rubiksoval

Thank you. This 100% proves my point. 2MJ in 6 hours means you were riding at a very low intensity.

To compare, my ride today was 1,600 KJ in an hour 45 minutes. Meaning I was putting out about 3x the energy you were.

Fast/hard versus slow/easy. There's a massive difference in energy. Simply can't do that on fat.

rubiksoval

I'm curious how much faster you could go with adequate nutrition...

In all honesty, I'd probably ride similar speeds if I were trying to ride without carbs.

Endurance performance requires appropriate fuel.

burritos

Not me, but Kohei Uchimura, the goat of gymnastics was able to be the best without loading for performance and competition:


I understand that this is only one anecdotal example. But the hindrance of not carb loading did not stop him from being at the top gymnast.
For me personally, I'm not trying to achieve speed/performance, I'm trying drive fat metabolism. Same reason why I fast. Same reason why I exercise. That's not the same as losing weight. When you drive fat metabolism, AMPK(adenosine monophosphate kinase) is upregulated which is a major metabolic switch for autophagy, specifically mitophagy. This is the recycling of mitochondria. Healthy mitochondria=healthy cells=healthy person. Exercise also drives this pathway. What halts this path way? Insulin. What spikes insulin like an emergency brake on a subway? Glucose.

hubcyclist

I love it when non scientists talk about things like they actually know what they’re talking about, like talking about theoretical things like autophagy like it’s been actually observed in people (it hasn’t)

burritos

https://journals.plos.org/plosone/ar...e.0126546.g001


But you're right, I'm a wannabe and the stuff I'm spouting is just my opinion. Not scientific dogma. I apologize if I'm sounding like an arsehole.

hubcyclist

I stand corrected. Regardless there’s still a lot of conjecture and not a lot proven about a lot of dietary things like keto and even fasting. But even leaving those aside, I personally can’t see why most cyclists would want to intentionally limit their growth by limit carbs. You may be happy tooling around at a low speed, but a lot of cyclists ultimately want to get faster. by being keto one is effectively capping how hard they can ride and eventually that limits any future improvement, because once one gets closer to threshold and above, the body needs glycogen to be able to fuel.

burritos

That's perfectly fine. Please ignore me and I apologize for discussing the topic. It's probably all crap.

wolfchild

Eating carbs does not prevent fat burning...You can eat carbs and still burn fat.

burritos

https://pubmed.ncbi.nlm.nih.gov/21864752/

You are correct, but the question is if your body is predominantly burning fat vs predominantly burning carbs. Everyone knows that if you eat carbohydrates, your pancreas concomitantly releases insulin for your body to absorb that carb load. Since you're physically fit, you likely are metabolically flexible and can quickly switch from predominantly burning carbs to predominantly burning fat. The presence of insulin slows fat metabolism and promotes carbohydrate metabolism. And once you've released insulin, depending how carb/fat adapted one is, it may take 1 to several hours for the insulin to drop back down to baseline. From the above summary of insulin effects after eating glucose, why would the body want to both burn fat while it's actively trying to synthesize it? And why would it want to make glycogen at the same time that your body wants to break it down? Yes, the physical activity you're doing will eventually overcome these opposing metabolisms and eventually will lead to both carb and fat burning. But the insulin effect by eating carbs is still a transient physiologic obstacle to ultimately burning primarily both fat and ketones.

But if performance is crucial to you, especially if you're used to carbs, then carbs is a must. Carbs gives you instant energy. When you "bonk", for a carb burner, that's when you've run out of carbs. When people get their "second wind" it's because their carb metabolism has switched to a fat/ketone metabolism.

rubiksoval

It's not an anecdotal example. It has nothing to do with anything.

It doesn't really matter why you do what you do. The point is that people touting keto nonsense within the context of cycling performance don't know what they're talking about. Why you attempt to use a very slow 6 hour ride or a gymnast within that context is unknown. I'm not really interested in either of those two things.

Hondo Gravel

I need carbs. Not saying eat a dozen doughnuts but good quality carbs (beer). If it works for you that is great I tried keto and it didn’t work for me.

canklecat

Miller219

I've done both. Found Keto is great if you're planning a long less intense ride. But for fast attacks - recovery - then attack again, keto just won't do the trick over the course of a 1-2hr race ( I suspect the same is true for any race that features surging). I found I had no energy left after attacking only a few times. That being said - Keto is an easier diet to maintain once you've switched your eating pattern to match what is required to remain in ketosis - that is to say you don't have to worry so much about fueling for the ride as you probably constantly have an excess amount of body fat to fuel the ride. Carb diet does give that missing power/recovery ability that is missing from the keto diet. I've switched back and definitely see better results.

What would be an interesting experiment is practising a keto diet and only consuming enough fast-digesting carbs to fuel for the ride itself. Maybe it would result in burning fat for lower intensity and tapping into glycogen when the body needs it for higher intensity - whether or not that is possible is beyond my understanding.

mr_pedro

I have cycled a lot of miles while fasted and it feels great. I only do it for my slow rides though. For any effort longer than an hour or so at anything close to your limits, you start to need carbs. That includes carbs during the ride. Normally I don't drink any sweet drinks, but during hard rides I go for 100 g of sugar per hour mixed in with the water.

Carbonfiberboy 

Really? 400 calories an hour and one bottle of water? You're better than a TdF pro! All a result of riding fasted, eh?

mr_pedro

That comment is so far off, you either misinterpreted my comment or you don't know what you are talking about.


