The Best Running Snacks for Long Training Runs
Once your training runs stretch past the 75-minute mark, what you eat mid-run stops being optional and starts being the difference between finishing strong and grinding home on empty. Your body stores roughly 400–500g of glycogen — enough for about 90 minutes of steady running — and after that, you're running on whatever you can absorb on the move. Get it right and the last 5km of a 30km run feels controlled. Get it wrong and you'll know all about it.
The trouble is that "running snacks" covers everything from jelly sweets to flapjacks to engineered gels, and most runners settle on whatever they grabbed at the petrol station before their first long run and never revisit the decision. This guide breaks down the best running snacks for long training runs — what actually digests well at threshold heart rate, how much to carry, and when to eat it.
What Makes a Good Mid-Run Snack
The criteria are stricter than most runners realise. When you're running, blood is diverted away from your gut towards your working muscles — by some estimates gut blood flow drops by up to 80% during hard efforts. That means anything you eat needs to be easy to digest, or it will simply sit in your stomach causing trouble.
A good long-run snack should tick four boxes:
- Carbohydrate-dense: you want 20–30g of carbs per portion without a lot of bulk. Fibre, fat and protein all slow gastric emptying, which is exactly what you don't want mid-run.
- Easy to eat on the move: if it requires two hands, chewing for a minute, or a mouthful of water to get down, it will stay in your pocket. Bouncing along at 5:30/km is not the moment for a dense oat bar.
- Gentle on the stomach: a sensible glucose-to-fructose balance matters. Your gut absorbs glucose and fructose through separate transporters, so a roughly 1:1 blend lets you take on more carbohydrate per hour without the sloshing, bloated feeling that pure-glucose products can cause.
- Something you actually want to eat: flavour fatigue is real. At hour two, an overly sweet, synthetic-tasting gel can become genuinely hard to swallow. Palatability is a performance factor, not a luxury.
The Best Running Snacks for Long Training Runs, Ranked by Job
Rather than one "best" snack, think in categories — each does a slightly different job.
Energy chews and pastilles are the most practical all-rounder for most runners. They deliver concentrated carbohydrate in small, controllable doses — typically 4–5g of carbs per pastille — so you can drip-feed energy every 10–15 minutes rather than dumping 25g into your stomach in one go. That steady trickle is far kinder on the gut than the gel "bolus" approach, and there's no sticky wrapper to wrestle with.
Gels are fast and precise, and they still have a place on race day when you want maximum carbs with minimum faff. Their downside for training runs is the texture — many runners find that beyond two or three gels, their stomach starts to protest, and the empty wrappers are messy in a pocket.
Dried fruit — dates, raisins, dried mango — is cheap and carb-rich. Two Medjool dates give you around 36g of carbs. The catch is fibre: fine for easy-paced runs, but at marathon pace or quicker, that fibre can trigger exactly the GI distress you're trying to avoid.
Flapjacks and bars work on very long, easy efforts — ultra training, run-walk days — where intensity is low and your gut can handle fat and fibre. At anything above conversational pace, save them for afterwards.
Jelly sweets from the corner shop are the budget classic, and they broadly work — they're mostly glucose syrup. But the carb content per sweet is inconsistent, the dose is hard to control, and there are no electrolytes. They're a decent emergency option rather than a plan.
How Much to Eat and When
The numbers matter more than the product. For runs of 60–90 minutes, you can get away with 30g of carbohydrate per hour, or even nothing if the pace is genuinely easy. For runs of 90 minutes to 2.5 hours, aim for 40–60g per hour. Beyond that — marathon and ultra training — well-trained guts can absorb up to 90g per hour using mixed glucose and fructose sources.
Timing is simple: start early and eat little and often. Take your first snack 20–30 minutes into the run, before you feel you need it — by the time you feel hungry or flat, you're already 30–45 minutes behind on absorption. Then keep a steady rhythm: a couple of pastilles every 15 minutes beats a whole packet every 45. Set a recurring alert on your watch if you're forgetful — most runners under-fuel not because they carried too little, but because they simply forgot to eat once the miles got hard.
Two more practical points. First, train your gut like you train your legs — practise your race-day fuelling on long runs weekly, because the gut adapts to processing carbs on the move. Second, pair food with fluid: around 500ml of water per hour helps carbohydrate absorption and keeps concentrated snacks from sitting heavily.
What to Avoid on Long Runs
A few things reliably cause problems. High-fibre bars and anything wholegrain slow digestion and can send you searching for a hedge. High-fat snacks — nuts, chocolate, peanut butter — sit in the stomach for hours. Untested caffeine products can work brilliantly or disastrously, so trial them on shorter runs first. And avoid trying anything new in the final weeks before a race: the long-run window is for rehearsing what works, not experimenting.
What We Use at FTP Endurance Fuel
We built our range around exactly the problems described above. Our Mixed Fruit Energy Pastilles use a 1:1 glucose-to-fructose blend so you can push towards that 60–90g per hour range without gut trouble, and the individual pastille format means you control the dose — a few every 15 minutes, straight from a jersey or shorts pocket. Each one is small enough to eat mid-stride without breaking rhythm.
For runners logging serious weekly mileage, the 1kg bulk packs work out considerably cheaper per gram of carbohydrate than individually wrapped gels — and generate a fraction of the packaging waste. If you'd rather try before committing, the Taster Pack lets you test them on your next long run first.
The best running snacks for long training runs are the ones you'll actually eat, at the intervals you've actually planned, week after week. Sort your fuelling in training and race day becomes a rehearsed routine rather than a gamble. Stock up, head out, and make the last hour of your long run the strongest part — not the part you survive.
