Fat-burning during workouts

What do you make of this comment (taken from a book I bought at Costco -101 Fat-Burning Workouts & Diet Strategies). Preparation for cardio workouts:

'If your main cardio goal is to burn fat - lots of it - then avoid carbs altogether. Multiple research studies show that when you don't eat carbs before aerobic exercise, more bodyfat is burned. But that doesn't mean you should run on an empty stomach. Japanese researchers reported in the journal Perception and Motor Skills that when athletes consume only amino acids before aerobic exercise, they burn even more fat than when they drink water alone. Reach for snacks that deliver about 5-10 grams of fast-digesting protein (they suggest either a scoop of whey protein in water, 2 hard boiled egg whites, turkey or chicken breast, or canned light tuna).'

Thought or experience with this?

Any diet advice that eliminates an entire macronutrient is not healthy in my opinion.

I know from personal experience carbs do nothing for me. Protein is a much better option for me. I think it is a body by body need.

I'd like to see those studies. I think there are other variables to consider, too. Is it a morning workout (when you've likely depleted your stored glycogen overnight) versus an afternoon or evening workout when you might still have some stored glycogen from whatever you've ingested during the day? How long and/intense is the workout? What I need to eat before a hour-long spin class is different than what I need for a multi-hour ride. I also think studies suggest that men and women burn fuel sources somewhat differently (I'm recalling a study I read about discussing how men and women process energy drinks consumed during exercise).

Like redrhodie, I'm suspicious of the advice. I'm no expert, but my gut tells that it's a simplistic take on how our bodies fuel aerobic exercise.

I eat lots of carbs. Waffles everyday for breakfast, sandwich or pasta at lunch, baked potato or pasta for dinner most nights. I've lost plenty of fat on this diet.

Studies have shown that eating before morning exercise helps you work out longer and at greater intensity, so you burn more calories. And that is how you lose fat.

Your body digests carbs faster than it digests protein or fat. So having just protein before exercise means you're more likely to have GI problems from undigested food.

If you want to buy a book, buy Nancy Clark's Sports Nutrition Guidebook. She is a registered dietitian who focuses on athletes.

Okay, I know someone will be able to find this . . . It wasn't that long ago someone posted an article about how men and women burn energy differently. And it said something along the lines that women don't need to carbo-load like men do. And that women should stick to lean proteins . . .

Anybody else remember this?

I remember what you're talking about Limewave but my recollection of what it said was somewhat different...

I'm remembering it said that women can't carbo-load in advance the same as men, so we need to consume more carbs during a long effort.

Hopefully someone will find what it actually said. ;)

But generally, I concur with the idea that it's dangerous to eliminate an entire macro-nutrient. Back in the 70s and early 80s it was "you don't need protein"... then in the late 80s and early 90s it was "you don't need fats"... and then Atkins and South Beach. All of it, without exception - even the macrobiotic craze of the 80s IMO - is marketing-driven.

Article doesn't talk specifically on carbs.

Yes, it was cited here..from Canada :D
http://forums.teamestrogen.com/showt...burn+faster%22

Remember, oatmeal has carbs..and it's recommended as an easy to burn good carb before a workout.

That one's relevant, but there was another one that had to do specifically with carb-loading before a big event.

Here's a meta-analysis, but it's a couple of years old: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2129154/

I'll keep looking...


Edit again: here's the article we were discussing earlier. It's a layperson's summary of two studies. Both pretty much reach the same conclusion (the one I remembered ;) ).

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Originally Posted by OakLeaf

I remember what you're talking about Limewave but my recollection of what it said was somewhat different...

I'm remembering it said that women can't carbo-load in advance the same as men, so we need to consume more carbs during a long effort.

Hopefully someone will find what it actually said. ;)

But generally, I concur with the idea that it's dangerous to eliminate an entire macro-nutrient. Back in the 70s and early 80s it was "you don't need protein"... then in the late 80s and early 90s it was "you don't need fats"... and then Atkins and South Beach. All of it, without exception - even the macrobiotic craze of the 80s IMO - is marketing-driven.

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You're probably right. I'm notorious for getting the details wrong :)

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Originally Posted by ny biker

I eat lots of carbs. Waffles everyday for breakfast, sandwich or pasta at lunch, baked potato or pasta for dinner most nights. I've lost plenty of fat on this diet.

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Me too. Well, maybe not that much but close. :)

I visit another health and fitness forum where a lot of the people there are really into weightlifting, and they constantly promote protein protein protein, all the while singing the evils of carbs. Admittedly I did notice a difference in satiety when I increased my protein and was more conscious of my intake in general, but I personally had HORRIBLE luck trying low-carb. It had a really negative impact on my cycling.

I've read that success with one vs. the other has to do with insulin resistance levels in the body, which vary by person.

I think the original quote was about what to eat before exercise, not cutting out carbs altogether. I'm sceptical too, aren''t carbs the body's preferred and first form of fuel? But I have been told that you can sort of wean yourself over to using more protein and fat instead, but I think this takes some getting used to.

But this one I'm pretty certain of: "fat-burning workouts" are largely a misunderstanding. As I recall, studies showed that low- and medium-intensity workouts burn more fat than high-intensity workouts during the workout. But in total, considering the muscle you build, and the after-effects of the exercise, high-intensity workouts were just as useful for burning fat, it was the total effort (calories out) that counted.

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Originally Posted by lph

But this one I'm pretty certain of: "fat-burning workouts" are largely a misunderstanding. As I recall, studies showed that low- and medium-intensity workouts burn more fat than high-intensity workouts during the workout. But in total, considering the muscle you build, and the after-effects of the exercise, high-intensity workouts were just as useful for burning fat, it was the total effort (calories out) that counted.

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You're right, I think they call it the EPOC effect or something like this. The shorter, high intensity workouts create a significant 'afterburn', plus are touted to have the added benefit of protecting muscle mass better. But I've read that there are benefits to both short high intensity and longer low/medium intensity. I use this to justify my 1.5-2 hour rides, anyway. :)

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Originally Posted by lph

high-intensity workouts were just as useful for burning fat, it was the total effort (calories out) that counted.

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True, but by definition it's much easier to sustain a lower intensity. Most people can ride a bicycle all day long at 60-70% of MHR. Start getting up near 90-95% and you're talking half an hour or 45 minutes for all but the most highly trained athletes. A ride of moderate length and intensity will always burn more calories than an interval workout or just going out and hammering for a very short time.

Quote:

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Originally Posted by OakLeaf

True, but by definition it's much easier to sustain a lower intensity. Most people can ride a bicycle all day long at 60-70% of MHR. Start getting up near 90-95% and you're talking half an hour or 45 minutes for all but the most highly trained athletes. A ride of moderate length and intensity will always burn more calories than an interval workout or just going out and hammering for a very short time.

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Interesting take. My trainer presented it to me in a different way: if you're going to do cardio for an hour, you'll burn more calories overall (and more fat calories) if you do intervals/high intensity for that hour than if you do low intensity exercise.

People might be physically capable of exercising for a longer period if the intensity is lower, but you need to have time in your schedule for it.