SiS 5:4 Maltodextrin to Fructose
Just when you thought it was safe to have a gel, SiS come and spoil your party. Like you, I have been blindly taking as true the not-so-old adage that “glucose:fructose ratios need to be 2:1 to maximise how your gut absorbs carbs”.
Well, 2:1 ratios are only able to allow 62% of ingested carbs to be oxidised. Change the ratio of maltodextrin:fructose to 5:4 and that’s boosted to 74%…a 20% increase.
These new ratios are contained in SiS’s reformulated Beta Fuel.
Here is the research by O’Brien, Stannard et al which concludes:
Enhanced high-intensity endurance performance with a 0.8 ratio fructose-maltodextrin-glucose drink is characterized by higher exogenous-CHO oxidation efficiency and reduced endogenous-CHO oxidation.
Sis sell the stuff in 3 formats
- Energy Drink Powder – to minimise GI distress
- Gels – with nootropics for improved cognitive function
- Chew bars – an easy-to-chew formula
My Personal Take
If you are a high-level athlete competing on the edge this will probably make a difference. To you and me …less so.
If we are competing in Olympic distance events or shorter I guess there’s no point either
That said I didn’t know that energy drink powders aided GI distress and might switch to that next year when my gels have run out. I do get GI distress if I fuel only with gels and my current strategy is to alternate them with something solid, which seems to help.
Check Out How Much It Costs
It’s not crazily expensive and comes in at £2 a gel, probably about $/Eu2.50/gel
- Buy at: Amazon.co.uk – SiS Store
- Buy at: Amazon.de
- Buy at: Amazon.com – SiS Store
Last Updated on 25 January 2026 by the5krunner
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tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors. ID
So SIS are now admitting that all their marketing about 2:1 being optimal was bollocks!
Wonder what the magic ratio will be next time they decide they need to increase sales 😉
Golden ratio? 😂