Some water does travel along with the glucose/fructose and electrolyte active transporters. In my experience (n=1), GI distress has always been caused by not enough water in my SI. Anytime it’s happened, drinking a bottle of water immediately made it go away. In my opinion, it’s not caused by too much glucose in the SI (because that’s somewhat throttled by the SI anyways), but by too high an osmolarity in the SI caused by lack of water. Also keep in mind, when talking osmolarity you have to count everything in your drink, electrolytes too.
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Thank you! I was essentially trying to confirm if I understand the mechanisms correctly and tease out the reason for GI distress. If it is caused by water travelling in the wrong direction (body to stomach or SI) or by too much drink in the stomach (either because it had to be diluted for it was of a too high osmolarity or because it is waiting there until it can be continue to SI). I think you say it is the former.
And I know I was only focused on energy absorption. Electrolytes are not my concern outside of the hottest days as I don’t sweat out almost any salt. Water is obvious and I drink as much as I can which usually works ok. Moreover, I almost don’t race and certainly not for long durations.
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To be more specific, I don’t believe it’s just water going the wrong direction. It’s prolonged time of water running the wrong direction and you becoming dehydrated and the SI needs more water. It’s at that point in my experience that I have had GI distress. How long does it take? Depends on how hydrated you are at the start and how much the environmental conditions are reducing the water volume in your blood (sweating).
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I added SIS strawberry lime tab to that exact fructose and carbo gain. I had the entire bottle gone in 30 mins. That was sooo dang delicious. I could easily get in 180 g of carbs per hour with that recipe.
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Thanks for the link, this is cool!
Here’s my isotonic recipe using Gatorade / CarboGain mix and US measurements:
18oz water
2/3 scoop Gatorade mix
1/3 cup Maltodextrin
Mixed in bulk in a drink pitcher:
1 gal water
1 1/3 cup Gatorade powder
2 1/3 cup Maltodextrin
On the most recent podcast they mention that new studies are suggesting that a 1:1 or 1:0.8 mix is more beneficial than a 2:1 mix. Has any determined exactly what the mix in Gatorade is? I’d like to try out a 1:1 blend.
You would be correct! Folks need to focus less on isotonic solution and just meeting the following needs:
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Carb needs per hour
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Sodium needs per hour.
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Fluid needs per hour.
Doing so with closer to a net 8-18% solution is probably more optimal in most conditions. Maybe 12-18% in cooler conditions, and 8-12% in hotter conditions. I generally just target 12-14% personally unless I’m at the end of a 4-6-hr ride and dehydrated, in which case I’ll move it down to 8-10%.
This post and my others below it in the same thread may be informative.
I discuss much of this at length, ICYMI.
I think they may be citing my book when they make these quotes on the podcast but I’m not sure. Haven’t listened yet. I know they had cited it in the past, but perhaps they’re citing the Gonzalez review. I need to go listen!
Gatorade is hard to know. Sucrose is first ingredient. Dextrose is next (ie. glucose outside the body). If it’s 95% sucrose and 5% dextrose, it could be quite optimal. I doubt that though. Gatorade has touted 2:1 ratio for a long time. It’s probably close to 1 sucrose : 1 glucose, which gives a 2:1 gluc:fruc ratio.
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Anyone have amazon links to what to buy?
Seems like the current thinking his shifted to 1:1 glucose to fructose aka sucrose, aka table sugar.
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I have done 3h and 4h upper end z2 rides with table sugar/Torq energy powder to taste/0,5 tsp of salt per bottle. 90-100g carbs/hr. Seems to be working just fine.
Thanks @Dr_Alex_Harrison, this will save me a pretty penny in the long run 
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From my post here: At-Home Hydration/Nutrition for an idiot: Triathlon Forum: Slowtwitch Forums
Zefal Magnum Bottles (32oz)
Additional Universal Bottle Mount
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Thanks for this.
I’ve been experimenting with mixing my own fuel for the last few months, to great success so far. I recently purchased a big bag of Sodium Citrate so am now looking to incorporate that, but am a bit lost on how much to use.
I’m mixing malto + water in a 750ml bottle for trainer rides. How much sodium citrate would I be looking to use in 750ml, if I go through the bottle in about 1h15m? Would 1 tsp be about right, if I’m looking to get roughly 1,000mg of sodium per hour?
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Yep! Bingo.
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What’s the serving size for sodium citrate?
My bag didn’t have a measurement
I think 1 tsp = 1000 mg
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I tried doing the sugar and Gatorade but I could not handle how sweet it was. Can I replace the sugar with Maltodextrin? And if so what would the ratio be?
I was showing 1/3 teaspoon being 600mg.
Thanks, all stuff ordered.
For table salt, that’s pretty close. For sodium citrate, there is about half the sodium per tsp, as for table salt.
Clarifying: Sodium Citrate has about 1000mg sodium per tsp. Table salt (NaCl) is about 2000mg sodium per tsp.
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Thanks
