Training plans · Marathon
16-week marathon training plan
Sixteen weeks is the most common marathon block. It is long enough to build real endurance from a solid base, and short enough to stay focused. Below is a complete sample plan for a runner aiming at 3:45 off a 1:46 half marathon. Under it, the same generator opens pre-filled, so you can swap in your own race date, goal and recent result.
The plan at a glance
Pfitzinger-style: High mileage, lactate-threshold runs, medium-long runs. 21 quality sessions in total, with every fourth week lighter and a taper into race day.
Week by week
| Week | Phase | km | Key sessions | Long run |
|---|---|---|---|---|
| 1 | base | 55 | Threshold run 6.6 km | 15.3 km |
| 2 | base | 58 | Threshold run 7 km | 16.6 km |
| 3 | base | 61 | Threshold run 7.3 km | 17.9 km |
| 4 | base | 51 | Threshold run 6.1 km | 13.7 km |
| 5 | base | 67 | Threshold run 8 km | 20.6 km |
| 6 | build | 70 | Threshold run 8.4 km, Intervals 8.4 km | 21.9 km |
| 7 | build | 73 | Threshold run 8.8 km, Intervals 8.8 km | 23.4 km |
| 8 | build | 60 | Threshold run 7.2 km, Intervals 7.2 km | 17.4 km |
| 9 | build | 78 | Threshold run 9.4 km, Intervals 9.4 km | 25.8 km |
| 10 | build | 81 | Threshold run 9.7 km, Intervals 9.7 km | 27.3 km |
| 11 | peak | 84 | Goal-pace run 10.1 km, Intervals 10.1 km | 28.9 km |
| 12 | peak | 70 | Goal-pace run 8.4 km, Intervals 8.4 km | 21.9 km |
| 13 | peak | 90 | Goal-pace run 10.8 km, Intervals 10.8 km | 32 km |
| 14 | taper | 68 | Easy running | 21 km |
| 15 | taper | 52 | Easy running | 14.1 km |
| 16 | taper | 36 | Easy running | Race day |
Training paces
Set from a recent half marathon result, not the goal. Enter your own in the generator and they update.
- Easy6:01/km
- Marathon5:14/km
- Threshold4:54/km
- Interval4:28/km
- Repetition4:17/km
- Goal race5:20/km
Who a 16-week plan suits
Runners who already run four or five days a week and can cover 15–20 km comfortably on a weekend. Sixteen weeks assumes that base exists. Its first month extends the base rather than creating it from nothing.
If your longest recent run is under 10 km, give yourself 18–20 weeks instead. If you are coming straight off a half marathon block, 12 weeks can be enough.
It is not a plan for your first weeks of running. The sample starts at 55 km a week. If you run 25 km a week now, choose the beginner tier in the generator, or a longer plan.
How the 16 weeks are spent
Weeks 1–5 are base. Volume rises from 55 to 67 km, with one threshold run a week. Weeks 6–10 are build, and a second quality day of intervals joins in. Weeks 11–13 are peak: the threshold run becomes a goal-pace run, and the long run reaches 32 km in week 13.
Weeks 14–16 are the taper: 68 km, then 52, then 36 including the race. That last week is about 40% of the peak.
Weeks 4, 8 and 12 drop volume by a fifth. Those recovery weeks are where the previous three weeks of work are absorbed. Resist the urge to make them up.
The peak week, day by day
Week 13 is the biggest week of the sample, at 90 km. Monday is rest. Tuesday, Thursday and Saturday are 12 km easy runs at about 6:01/km.
Wednesday is a 10.8 km goal-pace run at 5:20/km. Count the warm-up inside that distance. Friday is 10.8 km of intervals, with the fast repeats at about 4:28/km and easy jogs between them. Sunday is the 32 km long run, at easy pace.
If that week leaves you flat for days, the plan is too big for you right now. Drop to the beginner tier, which tops out lower, rather than skipping sessions at random.
If you miss a week or get ill
Miss a few days? Carry on from where the plan is. Don’t try to fit the missed sessions in later.
Out for a week or more, especially with a fever? Come back with easy running only, for at least as many days as you were ill. Then repeat the last full week you completed before moving on.
If it happens in the taper, rest and don’t worry. A week off three weeks out costs far less than training through an illness.
Frequently asked questions
Is 16 weeks enough to train for a marathon?
For a runner with a consistent base of 30–40 km a week, yes. Sixteen weeks covers a full base, build, peak and taper. Newer runners do better with 18–20 weeks, so the long run can grow more gradually.
How long is the longest run in a 16-week marathon plan?
In this sample it is 32 km, in week 13, three weeks before race day. Most intermediate plans top out between 30 and 35 km.
Can I start a 16-week plan with fewer weeks to go?
Yes. Enter your real start and race dates in the generator and it compresses the phases to fit. It warns you if the window is shorter than we would recommend.