Three disciplines. One fuelling
system. Zero compromises.
Triathlon nutrition has to survive the bike and still work
on the run. The truefuels system is built for that transition.
Triathlon nutrition has to survive
the bike and still work on the
run. The truefuels system is
built for that transition.
Informed Sport certified ·
Built by Alistair Brownlee ·
4.86★ (200+ reviews)
60–90% of endurance athletes underfuel.
The wall, cramp and overheating are fuelling failures — not fitness failures.
Hitting the Wall
The Ironman bike leg is 180km of glycogen expenditure. Athletes who under-fuel on the bike are walking the run — not because their fitness failed, but because their fuelling did.
Energy Gels
40g of fast carbohydrates per gel — start at 30–40g carbs/hr in training, build 10–15g per week, arrive at race day absorbing 80–90g/hr.
Shop NowCramps
Cramping on the run almost always starts on the bike. Sustained sweat loss over 4–6 hours depletes sodium and potassium faster than most athletes replace — by the time you feel it, the deficit has been building for hours.
Electrolytes
390mg of sodium per sachet — matched to what your body actually loses in sweat, not inflated. Your hydration stays on track, from T1 to the finish line.
Shop NowHeat
Ironman and 70.3 events in warm climates mean core temperature is a performance variable from T1. Three disciplines in the heat — it compounds with every transition.
CoreCtrl
4,000mg of L-Taurine per sachet — taken daily for 8 days before your event to help your body handle heat under load. Stay in control when the conditions turn against you.
Shop NowYour Race Fuelling Calculator
Enter your race details and get a personalised gel and electrolyte plan.
Products & Bundles
Start with a bundle or build your own stack. Bundles save you vs buying separately.
RACE READY SYSTEM
40× Energy Gels + 20× Electrolyte sachets + 8× CoreCtrl sachets + FREE truefuels bottle
TRAINING BUNDLE
20× Energy Gels (mixed low + high salt) + 20× Electrolyte sachets
Gel — Low Salt (0.25g)
40g carbs · 0.25g salt · cool races · sprint/Olympic
Gel — High Salt (1g)
40g carbs · 1g salt · Ironman/70.3 · warm conditions · heavy sweaters
Electrolytes
400mg sodium · 150mg potassium · 25mg magnesium
CoreCtrl™
4,000mg taurine · Kona-tested · bike-to-run heat management
The Science
Built by Alistair Brownlee from real race experience. Each product solves one problem. All three stack together.
Energy Gels
Glucose uses SGLT1. Fructose uses GLUT5. The 1:1 ratio activates both transport pathways simultaneously — supporting absorption of up to 1.75g/min compared to 1g/min from glucose alone. Over a 4-hour bike leg, that's the equivalent of three extra gels worth of available energy — energy that decides whether you run the marathon or walk it. Start at 30–40g/hr and build 10–15g per week. The gut adapts to what you train it to handle.
Electrolytes
390mg sodium, 150mg potassium, 25mg magnesium per sachet — matched to sweat loss during endurance exercise. Not just for race day. The daily habit that helps keep neuromuscular function intact across a full training week — and helps prevent the compounding deficit that causes cramps on the run, built up silently over hours on the bike.
CoreCtrl
4,000mg of L-Taurine, with potassium and magnesium to help support neuromuscular signalling under fatigue. Taken daily in training, not just before race day. This is how you arrive at T2 with your reserves intact — and finish the run instead of surviving it.
"Kona taught me that heat and fuelling are the race within the race. We built truefuels to solve both."
— Alistair Brownlee, 2x Olympic Champion, truefuels co-founder
Alistair built truefuels because no existing product met the demands of elite triathlon — heat, duration, GI stress all at once. Tested by Alistair and 50+ elite athletes.
Real fuel. Real sessions.
★★★★★ 4.86 from 200+ verified athletes
I finally found race-day fuel that works for me, as I sweat heavily and lose a lot of sodium. It's so easy to mix with some water in a bottle and carry on my bike. It helped me achieve a 21-minute PB in a Half-Ironman race this summer.
Fuelled my way to Kona Racing Ironman Da Nang in 35-degree heat with a Kona slot on the line, nutrition couldn’t be an afterthought. The truefuels Race Ready System was the most dialled-in I’ve ever felt across a full Ironman. The 1:1 glucose-to-fructose ratio meant I was actually absorbing the fuel, not just stomaching it. The high-sodium gel handled hydration and carbs in one — no salt tabs, no complexity. And crucially, it never got too sweet, so I kept fuelling confidently right through the marathon. crossed the line strong. Kona slot secured. truefuels was a big part of that. Alan Conway | AG 40–44 | Ironman Da Nang | Kona Qualifier
I have used sports gels for triathlon events for some years and always found my tolerance poor often getting bloating and GI issues. I have so far only used Truefuel gels (0.25Na/ 1.0Na) to complete my last few weeks of training in advance of the Swansea Ironman 70.3 this coming weekend. But so far no GI issues and the gels definitely help keep performance levels up over the whole session. I’ll post another review after the event this weekend.
During last weekends Bath Beat Cross Country marathon, I hit the wall around 18-19 miles in, I was ready to through the towel in, my legs had had it,(the temperature was 22 degrees) I was running this after running the Paris Marathon less than two weeks earlier, I drank some of the true fuels electrolytes followed by your energy gel with 1g, within 4-5 min I really started to feel better and went on to finish the marathon feeling good at the finish! I normally use SiS , but will be using Truefuel from now on!! And will be taking these to the Ironman world championships in Kona in October.
Get a personalised triathlon fuel plan — Ironman, 70.3, Olympic or Sprint
Personalised gel and electrolyte plan based on your race distance, conditions and target time.
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Frequently Asked Questions
8–10 gels on the bike + 2–3 on the run. Start fuelling 20 min into the bike, every 30–35 min. Use the calculator.
2–3 gels for the run, 1–2 electrolyte sachets, CoreCtrl if racing in heat. Set gels in race belt at T2.
1:1 glucose:fructose ratio uses two intestinal transport pathways. Take gels with water (not sports drink). Practise exact race-day fuelling in training.
Nothing on swim. First gel 20 min into bike, every 30–35 min on bike. Gel at T2. Every 35–40 min on run with electrolytes.
40 gels + 20 electrolyte sachets + 8 CoreCtrl + FREE bottle at £169.95.
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