I’ve tried it in training, it’s horrible. I’m not after an argument, I was genuinely surprised you said you were gagging for a gel so early. Sorry! I’m sceptical of the 45 min thing because nobody in the outside world seems to have heard of it. I remain open-minded and ready to be convinced, but at this moment I think the dossier’s been sexed up.

Well I’ve always taken on lots of carbs, and I’ve always tended to eat lots of carbs generally, so I think my body was (and still is) conditioned to use them and bad at burning fat. Which is why I think I have had good results doing this – I’m bad at it to begin with so that kind of training makes a big difference.

I also think that my physiology is biased towards burning carbs, lots of Type II muscle I think. This may be why I have a tendency to eat lots of carbs, but that may in turn because I have a tendency to sprint a lot anyway, because I enjoy it.

I got the piss ripped out of me last time this came up, for thinking I’m special, but I think Type II people are in the minoroty in MTBing and amateur road cycling, and a lot of training and diet advice is aimed at Type I people.

Well I don’t know if there’s any difference between people biased towards Type I and II, but we’re all very very inclined towards burning carbohydrates, fat is simply a poor source of energy.

we’re all very very inclined towards burning carbohydrates

Not sure that’s true. Our bodies generally prefer fat because even skinny people have way more of it than carbs.

Then there are many people who’ll ride all day with nothing but a banana in their jersey pocket. It’s come up on here before, it’s pretty split between people who get ravenous and eat on relatively short rides, and those who just don’t care.

I think there are big differences between people and muscle fibres are just one.

Mol, muscle fibre types aren’t fixed. The longer you do something there more they will adapt. So if you are mostly type 2 but have been doing endurance sports for years, it’s likely your physiology would have changed

An obvious case is Sir brad of wiggins, gone from track sprinter to 3 week roadie in the space of 3-4 years

This has been very helpful, thanks for the responses and thanks in particular to Molgrips for confirming my reading.

I was ONLY interested in the science behind the idea and in understanding it. I haven’t been able to find any scientific references to the idea of clean and dirty carbs so my understanding was gleamed from my own reading and desperately thinking back to A-Level biology (which I wasn’t very good at when I did it 24 years ago!)

I’ve had a lot of success losing weight myself this year and since Jan 1st the count is now at 13kg, achieved simply by eating less and definitely eating less carbs. But then I started out at 108.5kg so really there was a lot to lose and it may be that I need to get cannier the further down I go.

Molgrips do you also know anything about actively trying to manage blood PH as a way of also managing fat burning and fat deposits. That was something else that got my BS radar going (although I now see that there is something physiological in the clean dirty carbs thing).

One other interesting point is that the difference between clean and dirty carbs doesn’t

Our bodies generally prefer fat because even skinny people have way more of it than carbs.

That’s simply not true. ‘The primary function of carbohydrates is to supply energy for cellular work’ [Exercise Physiology, McKardle, Katch & Katch]. Basic.

Moley’s advice is confused. Why would we need to train ourselves to use fats – a poor source of energy, requiring far more oxygen to metabolise than CHO – if indeed it were the preferred energy source?

I admire the mole’s enthusiasm, but you need to understand some of the basics before doling out well-meaning advice. I’m a long way from an expert, but I fear he’s further 🙂

sorry for the hijack, but is there a difference in:
1 – the ability of the body to shift fats created from excess carbs, compared to ingested fats
2 – where the two different types are stored?

molgrips – Member
Our bodies generally prefer fat because even skinny people have way more of it than carbs.

stever – Member
That’s simply not true.

That skinny (and fat) people have larger reserves of fat than glycogen is true.

Plus there’s a higher concentration of calories per kg of fat.

Fat stores have around 8000 calories per kg, glycogen stores around 4000.

I thought that the body would tend towards metabolising protein, i.e. muscle tissue, in the absence of glycogen.

I know that you can end up losing muscle mass my going too extreme in your dieting, but never really understood how that balances against reductions in body fat, which clearly also happens.

