How to Build an Endurance Nutrition Plan From Scratch
Most endurance athletes don't have a nutrition plan. They have a bag of gels bought in a panic the week before a race, a vague memory of "60 grams an hour" from a podcast, and a habit of eating whatever is at the feed station. Then they wonder why the last 90 minutes of every long event feels like wading through treacle.
Building an endurance nutrition plan from scratch is not complicated, but it does need to be done deliberately and then tested. This guide walks through the five decisions that matter, with real numbers you can plug into your own training. It works whether you're targeting a first half marathon, a 100-mile sportive or a full-distance triathlon. The principles are the same; only the totals change.
Step 1: Work Out What Your Event Actually Demands
The starting point for any endurance nutrition plan is duration and intensity, not distance. A 100km ride at 25km/h is four hours of moderate work; the same ride in a fast group at 32km/h is barely three hours but at a far higher glycogen burn rate. Your body stores roughly 400–500g of glycogen across muscle and liver, which is somewhere between 1,600 and 2,000 kcal. At a decent tempo effort you'll burn through that in around 90 minutes to two hours. Everything after that has to come from what you eat on the move or from fat oxidation, which cannot keep pace with hard efforts.
So the first rule is simple: if the event is under 75 minutes, you don't need to fuel during it. Eat well beforehand and go. If it's between 75 minutes and two and a half hours, you need a modest intake. If it's over two and a half hours, fuelling becomes the single biggest controllable variable in how the second half goes.
- Under 75 minutes: no in-session carbohydrate needed
- 75 minutes to 2.5 hours: 30–60g of carbohydrate per hour
- 2.5 hours and beyond: 60–90g per hour, with the upper end only if you've trained your gut for it
Step 2: Set Your Hourly Carbohydrate Target
The 60g figure that gets repeated everywhere comes from the maximum rate at which the gut can absorb glucose via the SGLT1 transporter. Push more glucose than that and it sits in the stomach, which is where the sloshing and nausea come from. To get above 60g you need a second sugar, fructose, which uses a different transporter (GLUT5). A blend of glucose and fructose in roughly a 1:0.8 to 1:1 ratio is what allows trained athletes to absorb 90g per hour and, in some lab studies, up to 120g.
For most amateur athletes building a plan for the first time, I'd set the target at 60g per hour for anything over two hours and work up from there. That translates to about 240 kcal of carbohydrate per hour. Don't try to jump straight to 90g on race day if you've been training on 30g; your stomach won't thank you.
A useful way to make this concrete is to write it down as products rather than grams. If a serving of pastilles delivers around 25g of carbohydrate, 60g per hour means two to three servings spread across the hour, ideally one every 20 minutes. Small, regular doses absorb better than one big hit every hour, and they keep blood glucose steadier.
Step 3: Sort Out Fluids and Sodium Separately
A common mistake in a first endurance nutrition plan is trying to get all your carbohydrate from drink. It works up to a point, but hitting 60–90g per hour from a bottle means either a very concentrated mix that upsets the stomach or drinking more than a litre an hour, which most people can't do. Splitting carbohydrate into solids and fluids gives you far more flexibility, especially when the weather changes.
Fluid needs vary hugely. Sweat rates range from around 0.5 litres per hour on a cool day to over 2 litres per hour in heat, so the only reliable way to know yours is to weigh yourself before and after a one-hour session with no toilet stops. Every kilogram lost is roughly a litre of sweat. Aim to replace 50–80% of that during the event, not 100%.
Sodium matters most for sessions over three hours or in warm conditions. Typical sweat sodium concentration is 500–1,500mg per litre, so at a litre an hour you might lose 1g of sodium hourly. A target of 300–600mg of sodium per hour covers most people. Keep this in a separate product from your carbohydrate so you can adjust one without changing the other.
Step 4: Plan the 48 Hours Before and the Hour After
What you do in the two days before an event is worth more than any last-minute breakfast. For events over 90 minutes, increase carbohydrate intake to 8–10g per kilogram of bodyweight per day for the final 36–48 hours. For a 70kg athlete that's 560–700g per day, which sounds enormous until you realise that a big bowl of pasta is only 70–80g. It means swapping some fat and fibre for rice, bread, potatoes and fruit juice, not eating more overall.
Race-day breakfast should be 1–4g of carbohydrate per kilogram, eaten two to three hours before the start. Keep it low in fibre and fat: porridge with honey, white toast and jam, or a bagel with banana all work. Then take 20–30g of carbohydrate in the final 15 minutes before the gun if the event is long.
Afterwards, the recovery window is real but less urgent than it used to be sold. Aim for around 1g of carbohydrate per kilogram plus 20–30g of protein within the first hour or two, then a proper meal. If you're training again within 24 hours, that first hour genuinely matters because glycogen resynthesis is fastest immediately post-exercise. If your next hard session is two days away, a normal meal within a couple of hours is fine.
Step 5: Test It, Then Write It Down
A plan that only exists in your head is not a plan. Once you've set your numbers, write out a simple timeline for the event: what you eat at breakfast, what goes in each pocket or bottle, and when you take each dose. Then practise the exact protocol on your two or three longest training sessions. The gut is trainable; studies show that a couple of weeks of regular in-session carbohydrate intake measurably improves absorption and reduces GI symptoms.
Keep a note after each long session of what you ate, how much, and how you felt in the final third. After three or four sessions you'll have a working endurance nutrition plan that's built on your own data rather than someone else's, and you'll know exactly what to adjust if race day turns out hotter, longer or harder than expected.
What We Use at FTP Endurance Fuel
The reason we make pastilles rather than gels is that they solve the two problems most people hit when building their first plan: getting enough carbohydrate in without stomach trouble, and being able to dose in small, regular amounts. Each pastille delivers a measured hit of glucose and fructose, so you can take one or two every 15–20 minutes rather than gulping a gel and hoping.
Our Mixed Fruit Pastilles are the straightforward option for in-session carbohydrate, and because they come in a 1kg bulk pack you can weigh out exactly what your plan needs for each session rather than paying per sachet. The Tart Cherry Pastilles do the same job with the added anthocyanins from Montmorency cherry, which is why a lot of our customers use them in the final hour of a long day and again after finishing. If you're still working out what suits you, the Taster Pack is the sensible place to start before committing to a bulk bag.
Building an endurance nutrition plan from scratch comes down to five decisions: how long you'll be out, how many grams of carbohydrate per hour, how much fluid and sodium, what you eat in the days around the event, and how you'll test it. Get those written down, practise them on your long sessions, and the last hour of your next big day will feel very different. When you're ready to stock up, have a look at our bundles to get the best value on the products your plan calls for.
