Your Last Long Run Is Done — Here's How to Lock In Your Race-Day Fueling Plan

You have done the work. Twenty-milers, back-to-back long weekends, sunrise runs in August heat. Your legs are ready. But the question that creeps in during taper week is not about fitness — it is about fueling.

Is your nutrition plan actually right? Should you change gels? Take more sodium? Start fueling earlier? Every forum post, podcast episode, and expo freebie is suddenly whispering a different answer.

Here is the truth: the best data you will ever have about your race-day nutrition is already sitting in your training log. The job now is not to reinvent your plan. It is to review what worked, fix what did not, and lock everything in so that on race morning, there are zero nutrition decisions left to make.

Step 1: Audit Your Long-Run Fueling Data

Pull up your last four to six long runs — the ones where you practised race-day nutrition. For each one, write down five things.

What you consumed. Every gel, every sip of drink mix, every handful of sweets. Include the brand, the flavour, and the carbohydrate content per serving. If you do not know the carb content, look it up now. You need actual numbers, not vibes.

When you took it. Note the time or distance interval. Were you taking a gel every 30 minutes? Every 5 kilometres? At aid stations? The pattern matters because race day will impose its own rhythm — aid station spacing, crowd noise, adrenaline — and you need to know whether your fueling was time-based or distance-based so you can stick to it.

How you felt. This is the gut check — literally. Did you feel good at the end? Was there nausea, bloating, or any GI distress after a particular product or timing? Did you fade in the final third? Could you eat and drink comfortably, or were you forcing it down?

What the conditions were. Temperature, humidity, time of day. A plan that worked at 6am in 18°C will behave differently at 10am in 25°C. If your race-day forecast is significantly different from your training conditions, you will need to adjust.

What your watch says. Heart rate drift in the second half, average pace, and — if your watch estimates it — sweat loss. These numbers tell you whether your hydration held up or whether dehydration crept in despite feeling "fine."

If you did not practise race nutrition during training, your audit will be short and your risk on race day will be higher. That is honest, not fatal. Use the next section to build a conservative plan from scratch, test it on one more moderate-length run before taper, and keep it simple.

Step 2: Identify What Worked and What Did Not

With your audit in front of you, look for patterns.

The sessions that felt good are your baseline. Whatever you consumed on those days — the specific products, the timing, the quantities — is your starting template. Do not change these things. The urge to optimise during taper is strong. Resist it.

The sessions where something went wrong are your data. A single bad run is noise. Two or three runs with the same issue — nausea from a specific gel, fading energy after kilometre 28, cramping despite electrolytes — is a signal.

Common patterns and what they mean:

Energy faded in the final 8–10 kilometres despite eating. You probably started fueling too late. Most runners wait until they feel hungry, which is 20–30 minutes after their glycogen stores have already dipped. Move your first intake earlier — within the first 20–30 minutes of the run — and keep the intervals consistent.

GI distress appeared after a particular product. Drop that product. This is not the time to gut-train around it. Replace it with something you have tolerated well on other runs and test the swap once on a moderate run before taper.

You felt great on training runs but your heart rate drifted up 10+ beats in the second half. This is a hydration signal, even if you did not feel thirsty. Increase your fluid intake by 100–200ml per hour and add electrolytes if you were drinking plain water.

You cramped despite taking electrolytes. Cramping at race-effort intensity is often neuromuscular fatigue, not electrolyte deficiency. But if you were only taking 200–300mg of sodium per hour, try increasing to 400–500mg. More than that rarely helps and can cause stomach issues.

Step 3: Build Your Locked Plan

A locked plan has four components. Each one should be specific enough that someone else could execute it for you.

Products. List every item you will carry or pick up on course. Include the exact brand and flavour — not "gels," but "SiS GO Isotonic Gel, Orange, 22g carbs per sachet." Check the race's on-course nutrition and decide now whether you will use it or carry your own. If you are carrying your own, count exactly how many you need and add one extra.

Timing. Write down when you will take each item. "Gel at 30 minutes, then every 25 minutes" is better than "every few kilometres." Tie it to your watch timer, not aid station locations — stations are crowded, you might miss one, and your rhythm should not depend on race logistics.

Quantities. Calculate your total carbohydrate and fluid targets per hour. A reasonable starting point for most marathon runners is 60–80g of carbs per hour and 400–800ml of fluid per hour, adjusted for your body weight, pace, and conditions. If your long runs went well at 60g per hour, do not jump to 90g on race day because a podcast said you should.

Contingency. Plan B is not optional. Know what you will do if you miss a gel window, if an aid station is out of your drink, or if your stomach rebels at kilometre 25. The plan should be: slow down, take smaller sips, switch to a simpler carb source (flat cola, sweets), and never panic-eat three gels at once to "catch up."

Step 4: Adjust for Race-Day Conditions

Your training plan was built for training pace and training conditions. Race day changes both.

Intensity. You will run faster than training pace. Higher intensity reduces blood flow to your gut, which means your stomach tolerates less food per hour at race pace than at easy long-run pace. If you trained at 5:30/km and you plan to race at 5:00/km, your gut capacity drops. This is why athletes who fueled comfortably at 80g per hour in training suddenly feel sick at 80g per hour on race day. Consider reducing by 10–15% or shifting more of your carbs to liquid form, which absorbs faster than gels.

Temperature. If race day is warmer than your training, increase fluids and sodium. If it is cooler — which is common for fall marathons after summer training — you may be able to reduce fluid slightly, but do not reduce carbs. A cooler race means lower sweat losses but not lower energy demands. Your muscles still need the same fuel.

Adrenaline. Race-day nerves speed up your metabolism and can cause GI distress on their own. This is why a calm race-morning routine matters. Eat your pre-race meal at the same time you practised it in training. Do not add extra food "for energy" because you are anxious.

Step 5: Write It Down and Stop Thinking About It

The purpose of locking in your plan is to remove every nutrition decision from race day. By the time you reach the start line, your only job is execution.

Write your plan on a card or save it in your phone. Include:

• Pre-race meal (what, when, how much)
• First fuel intake (what, when)
• Ongoing fuel schedule (product, interval, quantity per hour)
• Fluid schedule (what, how much per hour)
• Contingency protocol (what to do if something goes wrong)

Then stop reading articles about race nutrition. Stop asking in forums. Stop second-guessing because a faster friend uses a different gel. Your plan is built from your data, your gut, and your training — not from someone else's.

The Gap Between "Practise in Training" and "Know Your Plan Is Right"

Every race nutrition guide tells you to practise in training. Few tell you what to do with the data from those practice runs. The result is athletes who practised dutifully for four months but still do not know whether their plan is actually optimised for race day — because they never audited the data their training produced.

Your Apple Watch or Garmin recorded heart rate, pace, temperature, and estimated sweat loss for every long run you did this summer. Your gut told you which products worked and which did not. Your energy levels in the final third told you whether your carb timing was right.

Sweatr pulls all of that together. It takes your wearable data, your training history, your race-day conditions, and your body weight, and builds a specific, timed fueling plan — the exact gels, the exact fluids, the exact intervals — that you can follow from the start line to the finish. No guesswork. No taper-week panic. Just a plan built from your actual data.

Your training is done. Your plan should be too.