GhostRider62

Because

1. Excessive glucose would be counterproductive to what one would be trying to achieve metabolically on an endurance ride.

2. You'll need a lot of toilet paper or nappies to wipe the puke on long rides.

Replacing half the calories is usually a good number,

burnthesheep

Another mistake lots of joes make is the assumption of how much fat adapted they are and at what power output that fat/carb contribution actually does bias towards the fat. In other words, they're likely burning more carb than fat at a lot lower power level than they're assuming.

GhostRider62

It isn't easy to measure. One can estimate VLAmax by protocol and taking blood lactate. Or a more fun way is to take a long ride at about 1.5-1.8 lactate or about the high end of Z2 and don't eat. When you bonk, back estimate the percentage (assumes you have a power meter). Riders who are not fit go glycolic almost immediately. This is in Physio and Coach Alan Couzens wheelhouse. At the other extreme, riders who think they can consume 500-600 calories per hour probably have not done a really long ride.

ZHVelo

1. This is completely arbitrary. Do you know what is excessive for you? Certainly not for others.

2. Speak for yourself lol.

Carbonfiberboy 

We await the results of your experiment with consuming 480 kCal/hour on any hilly ride over 5 hours. That 50% rec is not arbitrary at all.

GhostRider62

says the person who thinks eating 480 calories per hour on a long ride is easy. Long races are partly a digestion competition, especially for those with a high VLa Max

ZHVelo

I have already successfully tested it over a three hour ride where the middle hour was sweet spot. I did 90-120-90 without issue and felt much better after the ride than I usually do when I eat (too) little. I also tested 90/hour over a 4 hour ride (which was above 50%). I am not a racer, much less a pro, and I haven't even tested digestion all that much (yet). I absolutely do not see why you need to make blanket statement when digestion is so individual and trainable and people should test it for themselves. Also, I never said everyone should do it or that it is easy, my why not was aimed at your absolute statement. It is almost as if you completely ignored the "Of course you may not tolerate that, but that is a separate issue." part of my reply to you.

MinnMan

This. Lots of posts here seem to assume that folks are perfectly fat adapted as if it's an all or nothing "metabolic switch".

GhostRider62

For most riders, it doesn't matter really. Most riders do rides under 3-4 hours and those can be fueled easily. But for Ironmen or ultra endurance riders, it is not possible to fully keep glycogen stores topped up unless pace is reduced OR one can burn more fat percentage wise.

When I was more able to burn fat and could have been called fat adapted, I could ride seemingly forever. Now that I eat a little more carb, my FTP is higher but my endurance is less. There is a tradeoff on a continuum, and as you say, it isn't like a light switch.

https://alancouzens.com/blog/improvi..._burning2.html

MinnMan

Interesting point, but I'm not sure where the cutoff would be and if it is the same for everybody, depending on their training. I've never been deliberately fat adapted and I used to be a total carboholic. However, when I am/was properly trained (i.e., had lots of miles in my legs), I have had no trouble doing centuries or up to 150 miles without fading at the end - that is, 5-8 hour rides. That's not ultra-endurance, but for me, the window is definitely greater than 3-4 hours. Without "fat adaptation". I do not favor rides longer than about 7 hours for other reasons.

GhostRider62

Doing rides of that length in zone 2 automatically gets you burning a lot of fat. The benefits to timing of eating and exercise can have more benefits.

What I find interesting is looking at the training intensity and duration of professionals during the off season or "base" period.......early in the season. Lots of hours at fairly low intensity.

https://physoc.onlinelibrary.wiley.c....1113/JP280748

MinnMan

Well, there's no question that I lose weight when I get into the swing of things and do a century or century+ every Saturday, so surely I'm burning fat. But I thought that you were earlier making a distinction between "I did a long ride and so I burned some fat" and "I'm fat-adapted, so I'm better-able to do long rides"

And those centuries are commonly well above zone 2, btw.

GrainBrain

Ah man I didn't see this thread till now. I'll checkout the link and videos for sure. Here's my favorite recipe for rice cakes, they're super good!

https://www.efprocycling.com/tips-re...ke-rice-cakes/

I'm also a huge fan of maltodextrin, specifically HEED by Hammer.
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PeteHski

I find the longer the ride, the harder it is to keep slamming down the carbs at that kind of pace. My event rides are typically around 5-9 hours and it really gets hard to force down the carbs after the first few hours. Moving from solids to gels and liquid helps, but I usually struggle to average more than 60g / hour over say 6 hours. But I don't bonk at that level, so it's enough for me. I'm not at all surprised MVDP is taking in double what I would given his power output! As you say it is trainable to some extent and I know the Trainer Road guys are quite big on increasing carb intake for endurance. I've certainly tried it and take in what I can tolerate on events.

The other big factor is intensity. The harder you are riding, the harder it is to consume carbs. For example riding at a leisurely pace I could eat pretty much anything I wanted. But ramp the pace up to tempo for several hours and it gets much harder to fuel. I don't think in reality many ordinary guys could replicate MVDPs fuel intake while riding at the same relative intensity. But you can certainly copy the principle.

ZHVelo

This is really what I wanted to say. You may not get to 120g/hour, but why not try and just see to where you get.

And agree, I mean if it were impossible even at rest, you couldn't smash down any large carb-heavy meal without getting problems (and maybe some people do get problems). One needs to figure out how one can keep the intake up with increasing intensity.

PeteHski

Yeah, it's very individual but also trainable. You just have to find the right fuel mix (again very individual) and experiment a little. On a long hard event ride I usually start with a bar (40g) plus 1 bottle (20g) in the first hour, same again hour 2 and then in the 3rd hour start replacing bars with gels at around 2 per hour (22g each). I also try to keep chipping away at a bar or two more if it's a 5+ hour ride. As I say, I usually end up averaging around 60g of carbs per hour over 5+ hours.

GhostRider62

Well above Zone 2 is what? Zone 4? Even if you mean Zone 3, you are very fit to average that for 100 miles. Not many can.

Pros are barely out of Zone 1 into one 2 sitting in during easy pace sections of grand tour stages, so, it is easy to consume a lot of carbs. During climbs or breaks, it is a different story for sure. They have great metabolic flexibility (switch between fat, lactate, and glycogen for instance). Nonetheless, they are not eating on the bike for today's race but for the tomorrows races because it can take 36+ hours to completely refuel when depleted. Most of us do not have that concern. There has been some recent research showing up to 120 grams per hour are possible and that an even higher percentage of fructose in the mix is tolerable with specific training of the gut. I am experimenting with a higher intake using a commericlal product made mostly of cyclic dextrin and I am adding fructose. So far, it looks like it is far more tolerable than what I used in the past. So, old dogs might be able to learn a few new tricks. I'll find out on a hot 400 or 600K