Triathlon Nutrition Hub – Fuel for Swim, Bike & Run
Quick Triathlon Fuelling Guide
Use this comparison as a starting point, then practise your own plan. Hammer’s approach is to use the minimum effective fuel, separate fluid from calories where useful, and adjust electrolytes for conditions
| Distance | Fuel | Fluid & electrolytes | Recovery |
|---|---|---|---|
| Sprint | HEED or Hammer Gel if needed | Drink to thirst; Endurolytes as practised | Recoverite or a balanced meal |
| Olympic | HEED and/or Hammer Gel | Practised fluid range; Endurolytes as needed | Recoverite or a balanced meal |
| 70.3 | Perpetuem first; Gel for the run | Fluid and Endurolytes adjusted to conditions | Recoverite |
| Iron distance | Perpetuem first; Gel/Solids as tolerated | Fluid and Endurolytes/Extreme as needed | Recoverite |
Sprint triathlon fuelling
Keep a Sprint plan simple: a tested HEED bottle or Hammer Gel is usually enough if extra fuel is needed. Use Endurolytes for conditions and finish with Recoverite after demanding racing.
Olympic triathlon nutrition
Start fuelling on the bike with HEED and/or Hammer Gel; carry the first run gel in T2. Keep Endurolytes and Recoverite part of the plan you have tested.
70.3 triathlon nutrition plan
Make Perpetuem the primary bike fuel from the outset, then use Hammer Gel and water on the run. Choose Endurolytes or Endurolytes Extreme for your tested conditions, then start recovery with Recoverite.
Ironman fuelling plan
For Iron-distance racing, begin Perpetuem early on the bike and stay consistent. Add Hammer Gel or Perpetuem Solids only as tolerated, use Endurolytes or Endurolytes Extreme according to conditions, and have Recoverite ready after the finish.
Triathlon Nutrition FAQs
How many calories per hour for a 70.3?
A practical Hammer starting range is 120–180 calories per hour, adjusted in training for body size, intensity, conditions and tolerance. Keep the bike plan consistent rather than trying to replace every calorie burned.
What should I drink during an Iron-distance triathlon?
Use a practised Perpetuem bottle as the main calorie source on the bike, take plain water as needed, and use Endurolytes or Endurolytes Extreme for your individual sweat losses and conditions.
Should I use Perpetuem or gels?
For most racing under about three hours, HEED and/or Hammer Gel are straightforward options. For 70.3 and Iron-distance racing, use Perpetuem as the primary bike fuel, with gels for convenient later-race or run fuel.
How much fluid per hour in a triathlon?
Many athletes start with a practised range of around 400–750 ml per hour, then adjust for heat, humidity, body size and sweat rate. Drink to your plan and conditions—avoid forcing fluid.
Triathlon is the ultimate test of multi-sport endurance — and the most complex fuelling challenge in sport. You need nutrition that works across three disciplines, survives transitions, and holds up over distances ranging from a 1-hour sprint to a 17-hour Ironman. This hub covers everything you need to fuel smarter across every triathlon distance.
Before Training & Racing – Pre-Session Nutrition
Consistent pre-session fuelling builds the glycogen reserves and electrolyte baseline that carry you through long training blocks and race day. Keep it light, fast-absorbing, and gut-friendly.
Recommended Products
- Hammer Gel – One sachet 15–30 minutes before swim, bike, or run sessions. Fast carbohydrate energy without the sugar spike — won’t cause GI issues in the water or on the run.
- HEED – Sip a bottle in the hour before long sessions or race morning to pre-load carbohydrates and electrolytes. No citric acid means no stomach issues.
- Endurolytes – 1–2 capsules before hot weather sessions or long bricks to prime electrolyte levels before sweat losses begin.
During Racing – Multi-Sport Fuel Strategy
The Swim
You can’t fuel during the swim — so your pre-race nutrition is critical. Hammer Gel 15–30 minutes before the start is the standard approach. For longer swims (1.9km+), ensure you’re fully topped up before entering the water.
The Bike – Your Primary Fuelling Window
The bike leg is where you do the majority of your fuelling. It’s the easiest discipline to eat and drink in, and the calories you take on here directly power your run.
