Real food often has a higher fructose amount, So maybe you are getting closer to 1:1 in your stomach than you think
They market to runners, and runners are:
- More afraid of fructose than non-runner endurance athletes (like cyclists and triathletes)
- Consume fewer carbs per hour on average and therefore aren’t as likely to overwhelm their gut with too much glucose.
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Thank you for the explanation.
Does anyone know if there is actually any physiological difference between 60g of sugar or 30g of maltodextrine + 30g of fructose?
Not that I am aware of. @Dr_Alex_Harrison would be the person to answer
The body has to do a bit of extra work to break down the sugar (sucrose) into glucose & fructose with an enzyme before it can be absorbed. So presumably a little slower.
Turns out that enzyme is not a rate limiting step, so in our body’s, there is effectively no difference.
At least none testable by the most realistic means of testing: how much can be absorbed and utilized hourly at highest tolerable carb intakes.
I still want to spend an hour talking with a dentist or mouth hygiene researcher regarding various carb options and various dental tradeoffs. If anyone here is such a person, DM me!
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Interesting thread. We have been working on creating a sports nutrition brand starting with a carb mix. At the start we figured we would use a 1:0.8 ratio given the latest research and hype around 120g, but before committing we did a survey with 200 local athletes. We found that only 5% were trying to consumer over 90g per hour. So we built an AI to work through the research from the past 15 years and found that to some peoples points in this thread, a 2:1 ratio is actually most optimal when consuming 90g or less per hour.
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How did you define “most optimal” in that context? Or was that what the majority of the research papers on that subject simply used?
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Great question. At a high level, optimal meaning the highest % of carbs ingested gets to your muscles (or in more scientific terms, gets oxidized) and in turn the lowest % gets stuck along the way in your stomach/gut. This came through in the research that showed we should be maximizing our glucose intake first (average max is 60g per hour), then layering the fructose on top of that. So lets say you wanted to ingest 90g per hour. Using 1:0.8 (50g glucose, 40g fructose) you are leaving 10g of glucose whereas 2:1 (60g glucose, 30g fructose) you are maximizing glucose intake.
If you look at the research through the lens of total oxidation RATE, then yes 1:0.8 is better when consuming 120g per hour vs 2:1 at 90g per hour, because inherently you are consuming more carbs to then get oxidized. But if you look at the oxidation rate PERCENTAGE, the results are different. 2:1 you oxidize a higher % of the carbs ingested, but only when consuming 90g or less - which is relevant because thats what we found the typical endurance athlete is targeting realistically. We do a custom mix for the athletes who are trying to target 100g+ per hour.
Here is our website if interested. www.solofuel.ca
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Pretty sure you’re explaining this a little wrong.
Oxidized / used - yes, but the issue with higher concentrations of fructose isn’t that it isn’t absorbed and that it gets stuck in your stomach / gut. It gets absorbed, but not necessarily transformed (processed by the liver) into “usable” energy. It ends up getting stored when it isn’t oxidized.
That isn’t necessarily a problem though - depends on the workout, the individual, total energy balance, need to restore glygogen levels, and all that. If someone’s doing a lot of volume, it could still be a benefit even if it isn’t oxidized during the current workout.
Generally I agree though, shorter workouts or workouts requiring less fuel, you’re probably better off with a 2:1, longer workouts or workouts requiring more fueling, or where you need more glycogen repletion, you’re probably better off with 1:.8
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Yes that’s exactly right. Apologies if my terminology on the absorption piece was misleading but I totally agree with your summary! The key thing is there is a place for both ratio’s, and to your point it really depends on the athlete, their needs and their goals.
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there is some level of difference. Sugar/ sucrose is a 1:1 glucose-fructose, maltodextrin is 100% glucose. So you would be changing the ratio of glucose to fructose by running the maltodextrin. There is however another small factor, osmolarity of the solution which is governed by the number of molecules per liter. Maltodextrin is a long chain molecule so has a low osmolarity in solution. Therefore the same number of grams of sugar will have a higher osmolarity and thus it can have a negative impact on how your gut reacts to it. That is the main reason to use maltodextrin to get more carbs into you for less gastric stress.
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Wasn’t the excess carb intake for quicker replenishment of your carb stores after your workout (“getting ahead of recovery”)?
Yes. I thought that the 1:0.8 recommendation came as a result of people ingesting more than 90 g/h. Or is that false?
Yes! Thats true. The problem we saw after doing primary research with 200 local cyclists and runners was that in an ideal world they understood consuming over 90g per hour is best for performance, but a very small amount of athletes were actually doing it due to a number of reasons like consumption fatigue and cost. Over 80% were instead trying to target 60-90g often using products that were closer to a 1:0.8 ratio. So that’s why we are starting with a 2:1 mix to support that market of athletes (<90g per hour), and we are also doing it in a low-cost way.
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I think I’m missing something - At what point are people struggling with regular sugar?
I’m putting 4x25ml scoops of sugar into a 750ml bidon and getting through it fine. Might need to keep shaking it up to keep it solvent. Is it the second, third, fourth bottle?
Gut distress. I tried normal table sugar and had horrible gut distress. But for me, using a mix of maltodextrine and fructose I can handle up to 120g per hour just fine.
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The ability tolerate and oxidise cabrohydrate varies greatly between individuals. If that works for you, I say, keep at it!
Regular table sugar consists of 50% fructose and 50% glucose, which is pretty close to the 1:08 ratio. So you are doing what @Connor_Willson is indicating since you are consuming > 90 g /hr (assuming you are going through 1 bottle per hour?).
(4x 25ml of table sugar = 100 g)
I’ve just reviewed a very recent paper by Dr. Podlogar and colleagues. It’s not been published yet but you can find the pre-print here if you are interested in reading it.
We already know that body mass influences how many calories we expend/ need. However, the current guidelines do not consider body mass for carbohydrate intake during exercise.
However, the results of this study bring into question the current reccomendations.
The results indicate that the amount of carbohydrates we can use on the bike is influenced by body mass. The largest individual in the study had peak exogenous glucose oxidation rates of 90g/hr which contradicts our current understanding that we have a fixed maximum glucose absorption rate of 60g/ hr, irrespective of body mass.
(**exogenous just means the carbohydrate that are ingested through food or drink as opposed to stored glycogen).
All that is to say, there is likely much more variation in our ability to tolerate and oxidise carbohydrate than we originally thought.
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Thanks Sarah
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I struggle with table sugar after a couple of hours. Malto and fructose are more tolerable, for me.
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