Quick summary
- Goal pace: 5:38 per km (9:05 per mile) for a 3:58 finish, two minutes of buffer under 4:00.
- Who it's for: runners who can already run a 10K in about 52 minutes or a half marathon in about 1:55, on 30–40 km a week.
- The plan: 16 weeks, four phases, peaking at 64 km a week with a 29 km long run.
- The three sessions that matter: one quality workout, one long run and one marathon-pace run each week. Everything else is easy.
- Fueling: 60–90 g of carbohydrate per hour from the start, about one gel every 30–35 minutes.
Breaking four hours is the most popular marathon goal in the world, and the one most often missed by a few minutes. Most runners who miss it don't lack fitness. They run the first half too fast, under-fuel, or arrive at the start line tired from a plan that was too hard in the wrong places.
This plan fixes all three. It is built around a single principle: most of your running should feel easy, so that three key sessions a week can be done properly. Below you'll find every pace, every week and a race-day split chart you can print.
How this plan is built
The structure follows established endurance-training principles: about 80% of weekly running at easy effort, a gradual volume increase of no more than about 10% per week, a lower-volume recovery week every fourth week, and race-specific marathon-pace work concentrated in the final eight weeks.
Paces are set from a target finish of 3:58, which corresponds to roughly a 24:40 5K, a 51:15 10K or a 1:53 half marathon. If your recent race times are slower than these, run the plan anyway but set your paces from your current fitness, then re-test at the week 8 time trial. Our marathon pace chart lists the paces for every other finish time.
Your training paces
Every session in the plan uses one of five zones. Set your watch to show these as pace alerts.
| Zone | Per km | Per mile | Feels like | Used for |
|---|---|---|---|---|
| Easy | 6:40–7:20 | 10:44–11:48 | Full conversation | Most weekly running |
| Long run | 6:20–6:50 | 10:12–11:00 | Comfortable, chatty | Weekend long run |
| Marathon pace (MP) | 5:35–5:40 | 8:59–9:07 | Controlled, short sentences | MP blocks |
| Threshold | 5:10–5:20 | 8:19–8:35 | Comfortably hard, a few words | Tempo runs |
| Interval | 4:45–4:55 | 7:39–7:55 | Hard, no talking | 800 m–1.6 km repeats |
If it's hot or humid, ignore pace and run easy days by effort (see marathon training in hot weather). Pace typically drops 10–20 seconds per km in 25°C+ heat, and fighting that is how runners overtrain.
The 16-week plan
Each week has three key sessions. Fill the remaining days with easy running or rest; four or five running days a week is enough.
Phase 1: Base (weeks 1–4)
Build the habit and the aerobic engine. Keep everything controlled.
Phase 2: Strength (weeks 5–8)
Longer long runs and the first marathon-pace work. Week 8 ends with a 10K time trial to check your paces.
Phase 3: Race-specific (weeks 9–13)
The hardest block. Long runs carry marathon-pace finishes so your legs learn goal pace on tired muscle.
Phase 4: Taper (weeks 14–16)
Volume drops by about 20%, 40% and 65%. Intensity stays, so you keep sharpness while fatigue clears. Our guide to how to taper for a marathon explains why.
| Week | Weekly km (mi) | Quality session | Marathon-pace work | Long run |
|---|---|---|---|---|
| 1 | 40 (25) | 3 × 8 min threshold, 2 min jog | — | 16 km easy |
| 2 | 44 (27) | 6 × 800 m interval, 400 m jog | — | 18 km |
| 3 | 47 (29) | 20 min continuous threshold | — | 20 km |
| 4 | 38 (24) | 8 × 20 s strides | — | 16 km (recovery week) |
| 5 | 50 (31) | 5 × 1 km interval, 2 min jog | 5 km MP | 22 km |
| 6 | 53 (33) | 2 × 15 min threshold | Last 5 km of long run at MP | 24 km |
| 7 | 56 (35) | 4 × 1.6 km threshold | 8 km MP within a 14 km run | 26 km |
| 8 | 45 (28) | 10K time trial or race | — | 18 km (recovery week) |
| 9 | 58 (36) | 6 × 1 km interval | Last 8 km of long run at MP | 27 km |
| 10 | 60 (37) | 3 × 3 km threshold | 12 km MP within an 18 km run | 24 km |
| 11 | 63 (39) | 2 × 20 min threshold | Last 10 km of long run at MP | 29 km or 3 hours, whichever comes first |
| 12 | 50 (31) | Half-marathon tune-up race (target 1:52–1:55) | — | The race is the long run |
| 13 | 64 (40) | 5 × 1.6 km threshold | 16 km MP within a 24 km run | 29 km, last 13 km at MP |
| 14 | 50 (31) | 4 × 1 km interval | 10 km MP | 22 km |
| 15 | 38 (24) | 6 × 400 m relaxed, 8 × 20 s strides | 3 × 2 km MP | 16 km |
| 16 | 22 (14) + race | 3 × 1 km MP on Tuesday | Race day | Marathon |
Race-day pacing: the split chart
The goal is an even effort, not a fast start. Bank no time in the first 10 km: every minute "banked" early usually costs more after 30 km. Aim to pass halfway at 1:59:00 and feel like you're holding back.
| Checkpoint | Target split (5:38/km) | Effort check |
|---|---|---|
| 5 km | 28:12 | Too easy. Good. |
| 10 km | 56:24 | Still conversational in short sentences |
| 15 km | 1:24:36 | Gels taken on schedule |
| Half (21.1 km) | 1:59:00 | Controlled; you could speed up but don't |
| 25 km | 2:21:01 | Settle in; refocus on form |
| 30 km | 2:49:13 | The race starts here |
| 35 km | 3:17:25 | Hold pace; count down one kilometre at a time |
| 40 km | 3:45:37 | Anything left, use it now |
| Finish (42.2 km) | 3:58:00 | Sub-4 with two minutes to spare |
GPS watches usually read long in big-city races because you can't run the exact racing line, often by 0.3–0.8 km over 42 km. Pace off the official kilometre markers, not your watch's lap distance, or you'll finish behind your watch.