I am doing a hard ride for 1-2 hours burning between 800-1600 Cal, at most two days in a row. How in the world are you comparing that to the energy needs of people doing over 5000 Cal a day for 3 weeks?


And by the way 400 Cal per hour of carbs is right at the limit of what your body can absorb. So actually TdF riders will not consume much more per hour during a stage.


The big difference is that a TdF rider needs to eat a lot off the bike and struggles to absorb enough energy to be recovered for the next day. While I can just do some chocolate milk afterwards, eat slightly more for the next couple of meals and have plenty of time to recover for the next hard workout.


One bottle per hour is nothing crazy in a cool climate with not much sweating. If it is cold I might only drink half a bottle per hour. And for lower intensity rides in 0C-10C weather I might only take a few sips and come home with the bottle almost full after 1.5 hours. These are large bottles though, about 800 ml.

Carbonfiberboy 

As we used to say, There it is.

Iride01 

I don't think I could stomach 400 Calories of sweetener in my bottles. 200 is about max for me. Normally I use 100 to 150 Calories per bottle.

I use 24 oz bottles and I finish a bottle every 50 minutes in temps around 75° to 90°F.

So we are kind of astounded that anyone puts 400 Calories in their bottles. Most just don't like the sickly sweet taste.

Daevos

I did keto consistently for 9 months last year. Wasn't cycling at the time but in my experience endurance was okay but the intensity had to remain low. That being said, when I developed a goal of completing some 70.3s I noticed my gains were slow and depressing. I began getting 90% of my carbs immediately after a workout, while remaining in ketosis, which helped a bit but my growth was still rather stunted. I abandoned keto in order to increase performance. I do 2-4 week keto stints here and there now that I am cycling and find the experience to be the same. It's doable with low intensity and my recoveries are longer and my gains smaller.

guachi

I wish I could find the scientific study but it was a study about where energy comes from during exercise. Like many exercise studies, it used cyclists on a cycling ergometer. The cyclists exercised at different intensity levels and then measurements were taken. At rest all energy needs were met via free fatty acids and blood glucose. As aerobic intensity increased glycogen and fat usage (I can't remember the exact type of fat but whatever muscular fat is called) both increased as muscles were now having to work. Both kept increasing until a certain point (it was 65% but I can't remember 65% of what - V02 max, lactate threshold, max heart rate, FTP - but it was at a moderate intensity) and after that fat usage actually decreased and carbohydrate usage shot up like a rocket.

So if you were actually interested in burning lots of fat it seems the best way to do it would be to ride at a low-moderate pace as well as get that low-moderate pace as high as possible by, at times, actually consuming carbohydrates and working hard to increase your fitness.

Toadmeister

Well 2 months of Keto FAIL for me Jan-Feb. Net weight loss about zero. I was in ketosis for a couple of weeks here and there but than couldn't sustain it. In hindsight, I was just eating too much in general and the calories overpowered the Ketosis is my theory.

Now that an early March Spring has sprung I am starting to hit the roads and trails and I find I need those carbs. Just bought my first bunch of Bananas since October!

I'm trying Zoom now- it's a phone app/paid service. I like that it sets goals and deals with my psychology, habits, and behavior patterns. I'm eating less fats or heavy meals and am substituting "less calorie dense" foods. I feel better after week 1. Hope to follow this all spring and summer for sure. Cutting back on my portions is a challenge right now but its the right thing to do.

Daevos

Were you using the strips to determine if you were in ketosis? Those were always sporadic for me so I bought a "Keyto" breathalyzer which seemed consistent. That being said, none of it is really relevant if you didn't achieve your end goal. Not being on a keto diet is way more fun anyways.

Toadmeister

I did not as I could always tell when I was in Keto, it was pretty obvious to me (breath, feel it in my muscles & tissues).

I think Keto is a great option for some people and was for me for a time. Like most any diet, once I go off it I will usually put weight back on. So it's not a good long-term plan for me.

Carbonfiberboy 

That's what we used to believe when only gas exchange ratio was used to determine fat burning. Turns out it's more complicated that that. There's an old saw, "fat burns in a carbohydrate flame," which turns out to be true. You have to have carbs to burn fat. It also turns out that for the well-trained athlete, as you go harder, fat burning doesn't drop off like they used to think. In fact at very high intensities it actually increases. Turns out that the way to lose weight is just like we always thought: exercise hard and don't eat too much. Each of these links has a slightly different take on the subject:

https://www.jackkunkel.com/blog/why-.../#.YIg_trVKiUl
https://www.answers.com/Q/What_does_..._flame%27_mean
https://www.trainingpeaks.com/blog/w...carbohydrates/
https://medium.com/fastfitnesstips/m...s-4ea49fd23a85

fooferdoggie 

well not sure what you think plodding is it under 200watts? I cant eat carbs my body hates them and they cause a lot of problems they actually slow me down. So I pretty much run on protein only with veggies a few times a week. even fat does not really do much energy wise for me. on a good day I can average 180 watts for over a hour on a really good day 200 watts. I have ridden 225 miles in a week and I do at least 20 miles a day. I have bonked as I am still learning how many calories I need to eat. Plus protein is slow energy so I have to plan ahead. it is a big learning curve and my body does not go into keitosis even with 2 weeks of no carbs at all.