Ketogenic diet vs standard high carb diet for runners

The ketogenic diet is an old treatment for seizures. But the high-carb diet is just poison. You turn nearly all of it to fat anyhow.

Some athletes think they use up a lot of carbs in training. Nope! A few hundred calories, that's all. Where the energy really goes is in recovery, building and repairing body tissue, and you don't need many carbs for that.

High fat diets aren't ketogenic unless you're eating almost no carbohydrate at all.

Arne Gabius (German Marathon Record) tried this for a limited time building up to his race.

Guess it broke him in the long term tough, it’s to harsh on the body.

Thank you for information. I did know that it has so much importance.

Bad Wigins wrote:

The ketogenic diet is an old treatment for seizures. But the high-carb diet is just poison. You turn nearly all of it to fat anyhow.

Some athletes think they use up a lot of carbs in training. Nope! A few hundred calories, that's all. Where the energy really goes is in recovery, building and repairing body tissue, and you don't need many carbs for that.

High fat diets aren't ketogenic unless you're eating almost no carbohydrate at all.

That's true. Like the old saying "everything in moderation" you certainly do not need to carbo load for a 5k, but you can't swing the pendulum completely the other way and expect good results.

You need enough glycogen to reload your muscles and stock your liver after a workout. You burn through a little of that between that time and the next day so you need a little more for the next workout.

To YMMV, It's true that we use more than one energy system. Nobody here is denying that. The energy systems are on a continuum so that your body is using more than one at once all the time. The percentages change during your duration and intensity.

But for aerobic respiration the quickest process is the use of pyruvic acid produced from glycolysis. When your body runs out of glycogen it will seek a high percentage of the next best thing in lipids. The physiological process or breaking down lipids for fuel is amazing but it takes a very LONG time. The result is you WILL be slower. Nobody can avoid this.

The only thing that you may have adapted to is your body's ability to store enough glycogen from the diet that you are now using. If you are running well than you are taking in glycogen.

If you say we are wrong that using lipids as a higher percentage source of energy is slower then you are either trying to mess with us or you do not understand basic physiology. The idea that your body can get "used to" breaking down fats as fuel and somehow become more efficient than the glycolytic system is just silly. It would be like saying the aerobic system with enough training can be as quick than the phosphocreatine energy system. This is basic stuff.

The Art and Science of Low Carbohydrate Performance by Phinny and Volek is a very good book for runners who want a more scientific understanding of the high fat/low carb approach. Here are some key points.

1. Over many years, our bodies have adapted to burning mostly carbs and storing fats.

2. This can be changed, but it takes 2-3 weeks of severe carbohydrate restriction to train the cells to burn fat as a primary fuel. During this period, performance will suffer and you will feel bad. The reason is technical, but basically, you are starving your brain.

3. The high fat/low carb diet is a no-brainer for the obese looking to lose weight and ultra athletes, but not so much for everyone else.

4. Athletes who don't do ultra events will need to modify their diets to include more carbs/protein after training and before competitions. How much modification? You have to test for yourself to find out.

5. If you cheat on the diet for more than a few days, the cells revert to burning carbs and you have to go through the 2-3 week adaption phase again.

There is also a very wide response to burning fat as primary fuel. Some runners can burn 30g/hour of fats. Others can burn 60g/hour. Runners who fall into the higher range are well suited to training and racing on a high fat/low carb diet.

TL;DR

What works for me was a 2-week extreme reduction of carbs and increased intake of healthy fats. Now, I fast about 16-18hrs about 5 days a week, consuming only healthy fats from 7PM to 2PM. Since I work out in the morning, my body only has fat calories to burn. From 2-7PM, I eat normally... no junk food, of course. Intermittent fasting keeps my cells in a fat burning mode.

This diet has greatly reduced my problems with extreme hypoglycemia, an inherited condition in my family, and it has reduced my cravings for food.

I do not consider it to be a performance diet. For me, it manages hypoglycemia.

I don’t know what to tell you guys so you understand.

That is great you have adapted to burning lipids as a primary source. BUT, it is still a slower process. You can not change that fact.

I am reading that a low carb diet can lower Testosterone. That's reason enough to avoid for me.

YMMV wrote:

If you understood physiology, you would know why they do this, albeit they use carbs at a much lower rate than their not-as-fat-adapted competition (see the excellent FASTER study by Volek and Phinney).

That study is p!$$ poor

1) too small a sample size

2) All Ultra runners while having the length of the study at 3 hrs at sub maximal race pace (in around 64% Vo2max)

Its a bit like deriving data for a Marathon based on Usain Bolt running a 400

When you actually look at it the study is saying you burn fat in the fat burning zone, Revolutionary!

HarleyQuinned wrote:

YMMV wrote:

If you understood physiology, you would know why they do this, albeit they use carbs at a much lower rate than their not-as-fat-adapted competition (see the excellent FASTER study by Volek and Phinney).

That study is p!$$ poor

1) too small a sample size

2) All Ultra runners while having the length of the study at 3 hrs at sub maximal race pace (in around 64% Vo2max)

Its a bit like deriving data for a Marathon based on Usain Bolt running a 400

When you actually look at it the study is saying you burn fat in the fat burning zone, Revolutionary!

