSM literature, is that aerobic exercise in the optimal fat-burning zone (65% to 70%) of your maximum heart rate (one of the reasons I had the testing done), will help raise the HDL level. As I understand it, in this zone, there is an increase in enzymes that break down triglycerides, resulting in a greater conversion of cholesterol to the form of HDL.
Aerobic exercise in general increases HDL levels.

Fat Buring Zone 65-70%

The lower the level of activity, the greater the PERCENTAGE of body fat burned. Thus, the greatest PERCENTAGE of body fat burned is during sleep.

Excess Post Oxygen Consumption, EPOC

The greatest amount of body fat is burned when the body is pushed beyond "the fat burning zone", as Josh60 does (85-90% of Heart Rate Max).

EPOC dramatically increase you metabolism. So, you end up burning body for hours after your workout is over.

Forget The Fat Burning Zone Clarance Bass
http://www.cbass.com/FATBURN.HTM" onclick="window.open(this.href);return false;

Research shows that you can burn up to 9 time more body fat with High Intensity Interval Training, which cause EPOC vs low level aerobics with 65-70% of your Heart Rate Max.

Anerobic Excess Post Oxyen Consumption Methods

Anerobic weight training program can produce the same EPOC effect. As with High Intensity Interval Training Aerobics, work set need to be intense. That means driving your heart rate above 75% of Heart Rate Max.

You weight training rest periods need to be short, 30-60 seconds.

Circuit Weight Training would provide you with the EPCO effect.

Body Composition
"Body composition provides an accurate measure of fat and lean mass..."
http://www.potentrx.com" onclick="window.open(this.href);return false;)

Overall this company look impressive. However, body composition measurements are anything but "accurate".

At best body composition measurements are a "Ball Park" reading. That why they ALL will tell you there is a plus or minus factor involved.

In other words, they are guessing at your body fat percentage.

Skin Fold Measurements
http://www.formulamedical.com/formula%2 ... infold.htm" onclick="window.open(this.href);return false;

"Most equations are accurate in the range of 4-5% and the actual reading can be plus or minus 10% of your real fat."

4-5% Difference

That means if you weigh 170 lbs and the measurement was off 4% , you have either 6.8 pounds more fat or 6.8 pound more muscle. A 6.8 pound difference is a big ball park to be in.

Kenny Croxdale

Re: Fat Oxidation

Posted: Mon Jun 18, 2012 9:36 pm
by TimG
I appreciate your expert opinions and the additional helpful comments, information and studies. I understand, too, the body composition measurements are not exact. Maybe they'll perfect DEXA scans (used for bone density) in a way that provides more accurate body composition. (The price is prohibitively high). I agree from a number of fitness research studies I've read, that HIIT gives you a lot of bang for your buck. I am trying to combine various exercise modes in ways that give the best results. I know that thousands of aerobic exercisers don't lift weights, which doesn't make any sense, because while your heart is in good shape and perhaps muscles in your legs associated with running, you're not building important muscle mass over the entire body. Even the father of aerobics himself, Kenneth Cooper, realized this a number of years ago and modified his recommendations to include strength training. Thanks to everyone who has posted a response.

Re: Fat Oxidation

Posted: Sun Jun 24, 2012 8:42 am
by Jungledoc
I actually didn't think that anyone believed in a "fat burning zone" any more!