The week before a triathlon is where most athletes either lock in a strong race or quietly sabotage one. Training is done. Fitness is set. The only variable still in play is nutrition — and most triathletes either under-do it (training habits, no taper adjustment) or over-do it (anxiety eating, pasta dinner the night before and nothing else). Neither works.

This is the day-by-day nutrition plan for the 7 days before a 70.3 or 140.6. Most principles apply to marathons too, but triathlon has specific considerations — the multi-leg structure, the longer carb load requirement, and the need to think about both solid and liquid nutrition — that make a dedicated guide worth having.

The goal of race week nutrition

Everything in race week serves one of three purposes: fill glycogen, stay healthy, and show up at the start line without anything new in the gut. You are not trying to get fitter. You are not trying to lose weight. You are loading the tank and protecting it.

Muscle glycogen stores typically sit at 400–500 grams at baseline. With a structured carb load, you can push that to 700–900 grams — a 40–80% increase that directly delays the bonk. For a 140.6 lasting 9–17 hours, that glycogen buffer is the difference between a strong marathon and a walk from mile 16.

D-7 to D-5: taper week, normal eating

Most athletes begin tapering training volume in the 7–10 days before race day. This is also when nutrition should start shifting, but not as dramatically as many think.

Days 7–5 out: Eat your normal training diet. Keep carbohydrates at or slightly above training levels — 5–7 g/kg/day. Reduce fiber slightly beginning on day 5 (cut raw vegetables, legumes, and whole grains in favor of their lower-fiber equivalents). This is not the carb load; it is preparation for the load.

Avoid the trap of eating less because you are training less. Your body is using the taper period to repair tissue and top off glycogen even without long training sessions. Under-eating in the taper is the most common race-week mistake that does not feel like a mistake until mile 80 of the bike.

D-4 to D-3: start the load

Three to four days out is when carb loading begins in earnest. This is supported by a large body of research: Burke (2010) and Bussau (2002) both demonstrate that 36–48 hours of elevated carbohydrate intake is sufficient to saturate muscle glycogen, especially when combined with a reduction in training load.

Day 4: Push carbohydrate intake to 7–8 g/kg. For a 70 kg athlete, that is 490–560 g of carbohydrate across the day. White rice, pasta with simple sauce, white bread, bananas, sports drinks, and fruit juice are your primary tools. Fat and fiber should be minimal.

Day 3: Same targets. Training should be at most a short shakeout swim or run — nothing that depletes the glycogen you are trying to store. Some athletes feel heavy and full during this phase. That is correct. Glycogen binds water at roughly 3:1, so each additional 100 g of glycogen adds about 300 g of water weight. This is not something to manage away — it is the point.

Sleep quality and stress management matter here more than most athletes realize. Cortisol from poor sleep or travel anxiety impairs glycogen synthesis. If you are flying to the race, eat your carb-load meals before the flight, not after. Airport food is terrible for loading.

D-2: peak carb day

Two days out is the highest-carbohydrate day of the week. This is where most athletes under-deliver because the quantities feel excessive.

Target: 10–12 g/kg carbohydrate. For a 75 kg athlete, that is 750–900 grams. Spread across four to five meals and include liquid sources to make volume manageable: a sports drink with each meal, fruit juice as a snack, a recovery drink in the afternoon.

A sample D-2 template at 800 g carb:

  • Breakfast: 2 cups oatmeal + sliced banana + honey + sports drink (250 g carb)
  • Lunch: Large white rice bowl with teriyaki chicken + half a banana + 500 mL sports drink (220 g carb)
  • Afternoon snack: White bread + jam + fruit juice (100 g carb)
  • Dinner: Pasta with tomato sauce + plain bread + water (230 g carb)

No raw salads. No beans. No cruciferous vegetables. No heavy cream sauces. No alcohol.

D-1: race eve — familiar and early

Race eve is not the night to push harder on loading. You have done the work on days 3 and 2. Race eve is about maintaining glycogen levels with familiar, easy-to-digest food and protecting your gut for the next morning.

Carbohydrate target: 8–10 g/kg — a step down from D-2. Eat your main meal by 6 PM at the latest for a morning race. That leaves 10–12 hours of gut clearance time before T-zone and the swim start.

The safest dinner template: 200 g dry pasta (weighed) with marinara or plain tomato sauce, grilled chicken breast, a side of plain white bread. No garlic. No salad. No wine.

The classic mistake is eating a massive pasta bowl at 9 PM because you cannot sleep and feel like you need more carbs. You do not. The food will not have cleared by race morning, your gut will be working at the gun, and the risk of GI distress on the run doubles.

Hydrate carefully in the evening: 500–800 mL of water plus an electrolyte drink. Arrive at the swim start with pale yellow urine — not clear (over-hydrated) and not dark (under-hydrated).