I’ve also heard/been taught that fat metabolism arising from exercise only starts to happen a certain period of time into the exercise. Molgrips is that the 45 minute figure you were referring to?

That skinny (and fat) people have larger reserves of fat than glycogen is true. Plus there’s a higher concentration of calories per kg of fat.

True, but not pertinent. Fat has greater energy density, but gives it up more reluctantly. Even the 9st, 10% body fat waifs have 50,000 kcalories of the stuff stored up – doesn’t mean they can mobilise it very easily.

I am trying to lose weight at the moment and seem to be having some success with eating less and training more, however with a sample size of one and with the subject being aware of the terms of the study, I think my results may show some bias

Add another one to the sample size. We’re still statistically insignificant. It’s taken 3 months for my weight loss to become more regular with extra exercise. I suspect that this may be age related more than anything.

The body doesn’t pick one source and only use that.

As exercise intensity levels rise the amount of energy derived from glycogen stores will increase to be the higher percentage. This is as it’s more efficient than fat conversion.

This does not mean you stop burning fat just the ration shifts towards glycogen.

To truly burn fat only, you need to first empty your glycogen stores. This is why training on empty i.e. in the morning on no breakfast, is good for this.

If you’re losing muscle mass through dieting, you must be continually in some serious calorie deficit.

Why would we need to train ourselves to use fats – a poor source of energy, requiring far more oxygen to metabolise than CHO – if indeed it were the preferred energy source?

Because it’s more plentiful. As far as I know, it’s basic old-school physiology – your body burns fat until the point where it can’t get enough oxygen to the muscles to burn enough to provide the energy you’re asking for, at that point it starts using the glycogen.

It makes sense if you think about it. Ride slowly, dont’ eat much, ride all day. Ride fast, don’t eat much, bonk.

I’ve also heard/been taught that fat metabolism arising from exercise only starts to happen a certain period of time into the exercise. Molgrips is that the 45 minute figure you were referring to?

Not sure.. maybe.

I got the piss ripped out of me last time this came up, for thinking I’m special,

With good reason, IMO.

The difference between you and your next door neighbour in physiological terms is next to nothing, and claiming that you are different and therefore need to eat differently is hard to reconcile.

I have a tendency to sprint a lot anyway

,

What does this mean? Anyone who has ridden a bike competitively can ‘sprint’, some are better at it than others, but it’s not a biological speciality.

I’m sure there is substance to some of your claims, but I’m equally sure that you do over-egg the pudding when this particular subject is raised.

As for the ‘ride lots without taking on much nutrition’; that’s me, that is.

…but only because I’ve trained myself to do it over the years. Compare me to those who suggest they can’t manage 3 hours without 3 litres of water and food, and wonder how we, as a species, ever got to go anywhere…

As I say, I’m not rubbishing what you say, but I do think your exaggeration does little to support it.

Two pages already!

Without references, my eat less and train more is just as valid a conclusion as the wait 45 mins stuff. Both based on individual accounts, that are bound to be biased. Admittedly I don’t claim any authority on the subject, but authority is the weakest form of evidence. The science would require data which has been subjected to independent scrutiny, kind of like the stuff you find written in journals which people can then reference.

I’ve also heard some stuff about delaying eating on longer endurance stuff (2h+) as a way to encourage the fat burning mechanism to kick in earlier. Reference please?

I had a look when you were asking on RW, but couldn’t find it. I do recollect reading it, and my gut reaction is that it was like a lot of these studies. Too small, and too big a conclusion extrapolated from the results. I used to subscribe to a mailing list that began to obsess about these sort of dietary studies. Anything that gave results that didn’t concur with the group think was lambasted, anything that reinforced it was deemed perfect research.
One thing I did take away from the group was that if you were to generate a scatter graph of number of posts on the performance benefits of a diet by an individual vs. actual performance of same individual you’d come to the conclusion it wasn’t something worth worrying about 🙂

Anyone who has ridden a bike competitively can ‘sprint’, some are better at it than others, but it’s not a biological speciality.

