DIY Precision PF 30: replace the fuel, not the sweat test

Precision Fuel & Hydration's core product isn't the gel — it's the individualized sweat test. They measure your per-hour sodium loss rate in a lab-like setup and then prescribe an electrolyte protocol tailored to that specific number. Their gels are intentionally sodium-free so you can pair them with their PH electrolyte tabs at whatever dose your physiology actually needs. The business model is consultation-plus-product, and the consultation is the harder thing to copy.

What DIY can replicate: the gel itself. PF 30 is 30g of carbs at a 2:1 maltodextrin-to-fructose ratio in a 51g-per-serving gel format, with zero sodium. Nothing exotic in the formulation; the macros can be reproduced at home for roughly 50¢ per matched dose instead of $2.75. What DIY can't replicate: knowing whether your sweat sodium is 600mg per hour or 1800mg per hour. Those two numbers imply wildly different fueling and drinking strategies in a hot race, and no amount of DIY effort surfaces them. The sweat test does.

Making a gel at home is trickier than making a drink mix, and this is where DIY fidelity falls off. Three practical options. A concentrated flask — 30g of DIY maltodextrin-plus-fructose dissolved in roughly 100ml of water, sipped in 100-150ml pulls — is the cleanest approach and keeps the formula identical. A home paste at equal parts maltodextrin and water plus some fructose gets a gel-like consistency but is sticky, finicky, and doesn't keep. A honey or maple syrup base gets an automatic 1:1 glucose-fructose ratio with a different taste and a friendlier viscosity, but the macros drift slightly from PF 30's specs.

Where Precision's decoupling philosophy is actually sound: they're right that sodium and carbohydrate needs are governed by different physiology. Sodium needs scale with sweat rate and duration; carbohydrate absorption is capped by fixed transporter biology. Locking them together in one product forces compromise in one direction or the other. A sodium-free gel plus a separately-dosed electrolyte tab lets each lever move independently, and that design principle applies just as well to DIY: pair your DIY gel with whatever sodium source your sweat-test result calls for.

Precision sells something you can't mix at home: a specific number for your per-hour sodium loss. Once that number exists — whether from Precision, Levelen, or another sweat-test provider — DIY fuel becomes the cheap way to execute your personalized plan forever. Before that number exists, optimizing 50¢ per gel is the wrong problem to be solving.