TL;DR: A sub-4 marathon means running 26.2 miles in under 4 hours, which works out to an average pace of 9:09 per mile (5:41 per km). In the UK, the median marathon finish time sits around 4:35, so a sub-4 result puts you roughly in the top 30 percent of finishers. This guide gives you the honest 16-week plan, weekly mileage targets, the four key workouts that build sub-4 fitness, a UK pace table, race day pacing logic, and an interactive readiness check so you can see if you are ready to start. You will not find magic shortcuts here. You will find what actually works.
Who this plan is for
A sub-4 marathon is a serious target. It is not a beginner goal, and it is not the kind of result you can stumble into from low mileage. Before you start this plan, you should tick most of the boxes below. If you cannot tick them, your better move is a build phase first, then return to the sub-4 plan in your next race cycle.
- You can run five times per week without picking up niggles.
- You have finished a half marathon in under 1 hour 55 minutes within the last six months.
- Your current weekly mileage is 25 to 30 miles per week.
- You can comfortably run 10 miles in one go at a relaxed pace.
- You have no current injuries and you have not had a long lay-off in the last eight weeks.
- You have 16 weeks of clear runway before race day, with no big work or life disruptions you already know about.
If you are running three times a week, or your half marathon is over two hours, that is genuinely fine. It just means sub-4 is not the right goal for this cycle. Build the base first. Aim for sub-2 in the half. Then come back to this plan.
The sub-4 maths, in plain English
Sub-4 marathon means a finish time of 3 hours, 59 minutes, 59 seconds or faster. The marathon is 26.2 miles, or 42.195 km. To finish in under 4 hours, you need to average:
- 9 minutes 9 seconds per mile
- 5 minutes 41 seconds per km
That sounds tidy on paper. In reality you will not hit exactly 9:09 every mile. You will run some miles faster on flat sections, some slower up hills, and you will lose a few seconds at water stations. The honest target is to bank a small buffer in the first half so you can absorb the late-race slow-down most runners feel between mile 20 and mile 24. We will cover race day pacing later in the guide.
One more useful number. To average 9:09 per mile for 26.2 miles, your easy long runs need to feel a lot easier than 9:09. Most coaches put easy running around 10:30 to 11:30 per mile for a sub-4 hopeful. If every easy run is 9:30, you are not training easy, you are grinding. That is the biggest hidden reason people miss sub-4.
The full 16-week sub-4 marathon training plan
This is the honest plan. Five days of running, two rest days, and a gradual build to a peak of 40 to 45 miles per week before a three-week taper. Every week follows the same rhythm. Mondays and Fridays are rest. Tuesdays and Thursdays are easy. Wednesday is your midweek quality session. Saturday is either marathon-pace work or a threshold session. Sunday is the long run.
| Week | Tue | Wed | Thu | Sat | Sun long | Total miles |
|---|---|---|---|---|---|---|
| 1 | 4 mi easy + 4 strides | 5 mi with 3 mi at threshold | 4 mi easy | 5 mi easy | 10 mi easy | 28 |
| 2 | 4 mi easy + 4 strides | 6 mi with 4 x 1k at threshold | 4 mi easy | 5 mi easy | 12 mi easy | 31 |
| 3 | 5 mi easy | 6 mi with 3 mi marathon pace | 4 mi easy | 6 mi easy + 6 strides | 13 mi easy | 34 |
| 4 | 4 mi easy | 5 mi easy | 3 mi easy | 4 mi easy | 10 mi easy (cutback) | 26 |
| 5 | 5 mi easy + 4 strides | 7 mi with 5 x 1k at threshold | 5 mi easy | 6 mi with 4 mi marathon pace | 14 mi easy | 37 |
| 6 | 5 mi easy | 7 mi with 4 mi at threshold | 5 mi easy | 6 mi easy | 15 mi with last 3 at marathon pace | 38 |
| 7 | 6 mi easy + 6 strides | 8 mi with 6 mi marathon pace | 5 mi easy | 7 mi easy | 16 mi easy | 42 |
| 8 | 5 mi easy | 6 mi easy | 4 mi easy | 4 mi easy | 11 mi easy (cutback) | 30 |
| 9 | 6 mi easy + 6 strides | 8 mi with 6 x 1k at threshold | 6 mi easy | 8 mi with 5 mi marathon pace | 17 mi easy | 45 |
| 10 | 6 mi easy | 8 mi with 5 mi at threshold | 6 mi easy | 8 mi easy | 18 mi with last 5 at marathon pace | 46 |
| 11 | 6 mi easy + 6 strides | 9 mi with 7 mi marathon pace | 6 mi easy | 7 mi easy | 20 mi easy | 48 |
| 12 | 5 mi easy | 6 mi easy | 4 mi easy | 4 mi easy | 12 mi easy (cutback) | 31 |
| 13 | 6 mi easy + 6 strides | 9 mi with 6 x 1k at threshold | 6 mi easy | 9 mi with 6 mi marathon pace | 20 mi with last 6 at marathon pace | 50 |
| 14 (taper) | 5 mi easy + 4 strides | 7 mi with 4 mi marathon pace | 5 mi easy | 6 mi easy | 14 mi easy | 37 |
| 15 (taper) | 4 mi easy | 5 mi with 3 mi marathon pace | 4 mi easy | 4 mi easy | 10 mi easy | 27 |
| 16 (race) | 4 mi easy + 4 strides | 3 mi easy | 2 mi easy | 2 mi easy + 4 strides | RACE DAY 26.2 | 37 |
Mileage builds for three weeks, then a cutback week eases the load by roughly 30 percent. This pattern repeats four times before the taper. Cutback weeks are not optional. They are the weeks your body actually absorbs the training.
