he reckons stick to less carbohydrate rich foods and you will be able to go for a 3 hour ride without needing any supplementary food source.

I just listened to a podcast on IM Talk, interviewing a dietician, Bob Seebohar, about metabolic efficiency.

His message is to keep carbs low before and during training (and racing) sessions, in order to prevent any spike in blood sugars. The idea is that the body can efficiently burn fat, even during intensive sessions, as long as there is not an increase in insulin to counter it. Instead of carbo loading pre-race, and eating a big bowl of cereal pre-workout, and eating gels every half an hour during a workout, he reckons stick to less carbohydrate rich foods and you will be able to go for a 3 hour ride without needing any supplementary food source. And that you can increase your efficiency such that only 5-10% of your energy needs come from an external source.

Fascinating stuff, and may be something in it for those unable to drop weight, even when training. I'm a bit dark that only yesterday I placed another order for $140, 2 x 25 gel, and am thinking I may not need it.

Then again, maybe I will? Has anyone else heard the podcast or pursued this concept?

You could probably do this no matter your diet. How *hard* is that 3 hour ride?

If performance is a goal over a 3 hour event, you aren't going to have an optimal result without some carbohydrate. Also, I would be wary of any advice from someone claiming an insulin response to carbohydrate consumption during exercise.

For me where this topic starts to fall down is recovery.

Executing a 3 to 4 hour ride on minimal nutrition - could you repeat it again the next day?

I just listened to a podcast on IM Talk, interviewing a dietician, Bob Seebohar, about metabolic efficiency.

His message is to keep carbs low before and during training (and racing) sessions, in order to prevent any spike in blood sugars. The idea is that the body can efficiently burn fat, even during intensive sessions, as long as there is not an increase in insulin to counter it. Instead of carbo loading pre-race, and eating a big bowl of cereal pre-workout, and eating gels every half an hour during a workout, he reckons stick to less carbohydrate rich foods and you will be able to go for a 3 hour ride without needing any supplementary food source. And that you can increase your efficiency such that only 5-10% of your energy needs come from an external source.

Fascinating stuff, and may be something in it for those unable to drop weight, even when training. I'm a bit dark that only yesterday I placed another order for $140, 2 x 25 gel, and am thinking I may not need it.

Then again, maybe I will? Has anyone else heard the podcast or pursued this concept?

Whereas I am sure that we can train our bodies to burn fat more efficiently, I am also sure that fat burns in a sugar flame. Depleting your body of its sugar load will also hinder its fat metabolism, cause intensity to decrease while increasing fatigue, and delay recovery. As is my understanding.

. Just depends if you want to follow real science or just see what works....

I wouldn't try it if you paid me. If your an IM athlete, you have two main limiter's on race day. Durability and Fueling. Why spend weeks a year not eating on the rides and runs, then race day comes and you stuff your face all day long and end of walking most of the run. At that point how much fat you burn doesn't mean a thing!

The other problem with his theory is that he has no good data to back up any of these claims. Sure he has charts and graphs showing you "better fat burning" but where is the control group? I am almost certain that if you took a group of athletes who were training at the same intensity's as the non eater's after 12 weeks of nothing but aerobic training they would be pretty equal on the "fat burning" scale. I mean, thats the point, lots of aerobic volume to make you a better "fat burner" Not only that but I would bet the group that was able to eat was not only having better 2nd and 3rd workouts of the day they would also be overall healthier athletes.

Did your damn control groups eat fat while riding rollers with their hands behind their backs?

Did your damn control groups eat fat while riding rollers with their hands behind their backs?

I will reiterate. There are control groups, this is not a new concept.
http://www.ncbi.nlm.nih.gov/...e%20lm%20and%20lipid

You should see the cortisol markers from an under fueled training session. Not pretty.

Simple rule. Eat unprocessed carbs(food) outside of training and make sure to have a little bit of protein and a good bit of fat with meals.

Quinoa with a huge scoop of guac and eggs and bacon. Done.

I see that. But what I don't see is a study that say's it works in the real world, or is actually healthy.

In oder to train well you need to eat. Lets say you get a 1% "fitness" boost out of this then walk your way to a 4hr IM marathon, what good did it do you? Metabolic Efficiency is or should be pretty close to the bottom of the average age groupers list on things that will make them faster on race day.

Lets start by simply eating better on a day to day basis.

I would be wary of any advice from someone claiming an insulin response to carbohydrate consumption during exercise.

yeah, i just did a 3 hr ride yesterday, and was starting to think i must be an awesome athlete to be able to sustain without food... thanks for bringing me back down to Earth :( hahaha

Quinoa with a huge scoop of guac and eggs and bacon. Done.

I would say I have poor metabolic efficiency based on this.

I would say I have poor metabolic efficiency based on this. I would say I am too gel dependent. I took 19 of the same gel, same flavour, with no GI issues, in my last IM.

All this gel could not be good for anyone. In fact I feel a toothache coming on as I write this. I am going to use what I learned from the Bob interview to cut back. I plan to do my usual ride tomorrow with less gel. Times will probably be down initially, but by incorporating some of his concepts for training the body to become more effient at burning fat, I would hope to see the same times on my benchmark ride

The performance improvement comes from the weight loss caused by riding with no fuel and by being able to go further on less.

