80-100 grams per 750mL bottle?

Hi, all.

Maurten, NeverSecond, and SiS BetaFuel all offer a similar product: 80-90 grams of carbs in 500mL of water with the claim (oversimplified) they will not need to draw extra water into your gut hence, a way to curb gut distress while getting a lot of fuel. They often reference being an isotonic solution or the product’s pH. SiS just looks like 1:0.8 malot:fructose ratio whereas Maurten references their proprietary hydrogel as a component of its success.

How important is having a 6-8% solution in the bottle? Should osmolality be a concern?

Does getting 80-90 grams of carbs into a bottle using another product like First Endurance EFS ultimately the same thing? They have a more diluted recommendation which is right in that 6-8% range. If I mix EFS per the recommended, it will be hard to get 80-90 grams of carb per 750mL bottle on the bike without carrying a lot of water to go along with it.

Trying to nail down my ironman nutrition strategy. Thanks in advance.

There are thousands of posts on this topic already. I did a search on “osmolality” that should help. My personal mix is 60g maltodextrin to 30g fructose, but there are lots of other opinions and recipes in the topics below.


Cluster Dextrin


Total grams per hour, and grams per liter are the king and queen of “what matters” to your gut.

Companies get away with these claims because most folks aren’t actually pushing the upper limits of hourly carb consumption.

And most folks won’t drink all 80-90g in 500mL all in one guzzle.

If that’s all you consume, and you consume it sip by sip, you’ll probably be fine because you’re well shy of gut upper limits of absolute hourly carb consumption rates.

If you were to push for a more optimal 90-120g carbs per hour, you’d need more fluid to get it to play nice with your gut.

80-90g/500mL = 16-18% concentration. That’s high.

Not that important 95% of the time. 8-14% works for a lot of folks. 8-12% is better if trying to maximize carb intake and not risk gut issues.

Minimal, but maybe yes. The good news is, most companies focus on this way more than they should already so if you’re doing the other things right, you’ll be fine from an osmolarity perspective, while using their products.

No. They have some complex carbs included, IIRC. It won’t play nice for some folks at 90g/hr, and especially if only consumed with 500mL.

You may be part of the 5% of the time that 8-14% isn’t a good recommendation. 8-12% early on bike, and 6-10% late in bike and during run is probably wiser, unless sweating is minimal because it’s cool out.