What to Eat for T100? Your Guide to Fueling Before, During and After the Race
What separates a good T100 day from one that falls apart on the run is rarely the swim, the bike or the run in isolation. It's what an athlete puts in their body around all three. A full T100 is 2km swim, 80km bike and 18km run — 100km of racing that will have most age-groupers out on course for somewhere between three and six-plus hours. Every one of those hours needs deliberate fuelling. Get it right and the run leg feels controlled. Get it wrong and the last 5km becomes a walk while wondering what happened.
T100 Dubai lands at Al Mamzar from 13–15 November 2026, with water sitting around 28–29°C and air in the high twenties to low thirties. That heat raises sweat rate and carb burn at the same time, which is exactly the combination that catches athletes out. The advice below leans toward GU, Maurten and Precision Fuel & Hydration — worth saying upfront, since that's what GRIT+TONIC stocks and what its team trusts on race morning.
In this guide:
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What to eat in race week and on T100 morning
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How to fuel a 100km day leg by leg — swim, bike, run
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Hydration and electrolytes for racing in Dubai heat
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Recovery, and where to test the whole plan before race day
Why T100 Fuelling Is Its Own Problem to Solve
A sprint triathlon barely needs a fuelling plan. A full T100 is a different sport. It covers four to five times the distance of a sprint at a pace held for hours, in a climate that pulls far more fluid and sodium out of the body than a cooler-weather race would. Treated like an oversized Olympic-distance effort, it runs out of carbohydrate on the bike, and the run leg turns into survival rather than racing.
Race Week: Building the Glycogen Bank
Three to Two Days Out
Carbohydrate intake goes up, fibre and fat come down. Rice, pasta, potatoes, white bread, ripe fruit — boring, reliable carbs the gut already knows. This is also where a product like Maurten Drink Mix 320 earns its place: a clean, measurable way to hit a carb target without forcing down another plate of pasta. Best sipped alongside meals rather than instead of them.
The Night Before
Dinner should be early, familiar and carb-forward, with moderate protein and low fat and fibre. Nothing new, nothing spicy, nothing that hasn't already been raced on. Water and a low-dose electrolyte drink through the evening work better than a large volume in one go.
T100 Morning
Breakfast 2.5–3 hours before the wave start: oats with banana and honey, or toast with peanut butter and a boiled egg. Thirty to sixty minutes before the swim, a GU Original Energy Gel or a GU Roctane Gel with a little water is a reliable top-up, alongside an electrolyte drink sipped well before the start pen — in 28–29°C water and warm air, the goal is to enter the swim already topped up, not catching up.
Fuelling the 100km: Leg by Leg
The Swim (2km)
Nothing to fuel here. The job on the swim is to arrive at T1 already hydrated, not dehydrated from nerves and heat before the race has even started.
The Bike (80km)
The bike leg is where most race nutrition happens — the stomach handles volume far better seated than it will on the run. For an effort this long, the target is 60–90g of carbohydrate per hour, and this is where Maurten and GU earn their keep, both built around carb loads and delivery the gut can actually absorb at that rate.
Example bike fuelling plan for T100:
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Start: bottle of Maurten Drink Mix 160 on the aero bars
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Every 20 minutes: alternate a Maurten Gel 100 with a GU Liquid Energy Gel
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Every 45–60 minutes: a few GU Hydration Tabs mixed into the second bottle
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Last 15km: a caffeinated GU Roctane Gel to start waking the legs up for T2
The Run (18km)
By the run, heat and accumulated fatigue are working against the body, so simple wins: gels, chews, and an electrolyte drink at aid stations where it's offered. Carbohydrate intake stays at 30–60g per hour, in smaller, more frequent hits than on the bike. GU Chews earn their place on the bike, but for the run SaltStick Fast Chews are the better call — built for electrolyte replacement rather than a carb hit, which suits legs that are already fatigued and overheating. Pair a pack of those through the middle of the run with a caffeinated Roctane Gel around the 12–14km mark — close enough to the finish to push, far enough out to still matter.
Hydration and Electrolytes: Where Dubai Heat Actually Bites
This is the part most age-groupers underestimate, and it's worth explaining rather than just naming a favourite brand. Sweat sodium loss varies enormously between athletes — some lose close to nothing, others lose enough to cramp badly on a warm day. Precision Fuel & Hydration built its whole product range around that difference, with PH 500, PH 1000 and PH 1500 electrolyte tabs formulated for light, moderate and heavy sweat losses. Working out which one fits is best done before race week, not on the start line — a sweat test, or even just tracking how salty kit looks after a long training ride in this heat, tells more than guessing.
As a baseline for T100 Dubai conditions, 500–800ml of fluid per hour is a reasonable range depending on body size and sweat rate, with electrolytes in every bottle rather than plain water alone. Plain water on a hot 100km day dilutes whatever sodium is left rather than replacing what's being lost.
Post-Race Recovery
Within 30–60 minutes of crossing the line, a 3:1 or 4:1 carbohydrate-to-protein hit does the most good — a GU Roctane Protein Recovery Drink Mix or a recovery bar with some fruit both work well when appetite hasn't come back yet. Electrolytes should keep going for the rest of the day; most athletes underestimate how dehydrated a hot T100 leaves them, and the damage shows up as a wrecked next two days rather than anything felt at the finish line. A proper meal with carbs, lean protein and vegetables later that evening finishes the job.
The Best Way to Test the Plan: Race the Mamzar Triathlon First
Every fuelling plan sounds good on paper until it meets an actual race morning. That's exactly what the GRIT+TONIC.com Mamzar Triathlon is for. It's held at Mamzar Beach — the same stretch of coastline T100 Dubai is racing this year — on 25th October 2026, three weeks out from T100 weekend, in the same heat and the same water. Racing the Sprint or Olympic distance there works as a full dress rehearsal: same gels, same electrolyte strength, same morning routine, so the only thing left to figure out on T100 day is pacing.
Common Fuelling Mistakes on Race Day
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Skipping breakfast out of nerves
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Trying a new gel, drink mix or electrolyte tab for the first time on race morning
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Drinking only water in Dubai heat instead of an electrolyte mix
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Under-fuelling the bike while feeling fine early, then paying for it on the run
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Guessing sweat sodium needs instead of testing them beforehand
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Stopping fuelling once the finish is in sight
Shop the T100 Fuel Kit
Conclusion
T100 rewards athletes who treat nutrition as a fourth discipline, not an afterthought. Building the carb bank in race week, fuelling the bike properly, matching electrolytes to actual sweat loss, and using the Mamzar Triathlon to rehearse the whole plan — get that right, and the only surprise on 13–15 November should be the finish time.
The GRIT+TONIC team is in-store beforehand for anyone building their own race-day kit.
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