The four key workouts explained
Most weeks have one Wednesday quality session and one Saturday quality session. The Sunday long run is always there too. Across the plan you cycle through four workout types. Get these right and the rest of the plan looks after itself.
1. Marathon-pace tempo runs
The most specific workout in the plan. You run at your goal marathon pace, which is 9:09 per mile or 5:41 per km, in the middle of a longer run. A typical session is 9 miles total with 6 miles at marathon pace in the middle, sandwiched between a 1.5-mile warm-up and a 1.5-mile cool-down. The point is to make 9:09 per mile feel boring and repeatable. On race day, that pace needs to feel like home.
2. The long run with marathon-pace finish
Sundays are mostly easy and conversational, but a few times in the plan you finish the last 3 to 6 miles at marathon pace. This is the single best predictor of race day performance. Running hard miles on already tired legs is the closest a workout can get to mile 22 of the race itself.
3. Threshold intervals and threshold tempo
Threshold work is run at roughly 10K to half-marathon pace, which for a sub-4 hopeful is around 8:00 to 8:20 per mile. You will do these two ways. Continuous threshold runs, like 4 miles at threshold pace. And threshold intervals, like 5 x 1k at threshold with 90 seconds jog recovery. Threshold work lifts your ceiling so that marathon pace sits well below it.
4. The 20-mile long run
You will hit one 20-miler in week 11, then a second 20-miler with marathon-pace finish in week 13. Two is enough. More than that pushes recovery cost too high, and the marginal fitness gain is small. The 20-mile long run is a confidence builder as much as a physical one. Once you have done it, you know your legs can carry you. The last 6.2 miles on race day are powered by training, taper, fuelling and crowd noise.
Your UK pace targets table
You need to know more paces than just 9:09. Easy running, threshold and 5K pace all sit at specific levels. Here are the rounded targets for a sub-4 hopeful.
| Effort | Per mile | Per km | Feel |
|---|---|---|---|
| Easy run | 10:30 to 11:30 | 6:32 to 7:09 | Full conversation possible |
| Long run (most of it) | 10:00 to 11:00 | 6:13 to 6:50 | Comfortable, nose breathing possible |
| Marathon pace | 9:09 | 5:41 | Steady, focused, short sentences |
| Threshold | 8:00 to 8:20 | 4:58 to 5:11 | Comfortably hard, a few words at a time |
| 5K pace | 7:30 to 7:50 | 4:40 to 4:52 | Hard, one or two words only |
Sub-4 readiness check and pacing calculator
Use this calculator to see if you are ready to start a sub-4 plan, and to print out your per-mile and per-km splits.
Strength and mobility
Two short strength sessions per week make a real difference for sub-4 hopefuls. We are talking 20 to 30 minutes, not bodybuilder marathons. Focus on single-leg work like split squats, step-ups and single-leg deadlifts. Add a glute bridge variant, a calf raise variant, and a short core circuit. Slot these in after an easy run, not before a quality session.
Mobility is best done in five-minute doses, daily, rather than one big stretch session per week. Hips, ankles and thoracic spine are the three areas that pay back the most for runners building marathon mileage.
The taper, explained
The three-week taper is not a holiday. It is a controlled reduction in volume while you keep some intensity in your legs. Volume drops roughly 20 percent in week 14, another 25 percent in week 15, and roughly 60 percent in race week. Pace work stays in the plan, just shorter. Your long run shrinks, but it does not disappear until race week.
Most runners feel terrible in week 15. Sluggish, twitchy, and convinced they have lost fitness. This is normal. Your body is repairing micro-damage from the 16 weeks of load. Trust the plan. The fresh legs arrive in race week.
Race day pacing with a negative split bias
The fastest, most enjoyable way to run sub-4 is a small negative split, where your second half is a touch faster than your first. Aim to run the first 10K about 10 to 15 seconds per mile slower than goal pace, lock into 9:09 from 10K to halfway, and then trust your training to hold or slightly improve in the second half.
