Keto Diet - who would benefit from it?

[hellymedic]

I don't know how lack of a bile bag might change this.
Have you noted any difference?

[mattc]

<much good stuff snipped>
...
Does it have a downside?  Yes, you lose some efficiency/ability for sudden delivery of very high power through a switch from glycogen as the primary muscle power source.  You will never see an Olympic athlete on this diet as they need to have sudden power delivery for a final sprint and they can always refuel adequately.

I don't really agree with this. There are plenty of events where no sudden spurt is required. (a simple example - you hardly ever see a sprint finish in the marathon, and when you do they are hardly putting out 800W.)

Also, plenty of athletes use the "train low, race high" approach. [I'm sure google will find you some citations.] So their training diet isn't damaging their race-day performance.

You sure about that?

Might want to check their running speeds.

The best marathoners do about 13mph, right? That's hardly a sprint.
Whereas even Kipchoge could go a LOT faster than that over a stand-alone 100metre race. (yes I know he'd get nowhere near, say, 10s for the distance, but he'd manage a lot faster than 17seconds!)

Is that what you meant? 

[Kim]

I don't know how lack of a bile bag might change this.
Have you noted any difference?

Only in the lower digestive tract.  Too long (12 hours or more) without eating some fat and I'll be on a slow journey up the Bristol scale.  My tolerance for certain foods is much reduced - really fatty stuff like chips^[1] rarely ends well, and while my tolerance for tomato has increased over the years since the surgery, I have to be careful about onions.  I can tolerate more of these when diluted with sufficient easily-digested carbs (white rice, bread, pasta, etc.).  I was never a big fan of particularly fibrous foods, but these days I actively avoid consuming too much of it, to avoid poosplosion.


_{[1] I now refuse to eat chips unless they're *really* nice and I don't need to go anywhere in the morning.  It's simply not worth the consequences.}

[Cudzoziemiec]

If that's not the case, then we may as well all give up and become eating machines.

Well that's the point of all life forms, isn't it? Eating and reproducing machines.

As Helly points out:

Storable carbs brought us literacy, commerce and culture.
Hunter-gatherer societies are seldom able to record wisdom and pass on any knowledge between multiple generations.
The 'diseases of civilisation' attack those whose lives are not 'nasty, short and brutish'.

But that's just complicated human stuff.

[mrcharly-YHT]

<much good stuff snipped>
...
Does it have a downside?  Yes, you lose some efficiency/ability for sudden delivery of very high power through a switch from glycogen as the primary muscle power source.  You will never see an Olympic athlete on this diet as they need to have sudden power delivery for a final sprint and they can always refuel adequately.

I don't really agree with this. There are plenty of events where no sudden spurt is required. (a simple example - you hardly ever see a sprint finish in the marathon, and when you do they are hardly putting out 800W.)

Also, plenty of athletes use the "train low, race high" approach. [I'm sure google will find you some citations.] So their training diet isn't damaging their race-day performance.

You sure about that?

Might want to check their running speeds.

The best marathoners do about 13mph, right? That's hardly a sprint.
Whereas even Kipchoge could go a LOT faster than that over a stand-alone 100metre race. (yes I know he'd get nowhere near, say, 10s for the distance, but he'd manage a lot faster than 17seconds!)

Is that what you meant? 

Try running a single 5 minute mile and then come back and tell me that isn't putting out a lot of power.

[zigzag]

yes, marathon is a high intensity activity (provided it's done properly - not jogging or walking, but running all of it) and it will burn through glycogen reserves during the first ~25-30km.

[hellymedic]

I am very much NOT a runner but my understanding is that marathon runners plan/pace their efforts to reach 'the wall' (bonk/total glycogen depletion) on the finish line.

[musing] I don't think this is particularly healthy and might explain, in part, why a tiny proportion drop dead at that point.

[mrcharly-YHT]

I am very much NOT a runner but my understanding is that marathon runners plan/pace their efforts to reach 'the wall' (bonk/total glycogen depletion) on the finish line.

[musing] I don't think this is particularly healthy and might explain, in part, why a tiny proportion drop dead at that point.

Doesn't work like that. If you are a slower runner, you will hit the wall well before you finish. You need to take on fuel - modern sports drinks and gels make this relatively easy.
The elite runners can manage to complete a marathon before hitting the wall.

If you are 'just jogging' then it is possible to switch to other pathways and keep going; most of us can walk for 5 hours without eating. We won't collapse. I've paddled a kayak at a reasonable pace for 2.5hours without hitting the wall (about 25km) - I don't have the muscle fitness to push myself hard enough, my body had the reserves to keep up with the burndown rate.

