Half Marathon Race Day Checklist: The Complete UK Guide (2026)
From the night before to the finish line, everything you need to do on half marathon race day. The honest UK checklist with our interactive race day planner.
TL;DR
Race day success starts the night before. Lay out your kit, eat a familiar carb-led dinner, hydrate steadily, and aim for a calm bedtime routine. On race morning, eat a tested breakfast around three to four hours before the gun, sip water, arrive with at least 60 minutes to spare, and warm up with five minutes of easy jogging plus dynamic drills. Pace your first 5K slower than goal, take a gel at miles 4, 8, and 11, break the race into mental thirds, and trust the work. Use our hour-by-hour planner below to build your exact race day timing.
The night before: set yourself up to win
The single biggest race day mistake is treating the night before like the start of race day. By the time the alarm goes off, the work is done. What you eat, how you sleep, and how organised your kit is the night before sets the tone for everything that follows.
Carb load, but keep it familiar
For a half marathon, you do not need the full week-long carb loading protocol used for the full distance. What you do need is a dinner that is heavier on carbs than usual, light on fat and fibre, and totally familiar. Think pasta with a simple tomato sauce, a rice bowl, jacket potato with beans, or sourdough toast with honey. This is not the night to try the new Thai place. Aim to finish eating by around 7pm so you have time to digest properly before bed.
Lay your kit out the night before
Lay everything out in the order you will put it on. This sounds basic, but it removes a huge amount of morning brain fog and stops the panic of a missing safety pin at 6am. Pin your race number on the night before, charge your watch, and bag up your gels and post-race snack.
Hydrate steadily, not heavily
Sip water through the evening rather than chugging a litre at bedtime. You want to wake up well hydrated, not bursting at 3am. A glass of water with dinner and another before bed is plenty for most runners. If you have been training all summer in heat, add a pinch of salt to one of those glasses.
Sleep matters, but do not panic if it is poor
Nerves often mean a broken sleep the night before a race. The good news is that research consistently shows performance is protected by your sleep over the previous fortnight, not just the night before. Get to bed an hour earlier than usual, switch off screens, and accept that you may toss and turn. You will still run your race.
Race morning: a tested routine wins
Your race morning routine should look almost identical to your longest training run morning. Nothing new on race day is the golden rule.
Eat three to four hours before the gun
For most UK half marathons with a 9am or 10am start, this means a 6am or 7am breakfast. Choose something you have eaten before a long run. Porridge with a banana and honey is the classic. A bagel with jam and a banana works. Two pieces of toast with peanut butter and honey is fine. The aim is around 1g of carbohydrate per kg of bodyweight: roughly 60 to 80g of carbs for most runners.
Coffee timing
If you train with caffeine, have caffeine. If you do not, race morning is not the time to start. For most runners, a coffee with breakfast around 90 minutes to 2 hours before the start gives the lift without the bathroom panic.
Pack your bag the night before
Race kit on. Tracksuit or old throwaway layer over the top. Bag with post-race kit, snack, phone charger, foil blanket if it is cold, and any post-race recovery clothes. Drop bag goes in early so you can focus on warming up.
The non-negotiable kit list
- Race number with safety pins (pinned on the night before)
- Timing chip attached to your shoe (check it twice)
- Running shoes you have already run a long run in (never new)
- Socks you have tested on a long run
- Shorts or leggings, plus chosen top layer
- Sports bra (women: tested on long runs only)
- Anti-chafe balm (thighs, nipples, underarms)
- Gels: at least 3 for a half marathon, plus a spare
- GPS watch, charged the night before
- Throwaway layer for the start line in case of cold
- Hat or visor if sunny, gloves if cold
- Bin bag or poncho if rain is forecast
- Travel route and start time written down (do not rely on phone signal)
- Post-race kit in the bag drop bag
The warm-up that actually works
The half marathon warm-up is shorter than you think. Five minutes of very easy jogging, followed by a round of dynamic drills, is plenty. You are not trying to get tired before the race starts.
A typical pre-race warm-up: five minutes of slow jogging starting around 60 minutes before the gun, followed by leg swings, walking lunges, high knees, and a few 20-second strides at goal pace. Finish by stripping off your throwaway layer and getting in the start pen at least 15 minutes before the off.
Start line strategy
Line up by goal time. Every UK half marathon now has pacers or a coloured pen system. Pick the pen that matches your goal pace, not the pen that matches your hopes. Lining up too far forward forces you to either weave dangerously or get boxed in and run the first mile too fast. Lining up too far back wastes 20 to 40 seconds dodging walkers.
When the gun goes, do not sprint. The clock for chip-timed races starts when you cross the line, not when the gun fires. Walk forward calmly, jog when the runners ahead jog, and let your race start naturally.