Here are mile splits for a 3:58 finish, which gives you a 2-minute buffer on the official sub-4 line. This is the sensible target.
| Section | Target average per mile |
|---|---|
| Miles 1 to 6 | 9:15 to 9:20 |
| Miles 7 to 13 | 9:05 to 9:10 |
| Miles 14 to 20 | 9:00 to 9:08 |
| Miles 21 to 26.2 | 9:00 to 9:10, hold on |
Race day fuelling
Sub-4 means roughly 4 hours of running, which is well past the point where your body runs out of stored carbohydrate. You need to fuel during the race. The current evidence supports 60 to 90 grams of carbohydrate per hour for trained marathon runners, taken in small regular doses rather than in two big hits.
- Take a gel every 30 minutes from minute 30 onwards. That is roughly 7 gels across the race.
- Aim for a gel that delivers at least 25 to 30 grams of carbohydrate.
- Drink small amounts of water or sports drink at every aid station, not big gulps.
- Practise the exact gels, the exact drink and the exact timing during your long runs from week 7 onwards. Do not try anything new on race day.
Common reasons people miss sub-4
Most failed sub-4 attempts fail for one of the reasons below. None of them are fitness problems. They are decision problems.
- Easy runs too fast. If your easy pace is closer to 9:30 than to 10:30, your legs never recover, and your quality sessions suffer.
- Skipping the cutback weeks. The cutback is the week the training works. Skipping it gives you fatigue, not fitness.
- Going out too fast. A 4-minute positive split is a sub-4 killer. Banking time in the first 10K rarely survives the last 10K.
- Under-fuelling. Three gels for a 4-hour marathon is not enough. Aim for at least 6 to 7.
- Trying new kit on race day. New shoes, new shorts, new gels and a new sports drink is a recipe for a bad day. Test everything in training.
- No plan B for the weather. If race day is hot, sub-4 may not be on. Adjust to a sensible target on the start line rather than melting at mile 18.
How Edge fits into a sub-4 build
This is the honest part. Edge is not a stamp-and-go sub-4 plan. There is no "Sub-4 plan" button in the app, and Edge does not auto-prescribe sub-4 paces or enforce race-day splits. What Edge does is something different and, for many runners, more useful.
When you sign up, a real human coach builds your starting plan within 24 hours. You tell them at signup that your goal is sub-4 marathon and your race date, and they hand-build the week around your current pace, your real schedule and that goal. Marathon-pace tempos and the long run go in the right places, around your work and life. Not generated by an algorithm, written by a coach.
From there, you get general strength and mobility sessions, coach video demos for the key movements, lean voice prompts on your runs so you do not have to keep looking at your watch, and direct sync with Strava, Garmin, Apple Watch and Coros so the plan and your data live in one place. The Flexi Swap feature lets you move sessions around without breaking the plan. Edge AI is there for quick questions, and you can speak to the coaches for the bigger ones.
Edge is £19.99 per month or £119.99 per year, with a free 7-day trial on the 6-month and annual plans. More than 17,000 UK members already train with Edge. Making fitness feel good for everyone.
Frequently asked questions
What pace do I need to run a sub-4 marathon?
You need to average 9 minutes 9 seconds per mile, or 5 minutes 41 seconds per km, for the full 26.2 miles. To leave a small buffer, target a 3:58 finish, which is closer to 9:05 per mile.
How many miles per week should I run to break 4 hours?
Peak weeks of 40 to 45 miles per week are the sensible range. Most weeks sit between 30 and 45 miles. You do not need to top 50 miles to break 4 hours.
Is a sub-4 marathon hard?
It is a meaningful target. In the UK, the median marathon time is around 4 hours 35 minutes, which means a sub-4 result sits roughly in the top 30 percent of finishers. With a good base, 16 focused weeks and sensible pacing, it is realistic for many committed club runners.
What half marathon time do I need before starting a sub-4 plan?
A half marathon PB under 1 hour 55 minutes is the honest benchmark. Under 1:50 makes the build significantly more comfortable. If your half is over 2 hours, build the base for one more cycle before chasing sub-4.
How long is a sub-4 marathon plan?
16 weeks is the sweet spot. Long enough to build mileage and key sessions, short enough that life does not derail it. The last 3 weeks are a taper, where volume drops while pace work stays sharp.
Does Edge have a sub-4 marathon plan?
Edge does not have a "Sub-4 plan" button. Instead, when you sign up you tell the Edge coaching team your sub-4 goal and race date. They hand-build the starting plan around your current pace, your schedule and that goal within 24 hours. Marathon-pace work, long runs and threshold sessions go in the right places. You can adjust through Flexi Swap, sync your watch and message the coaches as the build progresses.
