Performance Gel Stackability Explainer
Author: Alistair Brownlee
truefuels performance gel - the simple fueling for any session
After years of racing, training, and experimenting with every sports nutrition product available, I kept running into the same problem: nothing really worked for everyone.
Some gels were too salty. Some had barely any salt. Some had carbs but didn’t sit right.
So we built truefuels — a simpler, cleaner solution that lets you adjust what you need depending on the session, the conditions, and your body.
One Fuel. Two Salt Options. Stack as Needed.
Our performance gels are all about carbs and salt because those are the two things your body needs most when training hard.
Every gel has 40g of fast-absorbing carbs, and the two varitaions have different amounts of Salt:
| Name | Carbs | Salt |
|---|---|---|
| 40 / 0.25 | 40g | 250mg |
| 40 / 1.0 | 40g | 1g |
That’s it.
You just combine them based on what the session demands. Cold, easy ride? One 40 / 0.25 might do the job. Racing in the heat? You might need a mix — say, two 40 / 1.0s and one 40 / 0.25 per hour.
How to Stack for Different Sessions
Here’s a quick guide to get you started. It’s not a rigid formula — just a helpful framework to think about carbs per hour and salt per hour, depending on how hard you’re going and how much you’re sweating.
| Combo (per hour) | Carbs | Salt | Good For |
|---|---|---|---|
| 1× 40 / 0.25 | 40g | 250mg | Low-intensity (Z1/Z2), cold weather, short sessions (1 hour or less) |
| 1× 40 / 1.0 | 40g | 1g | Moderate sweat loss or short sessions in heat (Z1/Z2 - 1 hour or less) |
| 2× 40 / 0.25 | 80g | 500mg | Long endurance sessions in cool conditions |
| 1× 40 / 1.0 + 1× 40 / 0.25 | 80g | 1.25g | Warmer temps, moderate intensity |
| 2× 40 / 1.0 | 80g | 2g | Hot weather, high intensity |
| 2× 40 / 1.0 + 1× 40 / 0.25 | 120g | 2.25g | Long, hard sessions or races in serious heat |
| 3× 40 / 1.0 | 120g | 3g | Extreme heat, heavy sweat rate, high intensity |
| 3× 40 / 0.25 | 120g | 750mg | High carb needs, low salt needs (e.g. cold conditions, low sweat rate) |
A Few Tips
Carbs: Most people do well on 60–100g/hr for long efforts. Top-end work can go to 120g/hr.
Salt: If you’re a salty sweater or training in heat, you’ll need more sodium. For most people a sodium loss of around 1g/litre (2.5g/l Salt) is a good guide but it can range from 200mg to over 1500mg per hour, individual variation is significant. If you see evidence of salt on your clothes during exercise, you are probably a salty sweater!
Mix and match: That’s why we kept it simple — just stack the gels to hit your numbers.
Why We Did It This Way
There are so many products out there that try to be everything to everyone. We wanted to keep things simple — clean ingredients, no fillers, no overcomplication.
The 40 / 0.25 and 40 / 1.0 give you flexibility without needing a spreadsheet or a science degree.
Just grab what you need and get out the door.
*Barnes KA, Anderson ML, Stofan JR, Dalrymple KJ, Reimel AJ, Roberts TJ, Randell RK, Ungaro CT, Baker LB. Normative data for sweating rate, sweat sodium concentration, and sweat sodium loss in athletes: An update and analysis by sport. J Sports Sci. 2019 Oct;37(20):2356-2366.