Not being so fat seems to have a positive effect on performance ;-)

From my experience if all your fluid is nutrition then you can only absorb water at the rate you are absorbing nutrition. I mix it up 1 bottle nutrition / 1 water/electrolytes that way I can drink more and get the remaining calories from gels/bars.

Know of any studies that show a performance benefit from this? I understand the theory, though I'm a sceptic - just curious if there is evidence that it works in practice.

Noakes talks about it at length in "lore of running" and tentatively suggests "fat loading" prior to "carbon loading". i do not have the volume with me now, so look it up.

Know of any studies that show a performance benefit from this? I understand the theory, though I'm a sceptic - just curious if there is evidence that it works in practice.

While you are obviously correct that you already have way more energy stored than you need, the reason to 'fat load' from what I read is that it will increase the enzymes used to burn that fat so you can burn the stores you have at a higher rate. I am not a nutritionist but this is what I read. Granted it could be wrong.

Exactly. I will expound by saying, the reason I have been posting the Pubmed links, and in particular the Louise Burke "Nail in the Coffin" editorial is because these matters have been extensively investigated by her and others for over 20 years. We can go back to the studies out of Costill and Hargreaves labs in the late 80s and early 90s as the start of this avenue of research specifically with regard to performance, and the follow up work of Burke and her collaborators after that. If anyone had a vested interest in the plausability of "fat loading" as an ergogenic approach, it was Louise Burke as she pursued it as a focused research agenda for about a decade. At the end of it, the conclusion she came up with is, ... there's nothing there. Yes, increasing the ingestion of fat will increase the oxidation of fat, but we've known that for near 100 years, or more (too bad Coggan isn't around anymore, it's in his latest book chapter), and the Randall Glucose-Fatty Acid cycle has been around since the mid-sixties. And yet, nobody has demonstrated a clear performance benefit to fat loading. OTOH, the evidence is overwhelming as to the benefits of carb loading, clear performance benefits. So, no scientific evidence supporting one case, and a wealth of scientific evidence supporting the other, which one will you take? I love lard as much as the next guy, but....... Further, another poster suggested performance of anything longer than a minute requires fat loading,.. but in fact, for efforts of less than 30 min in duration, fat loading will likely exhibit an ergolytic effect. Since work above ~ 70% VO2max cannot be supported without carbohydrates, if the athlete is glycogen depleted and fueled with fat, they will be limited to this intensity, or, in other words, efforts lower than FTP. Also, as Burke pointed out in her editorial, since the other side of the upregulation of fat oxidation coin is a down regulation of PDH, and reduced uptake of the products of glycolysis into the TCA cycle, even if glycogen levels are not depleted, performance at intensities above FTP will likely be inhibited. At this point, I've said my piece and will now Exit Stage Left.

I just listened to a podcast on IM Talk, interviewing a dietician, Bob Seebohar, about metabolic efficiency.

His message is to keep carbs low before and during training (and racing) sessions, in order to prevent any spike in blood sugars. The idea is that the body can efficiently burn fat, even during intensive sessions, as long as there is not an increase in insulin to counter it. Instead of carbo loading pre-race, and eating a big bowl of cereal pre-workout, and eating gels every half an hour during a workout, he reckons stick to less carbohydrate rich foods and you will be able to go for a 3 hour ride without needing any supplementary food source. And that you can increase your efficiency such that only 5-10% of your energy needs come from an external source.

Fascinating stuff, and may be something in it for those unable to drop weight, even when training. I'm a bit dark that only yesterday I placed another order for $140, 2 x 25 gel, and am thinking I may not need it.

Then again, maybe I will? Has anyone else heard the podcast or pursued this concept?

My brain thinks that if I use less oxygen for carbohydrate oxidation that would leave more oxygen for my muscles.

One thing I never see addressed is that fat needs more oxygen than carbohydrate to oxidize as fuel. My brain thinks that if I use less oxygen for carbohydrate oxidation that would leave more oxygen for my muscles.
Just something that I always thought about when I Did low carb training.

What would your muscles be doing with that extra oxygen?

Pretty simple, in competitive endurance sports you want to use as much carbs, as sustainable for the distance and as little fat as necessary.

Marathon:

You need about 3000 cal
Stored as carbs: about 2000 (but only 1600-1800 can be used, the body keeps some reserve)
Stored as fat: unlimited (practically for that purpose)
Uptake: very limited, maybe 200-400 total

So fat needs to contribute roughly 1/3 or 1000 cals. The trick is, to teach the body to burn 1/3 of calories from fat close to threshold. Kenian runners proved beyond any doubt, that this is possible on a high carb diet.

Do you (or does anyone) have data on how much of the ~2000 calories worth of muscle glycogen is stored in the leg muscles versus upper body? Just curious since muscle glycogen is "non-transferable" between muscles and only liver glycogen, a much more limited supply, is available to muscles that run low. It makes sense that there would be more glycogen stored in the lower body since there is more muscle mass there.