Fueling: how many gels for a sub-4 marathon
A sub-4 marathon burns roughly 2,600–3,000 kcal for most runners, far more than your glycogen stores can cover. Running low is what causes "the wall".
- Carbohydrate: 60–90 g per hour. Most gels contain 20–40 g, so plan on 6–8 gels across the race, or about one every 30–35 minutes, starting 30–40 minutes in.
- Fluid: 400–800 ml per hour, adjusted to heat and your sweat rate. Weigh yourself before and after a long run to estimate yours.
- Sodium: 300–600 mg per hour in warm conditions, from electrolyte drinks or capsules.
- Practise it: use your exact race-day gels on every long run from week 6. The gut adapts to carbohydrate intake the way muscles adapt to training.
For a gel-by-gel timeline, see our marathon fueling plan.
The gear that matters for sub-4
You don't need much, but these four items directly affect your result.
| Gear | Why it matters for sub-4 | What to look for |
|---|---|---|
| GPS watch | Pace alerts keep you out of the red in the first half | Accurate GPS (multi-band), custom workouts, 20+ hours of battery |
| Heart-rate strap | Keeps easy days easy; wrist sensors lag during intervals | Chest strap with Bluetooth and ANT+ |
| Gels and electrolytes | Prevents the wall after 30 km | 25 g or more of carbohydrate per gel, a flavour you tolerate |
| Carry system | Lets you fuel on your schedule, not the aid stations' | No bounce and easy access at pace: a race belt or shorts with gel pockets |
Chafing and overheating end more sub-4 attempts in the final 10 km than a lack of fitness. Whatever you wear, wear it on your week 11 and week 13 long runs first. Our race-day kit checklist covers every weather.
Five mistakes that cost runners their sub-4
- Running easy days too fast. If your easy runs are within 45 seconds per km of marathon pace, you're too tired for the sessions that matter.
- Skipping marathon-pace work. Long slow runs alone don't teach your body what 5:38/km feels like at 30 km. The MP blocks in weeks 5–13 do.
- Starting 10–15 seconds per km too fast. It feels easy on race-day adrenaline. It isn't. Run the first 5 km at 5:40–5:45.
- Untested race-day kit. New shoes, new gels or a new top on race day is how blisters, gut problems and chafing happen. Nothing new on race day.
- Training through pain. Sharp or worsening pain that changes your stride isn't fatigue. Rest for two days and see a physiotherapist if it persists; a missed week costs far less than a missed race.
FAQ
What pace do I need for a sub-4 hour marathon?
You need to average 5:41 per km (9:09 per mile) to finish in exactly 4:00:00. Target 5:38 per km (9:05 per mile) for a 3:58 finish: the two-minute buffer covers GPS drift, aid stations and crowded starts.
How many kilometres a week should I run for a sub-4 marathon?
Most runners break four hours on 50–70 km (30–45 miles) a week at peak. This plan peaks at 64 km. More mileage helps only if you can absorb it without injury; consistency over 16 weeks matters more than any single big week.
Is 16 weeks enough to train for a sub-4 marathon?
Yes, if you start with a solid base: about 30–40 km a week and a recent 10K around 52 minutes or a half around 1:55. Starting from a lower base, add 6–8 weeks of easy running first.
What half marathon time do I need to run a sub-4 marathon?
A half marathon around 1:53–1:55 predicts a sub-4 marathon for most runners, provided the marathon training is completed. Race predictors assume you've done the long runs; without them, expect to finish slower than predicted.
Should I run 20 miles (32 km) before a marathon?
Not necessarily. For a sub-4 runner, 32 km takes around 3.5 hours, which adds fatigue without much extra benefit. This plan caps long runs at 29 km or 3 hours, whichever comes first, and adds marathon-pace finishes to make them race-specific.
Can a beginner run a sub-4 marathon?
A first-time marathoner can break four hours if they already have a strong running base and a 10K under about 52 minutes. Runners newer to the sport should aim to finish comfortably first, then chase sub-4 at their second marathon.
How many gels should I take during a sub-4 marathon?
Plan on 6–8 gels: one every 30–35 minutes, starting 30–40 minutes in, to reach 60–90 g of carbohydrate per hour. Practise the exact plan on long runs so your gut can handle it.
Bottom line
Sub-4 is rarely about talent. It's about running easy days easy, nailing three key sessions a week, practising your fueling, and starting the race slower than feels right. Follow the 16 weeks above, run your first 10 km at 5:40–5:45 per km, and you'll be passing people at 35 km instead of being passed.
This article is general training information, not medical advice. Check with a doctor before starting a new training programme, especially if you have a health condition.