[mattc]

<much good stuff snipped>
...
Does it have a downside?  Yes, you lose some efficiency/ability for sudden delivery of very high power through a switch from glycogen as the primary muscle power source.  You will never see an Olympic athlete on this diet as they need to have sudden power delivery for a final sprint and they can always refuel adequately.

I don't really agree with this. There are plenty of events where no sudden spurt is required. (a simple example - you hardly ever see a sprint finish in the marathon, and when you do they are hardly putting out 800W.)

Also, plenty of athletes use the "train low, race high" approach. [I'm sure google will find you some citations.] So their training diet isn't damaging their race-day performance.

You sure about that?

Might want to check their running speeds.

The best marathoners do about 13mph, right? That's hardly a sprint.
Whereas even Kipchoge could go a LOT faster than that over a stand-alone 100metre race. (yes I know he'd get nowhere near, say, 10s for the distance, but he'd manage a lot faster than 17seconds!)

Is that what you meant? 

Try running a single 5 minute mile and then come back and tell me that isn't putting out a lot of power.

How much is "a lot"?
(The amount of power that *I* can generate isn't very relevant.)

[mattc]

yes, marathon is a high intensity activity (provided it's done properly - not jogging or walking, but running all of it) and it will burn through glycogen reserves during the first ~25-30km.

Again, "high intensity" is all relative. I'm aware of the difference between jogging and racing for 40km. Are you aware of the difference between a marathon and a sprint?

Your 30km figure could well be right - but as you will see in my post, I did refer to train low, race high.

Of course you are kinda proving my initial point; there is only 1 Olympic running event longer than 30km!

[zigzag]

sprint and marathon are both high intensity disciplines, different level of high, but still high. same as in cycling, take a hill climb competition and a classic one day race - they are high intensity in their own way. just riding along (akin to walking) is low intensity - i could ride all day long without bonking and needing any food.

[Jakob]

No, a sprinter will use, what, 12-1300watts, whereas a regular (pro) rider will for the most time ride at ~250watts. A body in ketosis may be able to convert fat to energy fast enough for 250watts, but is utter incapable of doing that for 1300watts, so you need sugar.

I know from my own kendo training, that I will start fading after 5 minutes, so at recent tournament, I supplemented with gummybears between each match, in order to make sure that I had enough energy. 

[zigzag]

No, a sprinter will use, what, 12-1300watts, whereas a regular (pro) rider will for the most time ride at ~250watts. A body in ketosis may be able to convert fat to energy fast enough for 250watts, but is utter incapable of doing that for 1300watts, so you need sugar.

i assume it's a typo (twice?) for 350w? even a mamil like me can ride at 250w for few hours, and not in a race..

https://www.cyclingweekly.com/news/racing/five-hours-363-watts-wout-van-aerts-strava-ride-reveals-his-massive-effort-at-strade-bianche-371860

[Jakob]

Yeah, my memory must have been broken...350watts is a more typical 'average' pro output.

[mrcharly-YHT]

If an elite marathon runner is running a race on the ketosis pathway, they are going too slow.

Someone else will go faster.

There, mattc, now do you get the point?

For such a (relatively) short duration race (just over 2 hours), the keto energy pathway isn't the right one.

[mattc]

MrC, you might want to check the last line in my post that triggered you off:
[in bold]

<losing top-end power...>

I don't really agree with this. There are plenty of events where no sudden spurt is required. (a simple example - you hardly ever see a sprint finish in the marathon, and when you do they are hardly putting out 800W.)

Also, plenty of athletes use the "train low, race high" approach. [I'm sure google will find you some citations.] So their training diet isn't damaging their race-day performance.

You sure about that?

Might want to check their running speeds.

What I also was thinking about this is that MANY olympic events are not power (or endurance) sports; they are skill-based. (although nearly all require a high-level of strength conditioning, or whatever the current jargon is) The track athletics only accounts for a tiny %age of the final medals table.

[mattc]

No, a sprinter will use, what, 12-1300watts, whereas a regular (pro) rider will for the most time ride at ~250watts. A body in ketosis may be able to convert fat to energy fast enough for 250watts, but is utter incapable of doing that for 1300watts, so you need sugar.

i assume it's a typo (twice?) for 350w? even a mamil like me can ride at 250w for few hours, and not in a race..

https://www.cyclingweekly.com/news/racing/five-hours-363-watts-wout-van-aerts-strava-ride-reveals-his-massive-effort-at-strade-bianche-371860

This is the kind of difference I am talking about: 350W vs 1200W is a huge gap.