- Hammer Gel – One sachet every 45–60 minutes for Sprint and Olympic distance. Easy to carry in a jersey pocket or taped to the top tube.
- Perpetuem – The go-to fuel for 70.3 and Ironman bike legs. Mix into a large bottle and sip consistently. Carbohydrates, protein, and fat in one formula — no need to carry multiple products for long-course racing.
- HEED – Combined energy and electrolyte drink for shorter bike legs. Ideal for Sprint and Olympic distance where simplicity matters.
- Endurolytes – 1–2 capsules per hour throughout the bike. Non-negotiable for 70.3 and Ironman in warm conditions.
- Endurolytes Extreme – For hot-weather racing or athletes who sweat heavily. Higher sodium concentration to match elevated losses on long bike legs.
- Anti Fatigue Caps - For long-course triathlon, provide additional nutritional support during prolonged exercise and can be used alongside your normal race-day fuelling strategy.
The Run – Gut-Friendly Fuel to the Finish
Running after cycling puts maximum stress on your GI system. Keep fuel simple, familiar, and proven in training.
- Hammer Gel – One sachet every 45–60 minutes on the run. Stick to flavours you’ve trained with — never try anything new on race day.
- Perpetuem Solids – Chewable fuel for the Ironman run when liquid fatigue sets in. Easy to carry in a race belt or pocket.
- Endurolytes – Continue every hour on the run. Cramping on the run is almost always an electrolyte issue, not a fitness issue.
- Explore individual gels, the 12-flavour sampler and the bulk jug in our Energy Gels collection when planning your triathlon nutrition.
After Training & Racing – Recovery Nutrition
Triathlon training is high volume and multi-discipline — recovery nutrition isn’t optional. The 30–45 minute post-session window is critical for glycogen replenishment and muscle repair between sessions.
- Recoverite – Hammer Nutrition’s dedicated endurance recovery drink. A 3:1 carbohydrate-to-protein ratio with glutamine and electrolytes — everything your body needs post-session in one shake. Essential after long bricks, race-pace sessions, and race day itself.
Triathlon Race-Distance Fuelling Plans
The right triathlon nutrition strategy depends on race duration. Use this as a starting plan, then fine-tune it in training for your body size, sweat rate, conditions and gut tolerance. For longer racing, a practical Hammer starting range is 120–180 calories per hour: fuel, fluid and electrolytes can be adjusted independently.
Sprint Triathlon
Typical duration: about 1–1.5 hours. Stored glycogen should cover most of the race, so keep the plan simple.
- Pre-race: normal carbohydrate-based meal 3–4 hours before; take 1 Hammer Gel 15–30 minutes before the swim if it has been tested in training.
- In-race calories: usually not necessary. For a longer or hotter Sprint, take 1 Hammer Gel on the bike or use a bottle of HEED.
- Fluid: drink to thirst; carry or collect water for the bike if conditions are warm.
- Electrolytes: use your practised Endurolytes dose in hot conditions or for high sweat losses.
- Recovery: rehydrate, then use Recoverite or a carbohydrate-and-protein meal within 30–45 minutes.
Olympic-Distance Triathlon
Typical duration: about 2–3.5 hours. Start fuelling on the bike rather than waiting for the run.
- Calories: begin with 120–180 calories per hour, using Hammer Gel and/or HEED; take a gel about every 45–60 minutes if gels are your main fuel.
- Fluid: use a practised range of about 400–750 ml per hour, adjusted for temperature and sweat rate.
- Electrolytes: use your established Endurolytes dose; increase only for heat or unusually salty sweat.
- Transitions: have the first bike fuel ready on the bike and move any run gel into T2 so the plan stays easy to execute.
- Recovery: begin fluids and Recoverite or a carbohydrate-and-protein meal soon after finishing.
70.3 (Half Iron Distance)
Typical duration: about 4.5–8 hours. The bike is the primary fuelling window; make the plan repeatable rather than reactive.
- Bike calories: start with 120–180 calories per hour. Make Perpetuem the primary bike fuel from the outset; use Hammer Gel or HEED where preferred and practised.
