Eating, Carbs and Keto

I did keto once, for about 10 days until I just became utterly bored with the diet. I ate eggs, sausages (chosen for low carb content) cheese, almonds, tuna, mackeral and white fish, chicken and bacon. I cooked everything I could in as much oil as i could just to make up my calorie requirement. My main criteria was to get the carb intake below 20g per day. I also tested my pee each day with dipsticks to see how much ketones I was producing. I felt lethargic to begin with but picked up and was at full throttle by the end. I also took carnitine daily, it's supposed to help burn fat.

My main benefit seems to have been a much improved ability to go without any food for 24/36 hours, as in the 5/2 diet. I can easily stop eating and not feel hungry after the first 6 hours. I can also do HIIT in the morning on an empty stomach without feeling sick. Thats supposed to boost repair hormones etc.

Can't say that my overal performance improved, but perhaps I did reverse the slide in performance I seemed to suffer when I followed the advice in a book from a certain doctor who coached US teams a few decades ago, and was firmly of the opinion that to do well at longer duration races, you had to use carbs as fats just didn't cut the mustard.

I'm firmly of the opinion that everyone is different, what diet works for one won't be beneficial for another. Keep trying things until something works for you. For instance caffeine works for some as an enhancer, but for me, just makes me tired.

edited to add. When I was doing the high carb thing, I found myself bonking much more frequently and much harder. It was when I still had 10 miles to get home and was reduced to little more than walking pace, that I decided that I needed to look again at the supposed benefits of the high carb, low fat diet. Conversely, I have never bonked when on a diet more 50/50. And I can still sprint like a 25 year old when I want to. (OK, 26 year old)

I've just registered as I came across this thread and had a read through and haven't seen many comments from people actually on the diet.

I have been following a keto diet for around 8-10 weeks now and lost around 11kg.  I fit into clothes I haven't worn in about 2 years and feel much happier.  During this time I have been very busy with work and my cycling has dropped off to about once a week so can't comment to much on the way it affects my cycling however the rides I have done since being on keto I haven't had the sugar crash I'd normally feel.  Under normal conditions I would have to take on food atleast once an hour or I would slow right down, feel light headed and become extremely irratable.  I can now manage 3 hours on the bike and feel fine!.  

I completed the Cotswold Half Iron distance in August in about 6 3/4 hours at a weight of 107kg and after 8 months of dedicated training but almost no weight loss, I tried cutting my food intake in the normal way but then my training suffered, I felt like I was in a catch 22.  I said I would never try another one however I am now seriously tempted to sign up again to see how keto affects my training and race day results as I think the change will be significant.

The greatest difference for me being on keto is nothing to do with sport but is that I don't get hungry during the day, or if I do I know it's because I NEED to eat, not any other reason.  I find that if I miss lunch because I'm busy or I forget then I'm OK, pre-keto I couldn't make it to 11AM without starting to think about lunch!!  I've found this a genuinely life changing and liberating experience, I feel like I've had some sort of handcuff removed and am finally free!  Pretty much soley due to this I plan to stay keto now as the benefits far outweigh the negatives.

The hardest part was starting, for help I would suggest looking at r/keto on the reddit forum, they have an FAQ in the side bar which is extremely comprehensive.

The most important part with any diet is that what has worked for me may or may not work for you, and arguing about it on the internet isn't helping you to achieve your goals.  My goal was to lose some weight on this diet and instead I've found a lifestyle change that I can sustain (and achieved some milestone goals).  If it works for you then great but if it doesn't, don't let that stop anybody else having a go because they might just end up as happy as I am!

@ beezus fufoon

Tim Noakes, Volek, Bergstrom all have multiple papers on the topic. There are literally hundreds on the metabolic changes, performance effects etc on the likes of pubmed / google scholar.

Bergstrom was publishing on this in the late 60's. It really isn't anything new, and certainly cyclists have been utilising the effects for many years. Most top cycling (and marathon coaches) will get their athletes to do a long training (2 hrs running, 4 hrs cycling) followed by an hour or so interval session or tempo riding to deplete glycogen reserves and enhance fat metabolism. The chronic calorie restricition practised by elite endurance athletes to keep weight down, by default keeps them in a fat burning state and enhances their fat burning ability well above that of the normal populace

(NB. A theory is a scientific idea tha has been tested exhaustively and has been widely accepted as representing a good model for the observed phenomenon. A theory is something that has already been backed up by the science)

@beezus fufoon, it all depends on the intensity of the work out, the person etc etc. 60 - 90  minutes is a pretty broad spread. Liver glycogen is a relatively small store , about 25 % of the total store. At half marathon race pace (60 - 65 min) elite athletes approach the end of their glycogen stores. At marathon race pace (125 min) elite athletes approach the end of their glycogen stores... horses for courses.

@ianrobo If your resting HR is 45, max 190 your 70% HR is 145 - 150. As I said,  steady state efforts at this level can be undertaken for many hours in well adapted individuals, but if you have periods of intensity above this(as typically happens in say a race or gran fondo, hilly ride etc) then you will begin to deplete your glycogen stores. Gluconeogenesis is, except in ketogenic individuals at rest, a very minor contributor to glycogen stores, and metabolically expensive so will make a very minor contribution to energy expenditure during exercise.