That is dead wrong. It IS a biological speciality.

The difference between you and your next door neighbour in physiological terms is next to nothing

You’re going to need to back that up.

There are obviously huge differences physiologically between people.

My neighbour’s got much nicer breasts than me for a start.

‘The primary function of carbohydrates is to supply energy for cellular work’ [Exercise Physiology, McKardle, Katch & Katch]. Basic.

I’m not sure you understand what you’ve quoted! Nobody is disputing what the primary function of carbohydrates is. This quote is saying that supplying energy is pretty much the only job of carbs (which is true), not that they are better for that purpose than anything else, e.g. fat (which IMO is disputable but highly dependant on a number of factors.)

I’ve also heard some stuff about delaying eating on longer endurance stuff (2h+) as a way to encourage the fat burning mechanism to kick in earlier. Reference please?

It doesn’t ‘kick in earlier’ it’s always there and active. Your body will just favour glycogen as it’s more efficient to use. So the ration of fat to glycogen burning is higher in glycogens favour.

If you start putting in more sugars your body will just continue using this. While still burning a minimal amount of fat.

By not eating for 2+ hours you are depleting your glycogen stores and forcing your body to burn a higher ratio of fat.

Molgrips do you also know anything about actively trying to manage blood PH as a way of also managing fat burning and fat deposits. That was something else that got my BS radar going (although I now see that there is something physiological in the clean dirty carbs thing).

Blood pH is tightly regulated, with something like a range of 0.1 pH units. The idea that this can be exogenously controlled to manage fat-burning activities sounds like woo-ism of the first order. So I’d say your BS-meter was accurately calibrated there.

Balancing acid and alkaline foods is an entrenched concept in all sorts of quackery, so no doubt there are reams of bollox to be found on this idea as it relates to diet and exercise.

I didn’t scroll back far enough.

Mol, muscle fibre types aren’t fixed. The longer you do something there more they will adapt. So if you are mostly type 2 but have been doing endurance sports for years, it’s likely your physiology would have changed

I know – I had a session with a physiologist at UWIC a few years ago, forget his name though. He told me that you have a genetic predisposition to one type or the other and that you can change. However, he said that you can’t really go from being mainly type I to mainly type II, but you CAN go the other way round. So he thought I’d be 40/60 I/II, but I could get to 50/50 with training.

Which tallies with received wisdom in other areas. My mum was a PE teacher (and previously a top sprinter) for many years, and she said what I’ve heard many other times since – you can make a distance athlete, but you have to be born a sprinter.

As for blood PH – never come across that.

If you start putting in more sugars your body will just continue using this. While still burning a minimal amount of fat.

Which is how it’s possible to do a 24 hour solo race and not lose any weight…

Ok, fats are good at supplying energy (they’re full of fat after all!) but try mobilising them at higher intensity. You simply won’t have the spare oxygen available to keep them company. I know carbohydrate vs fat isn’t binary, it’s a blend of differing proportions. My bad for abusing the shorthand. And full points to Ian for sneaky sub-text.

try mobilising them at higher intensity. You simply won’t have the spare oxygen available to keep them company

Yep, that’s why we do base training to improve oxygen delivery to our muscles, and therefore enable us to utilise a higher proportion of fat at a given power output, and/or provide more energy from fat to contribute towards maximum power output for threshold efforts.

This is chapter 1 page 1 of cycling training.

That is dead wrong. It IS a biological speciality.

There are obviously huge differences physiologically between people.

I think you are going to have to prove both these things.

Remember that I work in Intensive Care, where the fine manipulation of many, many physiological parameters is what I do.

If there are huge differences, you will be able to tell us what they are. If ‘sprinting’ is a biological speciality, you’ll be able to tell us what defines it.

