What to eat the week before a triathlon

Race week nutrition is not the time for experimentation. It is the time to execute a strategy you have practised in training. The athletes who get this wrong — and many do — spend race day managing GI distress instead of managing pace. Everything you eat in the final seven days should serve one purpose: arrive at the start line with full glycogen stores, a hydrated body, and a gut that has no surprises in store.

Seven days out: steady, familiar, carb-conscious

The week before your race is not a carb loading free-for-all. For the first four to five days, eat normally with a slight increase in carbohydrate proportion. Focus on familiar foods. Remove anything high in fibre, spice, or fat that might irritate your gut. Your training volume is tapering, so total calorie intake should drop slightly even as carbohydrate percentage rises.

Daily protein stays at 1.6–2.0 g/kg bodyweight for muscle maintenance and repair. This is particularly important during taper when training stimulus drops but the body is still consolidating adaptations from the build phase.

Two days out: the carbohydrate load begins

The final 48 hours before race day is when deliberate carbohydrate loading matters. Target 8–10 g of carbohydrate per kilogram of bodyweight across the day. For a 70 kg athlete, that is 560–700 g of carbohydrate — roughly 2,200–2,800 calories from carbs alone. This is more than most people expect.

Stick to simple, low-fibre carbohydrate sources: white rice, white pasta, white bread, pancakes, fruit juice, sports drink, honey. Reduce vegetables, legumes and whole grains temporarily — they fill you up before you hit your carbohydrate target and can cause bloating.

Race morning: the final fuel

Eat 3–4 hours before your start time. Target 1–2 g/kg bodyweight of carbohydrate. The meal should be low in fat and low in fibre. Familiar foods only. Toast with honey, a banana, a bowl of white rice with a small amount of protein — whatever you have tested in training.

In the final 30–60 minutes before the swim start, consider 20–30 g of fast-release carbohydrate — a gel or half a banana. For sprint-distance races under 90 minutes, skip this. For Olympic distance and beyond, it tops up liver glycogen without risking GI upset.

Race day fuelling by distance

Your on-course nutrition strategy should have been rehearsed at least two to three times in long training sessions. Glycogen depletion is extremely difficult to reverse once it begins — fuel proactively from the first 20 minutes of the bike, not reactively when you feel empty.

Hydration and sodium: the forgotten variables

Fluid targets vary by conditions: 500–600 mL/hr in cool weather, 750–1,000 mL/hr in heat. But these are starting points. Your individual sweat rate can be measured with a simple pre-and-post-session weigh-in — 1 kg lost equals roughly 1 litre of sweat.

Sodium is critical for sessions and races beyond 90 minutes. Average sweat sodium concentration ranges from 500–1,500 mg/L, which varies enormously between athletes. Target 300–700 mg of sodium per hour through electrolyte tabs, sports drink or salt capsules. Low sodium intake during long races is a leading cause of cramping, nausea and heat illness.

Train your gut like you train your legs

The gut can absorb approximately 60 g/hr of glucose through one intestinal transporter, and a further 30 g/hr of fructose through a separate one. Products using a 2:1 glucose-to-fructose ratio allow 80–90 g/hr absorption without GI distress — but only if you have trained for it.

A structured gut training protocol over 7+ weeks progressively increases carbohydrate intake from 40 g/hr up to 80–90 g/hr, using the specific products you plan to race with. Do this on the bike, where most race-day fuelling occurs and where GI issues most commonly arise.

The biggest nutrition mistake in endurance racing is not what you eat — it is eating something for the first time on race day. Every gel, every drink, every bar should have been tested under load before you pin on a race number.