- Run calories: continue 120–180 calories per hour, typically with Hammer Gel and water; choose flavours and textures you have tested after cycling.
- Fluid: about 400–750 ml per hour, adjusted to conditions and your sweat rate.
- Electrolytes: take your established Endurolytes dose each hour and adjust for heat, humidity and individual sweat losses.
- Caffeine: if you use it, reserve a practised caffeine-containing gel or product for the later bike or final part of the run—not as a new race-day experiment.
- Transition: keep the first run gel and electrolyte dose accessible in T2; do not leave the bike behind on calories or fluid.
Iron-Distance Triathlon
Typical duration: about 9–17 hours. Use a paced, segmented plan and make adjustments before small problems become large ones.
- First 2 hours: settle the effort, begin sipping Perpetuem early, and establish your 120–180 calories-per-hour, fluid and electrolyte routine.
- Hours 2–5: stay consistent with Perpetuem as the primary bike fuel; drink roughly 400–750 ml per hour and take your practised Endurolytes dose each hour.
- 5+ hours: keep calories steady but use the fuel forms you can still tolerate—Perpetuem, Hammer Gel or Perpetuem Solids. Reassess fluids and electrolytes for heat, cold, changing pace and sweat losses.
- Transition to the run: take the first run fuel and electrolyte dose with you; simplify to Hammer Gel and water, with Perpetuem Solids only if you have trained with them.
- Recovery: start rehydrating immediately after the finish and use Recoverite or a carbohydrate-and-protein meal within 30–45 minutes.
Practise every part of your race plan in training. These are starting quantities, not a substitute for individual medical or sports-nutrition advice.
Triathlon Nutrition Products
- Hammer Gel – Fast-Acting Energy Gel
- HEED – Endurance Sports Drink
- Perpetuem – Long-Course Triathlon Fuel
- Perpetuem Solids – Chewable Run Fuel
- Endurolytes – Electrolyte Capsules
- Endurolytes Extreme – High-Strength Electrolytes
- Endurolytes Fizz – Effervescent Electrolyte Tablets
- Recoverite – Recovery Drink
Frequently Asked Questions – Triathlon Nutrition
What should I eat on race morning before a triathlon?
Eat a carbohydrate-rich meal 3–4 hours before your wave start — oats, rice, or toast with a small amount of protein. In the final 15–30 minutes before entering the water, take one Hammer Gel for a fast carbohydrate top-up. Avoid high-fat, high-fibre, or unfamiliar foods on race morning.
How do I fuel during an Iron distance triathlon?
Use Perpetuem as your primary bike fuel — sip every 15–20 minutes rather than waiting until hungry. Take Endurolytes every hour throughout. On the run, switch to Hammer Gel and Perpetuem Solids. Consume Recoverite immediately after crossing the finish line.
Can I use gels during the swim?
No — fuelling during the swim is not practical. This is why pre-race nutrition is critical. A Hammer Gel 15–30 minutes before the start ensures your glycogen stores are topped up before you enter the water. For longer swims (1.9km+), make sure your race morning meal was adequate.
What is the best fuel for a 70.3 triathlon?
For the bike leg, start with Hammer Gel and transition to Perpetuem for the second half. Keep Endurolytes consistent throughout. On the run, Hammer Gel every 45–60 minutes with Endurolytes each hour. Simplicity and consistency beat complexity every time.
How do I avoid GI issues on the triathlon run?
Only use nutrition you’ve trained with — never try new products on race day. Keep calorie intake conservative (120–180 calories per hour on the run). Hammer Gel’s maltodextrin base is gentler on the stomach than fructose-heavy gels. Stay hydrated with water alongside gels rather than mixing with sports drinks.
Do I need different electrolytes for hot-weather triathlon?
Yes — in heat or high humidity, standard electrolyte doses may not be sufficient. Upgrade to Endurolytes Extreme for higher sodium and electrolyte concentration. For bottle-based hydration on the bike, Endurolytes Fizz is a convenient effervescent option.
Winter is where much of the next season's fitness is built. Our Winter Nutrition & Immune Support Guide for Triathletes covers fuelling, hydration, recovery and important micronutrient considerations for consistent winter training