I think you are confusing the ability displayed by the outliers in any population, the ability to run faster, the ability to lay down fat supplies for lean times and so on, and extrapolating this to imply that there are profound differences between humans.

Given that evolution works in a fairly well understood way, the variation in populations that you describe does not equate to ‘huge’ differences.

Ok, fats are good at supplying energy (they’re full of fat after all!) but try mobilising them at higher intensity. You simply won’t have the spare oxygen available to keep them company.

I don’t think anyone is saying otherwise (?)

I think you are confusing the ability displayed by the outliers in any population, the ability to run faster, the ability to lay down fat supplies for lean times and so on, and extrapolating this to imply that there are profound differences between humans

You just agreed with me. The differences I’m talking about are exactly that – the ability to run faster, or for longer etc.

I meant profound in the limited area of sporting performance and metabolic profile. Not like saying some of us have green blood or eat nails or something.

If there are huge differences, you will be able to tell us what they are. If ‘sprinting’ is a biological speciality, you’ll be able to tell us what defines it.

Why would I? I know lots of facts whose origins I can’t define.

and metabolic profile

Go on….

I can’t provide scientific levels of detail. But I challenge you to do the same for your point of view – not to win an argument, but because I would be genuinely interested to learn.

However, as we know, some people can eat whatever they want and not get fat, and some people don’t eat much and stay chubby. Why would this be the case if we were all basically the same?

Ok, fats are good at supplying energy (they’re full of fat after all!) but try mobilising them at higher intensity. You simply won’t have the spare oxygen available to keep them company.

I think this is very relevant when the context of serious athletes who are trying to maximise their performance. I think it’s less relevant when in the context of someone doing sport recreationally. FWIW I’ve spent time (7-10 days at a time) in ketosis (approx 50g/carbs per day) and been able to run, sprint, play squash and lift weights fine. I also regularly fast for up to 48 hrs and exercise intensely prior to breaking the fast with no problems. I never take on just carbs during long rides/runs. For me certainly carbs are not the be-all and end all. No real scientific evidence to provide, sorry, just personal experience!

This is chapter 1 page 1 of cycling training.

I thought everyone had thrown out chapter one, and declared that 30 seconds of HIT was just as good 🙂

However, as we know, some people can eat whatever they want and not get fat, and some people don’t eat much and stay chubby. Why would this be the case if we were all basically the same?

I’m equally not interested in winning any argument, and I know that this subject is one we can, will, do and will continue to disagree on, I also admit to not having the answer to the questions you are asking..

I think we are all basically the same from a physiological point of view. I think the differences you are describing are an expression of small physiological differences amplified by behaviour and environment.

The classic ‘western’ diet is high is easily obtainable, high carb, high fat foodstuffs. This has been the case for 30-40-50 years now, and the impact of this lifestyle on immigrant communities is the best example of the environmental and behavioural effect of this.

Talking to dieticians at work; they don’t make allowances for people who ‘like carbs’, they don’t make allowances for people who are overweight. When they prescribe feeding (via nasogastric tubes), they prescribe on the basis of ideal body weight; in other words, they view obesity or over or even under weightness as a problem which can be corrected by feeding.

I’m in a similar position to you; I can’t bring you the science on a plate, but we are pretty much the product of X million years of evolution, and I suspect that process would work to make us more similar rather than more different.

The classic ‘western’ diet is high is easily obtainable, high carb, high fat foodstuffs.

And yet, for a significant minority, it doesn’t cause weight gain. I think it’s more than just small differences.

Another example is young men who want to build big muscles in the gym. Some can’t do it no matter how hard they try, they just get wiry. Some bulk up easily.

I suspect that process would work to make us more similar rather than more different.

Oh I dunno. A range of different abilities could be quite useful even in prehistoric societies. An interesting topic though – some googling on muscle fibres revealed some studies that looked at lots of mammal species and found that differences were far greater in some species than others. This is true of lots of characteristics, and I believe humans are one of the more morphologically diverse species out there.