Race morning: the T-minus protocol

Liver glycogen depletes by 30–50% overnight just fueling your brain and basal metabolism. Race morning breakfast tops the liver back up and sets blood glucose on a rising trajectory before the gun.

T-minus 3–4 hours: Main breakfast. Target 1–2 g carbohydrate per kg bodyweight. White rice with banana, bagel with jam and peanut butter (thin layer), or oatmeal with honey. Low fat, low fiber, familiar.

T-minus 60–90 minutes: Optional top-up of 30–50 g if your gut tolerates it — a banana, half a bagel, or a sports drink.

T-minus 15 minutes: One gel plus water. This is the zero-mile gel. It peaks in your bloodstream around T1. Do not skip it.

For a 140.6 athlete starting at 7 AM: wake at 3:30 AM, eat by 4 AM, top-up snack at 5:30 AM, gel at 6:45 AM. If this sounds brutal, it is — but it is significantly less brutal than bonking on the marathon at hour 12.

Coffee: yes or no

If you drink coffee daily, drink it on race morning. Caffeine at 3–6 mg/kg taken 60 minutes before the gun is one of the most consistently proven ergogenic interventions in endurance sport. For a 70 kg athlete, that is one strong drip coffee or a caffeinated gel. Time it so the peak lands early on the bike, not in T1 transition while you are still dealing with wetsuit removal.

If you do not drink coffee regularly, race morning is not the time to start. The GI side effects — urgency, cramping — arrive without the performance benefit that habituated users get. Full protocol in our caffeine strategy guide.

What to avoid all week

  • Anything new. New restaurants, new foods, new supplements, new gel brands. Race week is not the time to experiment.
  • Alcohol. Impairs sleep quality, slows glycogen synthesis, and dehydrates. Even one beer on D-2 has a measurable effect.
  • High-fiber foods from D-3 onward. Beans, lentils, cruciferous vegetables, whole-grain bread, raw salads. These slow gastric transit and raise the risk of GI distress on race day.
  • Aggressive fat restriction from D-1. Fat is not the enemy in race week — fiber is. Some fat at meals slows gastric emptying slightly, which is fine. Cutting fat to zero in an attempt to eat more carbs is unnecessary and makes eating unpleasant.
  • Over-eating on race eve. The glycogen is already stored from D-3 and D-2. A massive dinner on race eve is just undigested food at the gun.
  • Under-hydrating. A common response to pre-race anxiety is forgetting to drink. Keep a bottle in hand through the afternoon and evening of D-1.

Triathlon-specific considerations vs. pure running

Triathlon carb loading needs to run longer than marathon carb loading because the event is longer. For a 70.3 lasting 4–7 hours, two days of loading is sufficient. For a 140.6 lasting 8–17 hours, three full days of loading is the minimum.

Triathlon athletes also need to think about liquid nutrition tolerability more carefully than runners do. Everything you will put down on the bike — bottles, gels, chews — should be practiced extensively. If you are arriving at a 140.6 having practiced 80 g/hr on only two or three long rides, you are under-prepared for a 5–7 hour bike leg.

The T1 and T2 transition fueling playbook covers what specifically to do in the minutes between legs — including the single-gel strategy in T1 that most triathletes skip.

The plan behind the plan

Race week nutrition sets up your glycogen stores. But what you do with those stores over 8–17 hours depends on having a minute-by-minute fueling plan built for your specific weight, sweat rate, race-day temperature, and target time.

Arriving at the start line fully loaded with no plan for what to eat and when is like bringing a full tank of gas and no map. The athletes who finish strong are the ones who decided at mile 0 of the bike what they would eat at mile 20, mile 40, and mile 60 — before fatigue clouded their judgment.

Frequently asked questions

Do I need to carb load for a 70.3? Yes, but the protocol is shorter. Two days of elevated carbohydrate (7–9 g/kg/day) is sufficient for a 4–7 hour event. Three days is better if your race falls on the longer end.

What if race week includes travel? Pack your own food. Airport food is high fat, high fiber, and low in fast-acting carbs. A bag of white rice cakes, bananas, white bread, and sports drink powder gives you full control and costs almost nothing. Eat your largest carb-load meal before you board.

I gained 2 kg this week — is that normal? Yes. Glycogen binds water at 3:1. Each additional 100 g of stored glycogen adds roughly 300 g of water weight. A proper 3-day load adds 1–3 kg. It disappears in the first 90 minutes of the race and works for you the whole time.

Can I keep training through race week? Short sessions at easy effort only. The goal is to not deplete glycogen faster than you can load it. A 30-minute easy swim on D-3 is fine. A 3-hour ride is not.

How do I know if my race-day plan is actually right for me? Generic race week guides — including this one — give you the framework. A plan that calculates your specific carb targets, fluid needs, and per-segment fueling from your own inputs gives you the execution blueprint. The difference shows up in the marathon.