For a more human illustration, read Wiggo's account of his Hour record, and how absurdly easy he was finding it for the first 12minutes.

[hellymedic]

If an elite marathon runner is running a race on the ketosis pathway, they are going too slow.

Someone else will go faster.

There, mattc, now do you get the point?

For such a (relatively) short duration race (just over 2 hours), the keto energy pathway isn't the right one.

I'm not sure that's quite right. I think if you want maximal power, you need to 'fire on all cylinders' and 'burn' sugar, glycogen, belly fat and subcutaneous fat simultaneously. An elite runner may be ketotic at the finish line but they are not just running on ketones.

[Chris S]

No, a sprinter will use, what, 12-1300watts, whereas a regular (pro) rider will for the most time ride at ~250watts. A body in ketosis may be able to convert fat to energy fast enough for 250watts, but is utter incapable of doing that for 1300watts, so you need sugar.

i assume it's a typo (twice?) for 350w? even a mamil like me can ride at 250w for few hours, and not in a race..

https://www.cyclingweekly.com/news/racing/five-hours-363-watts-wout-van-aerts-strava-ride-reveals-his-massive-effort-at-strade-bianche-371860

This is the kind of difference I am talking about: 350W vs 1200W is a huge gap.

It is a huge gap, but aren't the figures meaningless without specifying duration? Hell, even I - a fat bloke pushing 60 with COPD - can push out 350W; just not for long. Young bloods who can do 1500W+ do so for just a few seconds.

[sojournermike]

If an elite marathon runner is running a race on the ketosis pathway, they are going too slow.

Someone else will go faster.

There, mattc, now do you get the point?

For such a (relatively) short duration race (just over 2 hours), the keto energy pathway isn't the right one.

I'm not sure that's quite right. I think if you want maximal power, you need to 'fire on all cylinders' and 'burn' sugar, glycogen, belly fat and subcutaneous fat simultaneously. An elite runner may be ketotic at the finish line but they are not just running on ketones.

Helly hits the nail on the head. The proportion of fat/carb useage is individually determined by adaptation, training and genetics, but faster increases carb useage Some athletes burn more fat for more output than others, which is probably an advantage in ultra endurance sport and (even) marathon, if only because it spares carb for later in a competitive race. I understand that there is also some evidence that a sustained keto adaptation may impair the 'top end' of carb fueled performance, which is pretty important if your an 800m runner say.

At the end of most races I ever ran, I think I was primarily fueled by Ceatine Phosphate. Perhaps I wasn't fast enough to get away from the pack...

[hellymedic]

I know I've posted this before..

I was never fast but learned to optimise my performance.

I used to time my 'fast commutes' - parents in Golders Green to Hillingdon Hospital via A 502, A406, A40 and Long Lane, usually before 6am on summer mornings.

My Friday commutes were always the fastest. They were mostly fuelled by my Tea with Grandma on Thursday. Parkway Patisserie Honey Cake, with its mixture of flour, sugar, oil, honey and egg seemed to provide an optimal mix.

I went like the wind; 52 minutes of almost flat-out - HR 145-175 riding.

Didn't seem to get 'Friday legs', though I was commuting more slowly almost every day. I'm sure I was firing all cylinders - just never had a good engine...

[rafletcher]

This seemed quite interesting.

https://trainright.com/should-endurance-athletes-go-keto-ketosis-ketogenic-diets-for-endurance-athletes/

[ian]

Pretty much what I was saying, and not just applicable to endurance, but generally. I think it's generally a case that you lose weight on a keto diet through calorie restriction rather than something magical about the diet.

[mrcharly-YHT]

If an elite marathon runner is running a race on the ketosis pathway, they are going too slow.

Someone else will go faster.

There, mattc, now do you get the point?

For such a (relatively) short duration race (just over 2 hours), the keto energy pathway isn't the right one.

I'm not sure that's quite right. I think if you want maximal power, you need to 'fire on all cylinders' and 'burn' sugar, glycogen, belly fat and subcutaneous fat simultaneously. An elite runner may be ketotic at the finish line but they are not just running on ketones.

I think we are agreeing.

The point I'm trying to make is that you can't compete in an elite-level marathon on just a keto diet basis.

I agree that there are some olympic sports that are almost purely skill-based (rifle and pistol shooting come to mind). Even those require some physical conditioning, but it is not the level of physical power, endurance or speed that determines a win, it is primarily skill.
Dinghy sailing is an interesting sport, as it is primarily skill (with an element of chess-like calculation) and a very high dependency on physical conditioning.

[TPMB12]

So where's a good source of information on the keto diet? For information on what you can eat but recipes too.