Pacing strategy: first 5K slower than goal
The single best predictor of a strong half marathon is a controlled first 5K. Adrenaline and fresh legs will make goal pace feel suspiciously easy. Resist. Aim for your first 5K to come in 10 to 20 seconds per mile slower than your overall goal pace, then settle into your target pace for miles 4 through 10, and let the last three miles take care of themselves.
Runners who hit goal pace from the gun typically blow up between miles 9 and 11. Runners who hold back early almost always close strong. A negative split, where the second half is faster than the first, is the gold standard for a half marathon.
Fuelling: the gel schedule that works
A half marathon is the shortest race where fuelling on the run actually matters for most people. If you are running longer than around 75 minutes, your body will benefit from carbohydrates during the race.
The standard UK approach is one gel every four miles, typically taken at mile 4, mile 8, and mile 11. Each gel delivers around 20 to 30g of carbs. Wash them down with a few sips of water from the next aid station rather than from a sports drink, which can double up on sugar and upset your stomach.
Practise your gels on long runs. The biggest cause of mid-race stomach issues is taking a brand or flavour you have never tried. Race day is not the day for that new salted caramel flavour.
Mental thirds: how to run the race in your head
Break the 13.1 miles into three mental chunks. The first third (miles 1 to 4) is for settling: hold back, breathe, smile at the crowds. The middle third (miles 5 to 9) is for working: lock into goal pace, focus on form, take your gels on schedule. The final third (miles 10 to 13.1) is for grit: this is where the work shows. Pick targets one runner at a time, count down the miles, and trust that the discomfort is normal.
A useful trick: when it gets hard around mile 10, remind yourself that you only have a parkrun left. Most UK runners have run a thousand parkruns. You can run one more.
The finish line and recovery
Keep walking after you cross the line. Stopping suddenly causes blood to pool and can make you feel dizzy or sick. Walk for five minutes, grab your medal and finisher t-shirt, and head to the bag drop.
Within 30 minutes, eat something with carbs and protein. A banana and a recovery shake, a flapjack and a chocolate milk, or just a real meal if the finish festival has food. This 30 minute window is when your body absorbs nutrients fastest.
Stretch lightly if you want, but do not force a full stretching routine on legs that have just done 13.1 miles. A warm shower, dry clothes, and a proper meal within two hours matters more than any post-race stretch.
The most common race day mistakes
- Trying new kit, shoes, food, or gels on race day. Everything you wear and consume should have been tested in a long training run.
- Going out too fast. The first mile of a half marathon should feel comfortable, almost too easy.
- Skipping the warm-up. Five minutes of jogging is non-negotiable.
- Drinking too much pre-race. A pint of water before the gun guarantees a portaloo queue at mile 3.
- Forgetting anti-chafe. Bloody nipples and chafed thighs are the most common avoidable race day injuries.
- Checking the watch every 30 seconds. Glance every mile. Trust your pacing.
How Edge fits into your race day
The Edge app is built for runners who want structured training without a personal coach. The native Apple Watch app gives you race-day timing, splits, and a clean lock-screen view of your current pace, mile time, and projected finish. If you train with Garmin or Coros, Edge pushes your structured workouts straight to your device, so race-week sessions show up exactly as planned. Over 17,000 members use Edge to train their way, and our half marathon plans are designed to fit around life, work, and family, not the other way round. Fun, flexible training that fits your life.
Frequently asked questions
What time should I eat breakfast before a half marathon?
Aim to finish breakfast three to four hours before the start gun. For a 9am UK race, that means eating by 5:30 to 6am. This gives your body time to digest properly and turn the food into available energy without sitting heavy in your stomach.
How many gels should I take in a half marathon?
Most runners take three gels for a half marathon: typically at mile 4, mile 8, and mile 11. This gives you 60 to 90g of carbs across the race, which research shows is the sweet spot for endurance runs lasting between 90 minutes and two hours. Pack a fourth gel as a spare in case you drop one.
What should I wear for a half marathon?
Wear what you have already tested on a long training run. Shorts or leggings, a vest or t-shirt, tested socks, and shoes that have already covered at least 30 to 50 miles. Add a throwaway layer for the start in cold weather, gloves if it is under 8C, and a hat or visor in strong sun.
How early should I arrive at the start line?
Arrive 60 to 75 minutes before the gun. This gives you time for bag drop, the portaloo queue (allow 20 to 25 minutes at a major UK race), a five-minute warm-up jog with drills, and getting into the right start pen 15 minutes before the off.
Should I run the first mile at goal pace?
No. Your first mile should be 10 to 20 seconds slower than your overall goal pace. The first mile of a half marathon should feel comfortable and almost too easy. Runners who go out at goal pace from the gun typically slow significantly in the final 5K. A negative split, where the second half is faster than the first, is the gold standard.
What if I have a bad night of sleep before the race?
Do not panic. Research shows performance is protected by your sleep over the previous fortnight, not just the night before. As long as you have slept well in the week leading up, a single broken night will not stop you running your race. Caffeine will cover most of the gap on the morning.