The FASTER study was good, but it only showed that people's systems adapt to what they eat. Duh. So you burn more fat when you eat more fat. Congratulations? It may have applications for ultrarunners like YMMV said where you can eat fewer carbs and have less GI probs, but it has no other performance advantages. Camille Herron said it was using Muerten that allowed her to get more energy with fewer probs, so there are other ways to skin a cat.

And by the way, Timothy Olson was in the FASTER study and he says emphatically that keto does not work for him and carbs are very important. He eats more primal and higher fat than most runners, but the FASTER study is not necessarily an endorsement of going all the way keto.

YMMV wrote:

I've been on keto/fat adaptted for three years...

I was a vegetarian quietly "saving the planet while eating healthy" for two decades...

If you don't have the discipline and awareness for intermittent fasting, you will never succeed on any diet...

Congratulations, you've hit the trifecta of extreme dietary approaches!

Have you noticed that a high percentage of those who love maximalist shoes (e.g. Hokas) are those who used to love minimalist shoes (e.g. Vibrams)? It's the same with diet: some people have a personality that drives them to constantly search for "the secret." I look forward to hearing what incredible new diet will have finally solved all your problems in another decade.

The funny thing is that people who've made complete 180-degree turns in their dietary approach are always the most firmly convinced that their new approach is the right one.

Excellent post.

YMMV wrote:

I find veggies very tasty and useful, and since carbs are NET carbs, then there is little need to restrict green veggies. I eat far more greens than the average runner, and more even than most vegans. Net carbs are very low, until you get into starchy veggies. Nuts are fine, although you have to consider omega-6 content. Avocados are great in every way, and a some nice tangy goat cheese with the salad is a treat.

The main foods to avoid are all grains, processed vegetable oils, and an excess of fruits. These are either too low in nutrients per calorie, or contain toxic antinutrients which create health problems.

Excuse me, but what are toxic antinutrients??

fisky wrote:

Some runners can burn 30g/hour of fats. Others can burn 60g/hour.

So what? That's 540 kcals per hour.

If an elite runner burns 120 kcals per mile for one hour racing 13 miles thats 1540 kcals.

There is a parallel of using keto/metabolic flexibility in diet, and employing barefoot/minimalist footwear in training and racing. If an athlete runs 40% of their mileage barefoot, do we say that barefoot doesn't work because of the miles they run in shoes? If an athlete is in ketosis 40% of the time, are they a "keto runner", or re they "blowing it" by taking in carbs selectively?

Note that almost no professional runners currently seem to train barefoot/minimalist, yet there are posts on LRC daily about the benefits many have had using it to overcome injuries and train longer and get faster. In years to come, I suspect that there will be more athletes like myself who use metabolic flexibilty in their diet to control inflammation, enhance recovery and improve health markers, without diminishing the ability to generate wattage during more intense workouts. I know I have been able to do so, and while I am persistent and adaptable in certain ways, I am not particularly gifted, and it will be up to anew generation of athletes looking at these issues more objectively to decide how and when to implement the tools properly.

The sure way to stall progress is to look at the issues from a predetermined, agenda-driven standpoint, which unfortunately drives much if not most of the discussion of diet, health and exercise.

Billy blue 47 wrote:

Anyone know any high level

Runners. Not your local cross fitters ... but anyone competing at a high level on the keto diet?

Not even crossfitters push this diet. Their workouts are intense to keep you anaerobic

YMMV wrote:

Young, heavy-training genetic outliers are not inclined to take away one of their greatest pleasures in life: shoving carbs down the gullet. It is not until they retire and have to think about their health and expanding waistlines that something like keto would even get on their radar.

A couple of ultra guys (Jeff Browning and Zack Bitter) have had great success with it, as well as some of the top TDF guys. I am keto and it hasn't hurt my shorter distance stuff, but hasn't boosted it either (though I am healthier and more durable). It does make weight control effortless, so I am at my best weight ever for running/climbing in my 60s.

What 20-something athlete is going to voluntarily give up beer (or ugali, if Kenyan)?

Are you sure Jeff Browning is keto? I know he's low carb but have never heard/seen any reference that he is full on keto. Also, I think its hard to argue his low carb diet is actually doing anything for him performance wise. Sure, it might have some effect. But I imagine 20 years of running ultra's and his slow ramp up in competitiveness likely has much more effect ie consistent training over a long period of time.

Jeff is keto part/most of the time, but more specifically is OFM (optimal fat metabolism) which is being metabolically flexible so that on a base of fat-burning you target carbs for workouts and/or races. He attributes a huge part of his recent success to his change of diet. He is eloquent in his story which very much mirrors mine, but at a higher level of performance (unless maybe you account for age difference).

Keto? Naaaah. No fruit, really? I'd better maintain an adequate diet, as I do, actually. I mean you shouldn't limit yourself anyway withing reason. I found an interesting essay on https://essayexplorer.com/review/essaytornado about why almost all the diets are harmful. Ater reading all this, I stopped torturing myself in this way. My life has changed fundamentally since than. I this this information is useful and worth reading for everyone.