Don’t forget we’ve also got large scale regional differences, and these genetic traits are now being spread all about the population with modern travel.

Talking to dieticians at work; they don’t make allowances for people who ‘like carbs’

Your line of work though crikey is keeping people alive. If you spoke to people whose job it was to make cyclists as fast as possible, you might get some quite different viewpoints.

The question is, why exactly do I like carbs? What’s different for me? what draws me to sweets and fizzy drinks, compared to say my Mum who would go for crisps and savouries? My parents ate far more sweets as kids than I did, because there weren’t healthy food campaigns back then. Is it simply conditioning, or a result of some psychological issue rather than physiological?

Remember I’ve been fannying about with training for years. I’ve got a lot of experience with what happens if I just force myself to eat less and less. I can do it, but I lose the ability to train the way I want to. So my aim is to find out the best way of fuelling this particular body for the particular training and racing I want it to do, and to a lesser extent vice versa.

If I don’t train and just diet, I find it quite easy to do without the fast carbs, so that tends to imply it’s not just psychological.

I’ve spent time (7-10 days at a time) in ketosis (approx 50g/carbs per day) and been able to run, sprint, play squash and lift weights fine.

Reading people’s iDave diet experiences posted on here is interesting. Some people say they experienced no detrimental effect on their riding at all, and some report similar to me, in that they’ve found it necessary to eat extra carbs to support their max efforts.

Two people might be riding up the same hill at the same speed, but different things could be going on in their muscles.

I think we probably agree on the idea that there are differences, but my take on it is that they are far less physiological and far more behavioural and environmental in nature.

I think a look at the stats for obesity over time make interesting reading; again only my opinion, but the growth in obesity is happening too quickly and in too well defined a geographical area for it to be a change in physiology; it has to be behavioural and environmental.

I will say at this point that I’m not suggesting that weight gain = sloth and gluttony, I am intimately aware of the pressures and opportunities afforded us by the availability of food and the societal changes that lead to less exercise being taken. I think this is where the complexity lies rather than in physiology.

but my take on it is that they are far less physiological and far more behavioural and environmental in nature.

Hmm maybe.. but my point still stands that you could very easily pick two people with very similar lifestyles and diet, and find one obese and one skinny as a rake.

Take binners for example. He rides loads, far more than me, and is still rather chubby and quite slow! Chubbiness could be down to diet alone but slowness?

I think a look at the stats for obesity over time make interesting reading; again only my opinion, but the growth in obesity is happening too quickly and in too well defined a geographical area for it to be a change in physiology; it has to be behavioural and environmental.

Ah well now you’re talking about the obesity epidemic. You’re quite right on that subject I think. On a macroscopic scale, make the diet ‘worse’ (for want of a better word) and more people will become obese, for sure.

For normal everyday people, maybe those who do a bit of sport, I’m sure you’re right that the psychological landscape is the biggest factor in obesity.

My point though is about the individual. For any specific individual certain stimuli have certain effects, and those can be quite different to other people.

Gotta go shopping, back later!

Take binners for example. He rides loads, far more than me, and is still rather chubby and quite slow! Chubbiness could be down to diet alone but slowness?

Although I’m not sure we should be using Sir Chubby Slowcoach as an example, I think both these er, attributes of binners are eminently trainable, because I think they are based in behaviour and environment rather than physiology.

Maybe we are getting to a central element of the debate; if you think that physiology is the defining factor, does this mean that things like speed and body weight are fixed (for a given physiological range..) and therefore unchangeable (for a given physiological range)?

I would suggest that these things are able to be improved on to a greater point than if they were pre-programmed, like height, hair colour, etc.

Synopsis?

I’m hoping that Solo has pitched up and asked for lots of evidence.

I’m 12st 0 today, but that’s probably more down to a dose of the D&Vs as much as anything else.

Synopsis…

The usual STW diet thread, basically.

Although better mannered than some of late. 😀