You do carry carbs in your body, but in racaing they will quickly become depleted. I rode a century recently with in Cat 1, 4:07 In the first hour I averaged 82% max HR. This was followed after 3 hours by 2 large hills at 90% HR If I hadn't taken about 800 cal of carbs with me I would have bonked for sure. 

I agree with your main point, that long rides can be readily undertaken without need for carb or even any fuelling. I rarely eat breakfast, lunch is likely to be a couple boiled eggs and a can of tuna, and I'll then do 40 - 50 miles training after working as a builder during the day before having dinner. I am something of a fan of keto-adaptation. It isn't for everyone though, YMMV.

How much glycogen does someone on a typical keto diet usually have stored in regular tissue and in their liver?

@madcarew

I think you have left the glycogen stored in the liver out of your formulation there - IIRC, 60-90 minutes is glycogen stored in the muscles, then you bonk, which then activates the liver to dump its stored glycogen

the theory of fat adaptation seems very similar to the same physical conditioning as upping the lactate threshold - by repeated training, the body "learns" to access those energy systems more easily and efficiently

when fat adapted, the lower regular insulin levels that the body has adapted to means that the release of the glycogen stored in the liver is far more gradual.

Not wanting to put myself up as an expert, but I do have a depth of experience both academic and practical on this.  

Here's to removing some obfuscation:

• There are 4 fuel sources in the body.

1. The first, aeroobic, fat, is constantly used by the body to fuel its processes. It is typically a slow burning system, not suited to high output efforts (good as the primary fuel source for an all day ramble, but not for a 1 hr TT). There are limitations on the speed fat can be metabolised due to the steps required. an 80 kg person who is 20% body fat has enough fuel on board to cycle at 10 mph for about 3 weeks without refuelling. Produces CO2 as a by product
2. The second, aerobic, glycogen, uses sugar / glycogen for efforts above  a basic level.  The body can only store enough for about 60 - 90 mins strenuous exercise. However, if this is done in bursts, people may go several hours before running out of glycogen stores. This is typically when the bonk occurs and they feel lacking in energy. Those who are well adapted for fat burning will find this less of an issue, as a higher percentage of their energy supply comes from burning fat, and so they are using less glycogen supplies. Produces CO2 as a by product
3. The third, anaerobic, glycogen, in a different energy system is for high energy  / maximal efforts that last up to  30 - 60 seconds. Produces Lactic acid.
4. The last, anaerobic, uses Creatine phosphate for efforts lasting up to a few seconds, typically from rest. The first 40 metres fo a 100 m sprint.

• None of these systems shuts down. We all burn fat as we sleep, and in the background as we go about our daily activities, to greater and lesser extents.  While we may be primarily using glucose for some activities we will also be using fat as well.
• There is a limit, for everyone, as to how fast they can metabolise fat into available energy. Typically it will be up to about 70% max HR. Beyond this you need to use glucose, so fat is good as a steady state fuel, but high energy efforts will enevitably deplete glycogen stores.
• Except for being in ketosis, the amount of fat you use is largely unrelated to your diet, and more to the regularity of your meals, and the intensity of your activity, and your physiology,  which can be altered with pracise.

Take a look at this: http://julianabuhring.com/keto-baby/

It is an interesting read.

That is ace.

I know who would disagree with all this. 

Not sure about going full keto, but I know a number of well regarded coaches are moving in that general direction;

http://optimumnutrition4sport.co.uk/2016/11/15/my-ten-nutrition-commandm...

https://www.youtube.com/watch?v=1UcIvv5KdJo

edit; thanks Ianrobo - fat adapted is the term I was looking for

Surely the loss of 10kg however you achieved it means you are using less energy than before? That may have a part to play in it. I am a type one diabetic and even the mention of keytones sends shivers down my spine

Is it possible/practical to do this and not lose weight? Specifically, being a vegetarian and already 12% BF is this going to require me to drink a litre of olive oil a day or something to keep up the calories?

Interesting. I've just finished reading Mark Beaumont's book about his race around the world. You can see how being better able to burn fat could be helpful in this sort of situation. On the other hand, he makes it clear in the book that finding enough of any sort of food was difficult at times and in some places around the world. Needing a particular sort of food could really slow an athlete down I think.

My limited understanding is that low carb training can work from some athletes, in that it trains the body to utilise fat as an energy source for long, low intensity, steady state efforts, and slightly increases the available power outpout from the drip drip metabolisation of fat stored in the body.

I'd like to see any work done on the "train low compete high" carbohydrate cycle, and if it makes the muscles more "spongey" as a glycogen store for power efforts in a long event.

But it's a very specific target market - I doubt that track cyclists and sprinters would go within a flying mile of it, and most recreational riders who are happy with 60-70 miles on Sunday morning and the odd ton on special occasions might not get much benefit from it.

My only other worry about going keto would be its flexibility and ability to react in a race context - making, or catching a break, domestiques ferrying water bottles from the race car, shepherding a sprinter into position. If an athlete's committed to improving LISS performance / efficiency, does it limit their ability to say "sod it, I'm/we're going balls out for 15 minutes"?

Fundamentally, although I can see the benefits in some circumstances - I could see it working well for RAAM and Transcontinental riders - it doesn't sound like it's much fun.