Carbohydrate Timing: When to Eat Carbs Around Your Workouts
Most endurance athletes have figured out roughly what to eat. Far fewer have figured out when. Yet the timing of your carbohydrate intake — before, during and after training — arguably has a bigger effect on how a session feels, and how well you recover from it, than the brand of fuel in your jersey pocket. Eat the right amount at the wrong time and you can still find yourself flat at hour two, or dragging your legs through tomorrow's session because glycogen never got properly restocked.
The good news is that carbohydrate timing around workouts isn't complicated once you understand the logic behind it. Your body has a limited glycogen store — roughly 400–500g in muscle and liver combined for a trained athlete, worth around 1,600–2,000 kcal — and everything about timing comes down to managing that store: topping it up before you start, defending it while you train, and refilling it quickly afterwards. Here's how to do each one properly.
Why Carbohydrate Timing Around Workouts Matters
Carbohydrate is your body's preferred fuel for anything above a gentle jog or an easy spin. At moderate to high intensities — the zones where most quality training happens — carbohydrate can supply the majority of your energy, and the harder you go, the more your muscles lean on it. The problem is storage. Unlike fat, which even the leanest athlete carries tens of thousands of calories of, glycogen runs out in roughly 90 minutes to 2 hours of solid effort.
That's why timing matters more for carbs than for any other nutrient. Protein and fat can be spread through the day without much consequence. Carbohydrate, on the other hand, does very different jobs depending on when it arrives. Eaten 2–3 hours before a session, it tops up liver glycogen and stabilises blood glucose. Eaten during a long session, it spares your stored glycogen and keeps your brain supplied. Eaten in the hour after training, it takes advantage of a window when your muscles restock glycogen at roughly 150% of the normal rate. Same nutrient, three completely different roles.
Before Training: Topping Up the Tank
The main pre-session meal should land 2–3 hours before you start, and for a hard or long session it wants to contain around 1–2g of carbohydrate per kilogram of body weight. For a 70kg athlete, that's 70–140g — a decent bowl of porridge with banana and honey, or rice with eggs, sits comfortably in that range. Going low-fibre and low-fat here helps the meal clear your stomach before you start working.
If you train early in the morning, you won't manage a full meal — and you don't need to. Liver glycogen drops overnight (your brain burns through it while you sleep), so even 30–50g of quick carbohydrate 30–60 minutes before an early session makes a measurable difference: a banana, a slice of toast with jam, or a few energy pastilles with your coffee. For easy sessions under an hour, training fasted is perfectly fine and some athletes deliberately do so; just don't make a habit of taking on your hardest intervals empty.
One caveat worth knowing: some people experience rebound hypoglycaemia if they eat a large hit of fast sugar 30–45 minutes before starting — blood glucose spikes, insulin responds, and they begin the session feeling wobbly. If that's you, either eat closer to the start (within 10–15 minutes, when exercise itself blunts the insulin response) or push your carbs back to the 2–3 hour window.
During Training: When Mid-Session Carbs Are Worth It
The threshold that matters here is duration. For sessions under 60–75 minutes, you don't need to fuel mid-session — your stored glycogen covers it. Beyond that, the numbers scale with time: aim for 30–60g of carbohydrate per hour for sessions of 1–2.5 hours, and 60–90g per hour for anything longer or race-pace efforts, using a mix of glucose and fructose so your gut can actually absorb the higher amounts.
Timing within the session matters too. The most common mistake is starting too late — waiting until you feel hungry or flat, by which point you're already running down your reserves. Glycogen you've burned can't be replaced mid-ride; you can only slow the drain. Start fuelling 20–30 minutes in, then keep taking small amounts every 20–30 minutes rather than one big feed every hour and a half. Little and often keeps blood glucose stable and is far kinder to your stomach.
After Training: The Refuelling Window
The famous "30-minute window" is real, but it's often misunderstood. Muscle glycogen synthesis is elevated for several hours after exercise, with the first 60 minutes being the most rapid phase. If you have 24 hours or more before your next hard session, total daily carbohydrate intake matters far more than precise timing — you'll restock fully either way.
Where timing becomes genuinely important is when recovery time is short: doubling up sessions, back-to-back big training days, or stage events. In those situations, aim for 1–1.2g of carbohydrate per kilogram of body weight per hour for the first 3–4 hours after finishing — roughly 70–85g per hour for a 70kg athlete. Adding 20–25g of protein to the first feed supports muscle repair and may modestly improve glycogen storage when carbohydrate intake is on the lower side.
Practically, that means eating something within the first half hour even if you're not hungry — hard sessions suppress appetite, which is exactly when athletes under-fuel their recovery. A recovery shake, flavoured milk, or a handful of pastilles and a sandwich all work; what matters is getting carbohydrate moving into the muscle while the enzymatic machinery is primed.
What We Use at FTP Endurance Fuel
The awkward gaps in carbohydrate timing around workouts — the pre-dawn start, the mid-ride top-up, the immediate post-session feed before a proper meal — are exactly where we lean on our own pastilles. Each one delivers a measured dose of quick carbohydrate with a 1:1 glucose-to-fructose ratio, so it's easy to hit a precise hourly target: count them out, pocket them, and take one every 15–20 minutes. Our Mixed Fruit Pastilles come in a 1kg bulk pack, which makes the per-session cost low enough to fuel every training day properly, not just race day. For athletes juggling training with early starts and quick turnarounds, having fuel that requires zero preparation removes one more excuse for skipping the timing that matters.
Carbohydrate timing isn't about obsessive precision — it's about putting fuel where it does the most work: a proper meal 2–3 hours out, steady small doses during anything over an hour, and a prompt refeed when recovery time is tight. Get those three habits in place and most of your fuelling problems quietly disappear. If you want a simple way to nail the during and after portions, our bundles are the most cost-effective way to keep your training fuel stocked all season.
