Sixteen weeks to the start line

This plan gets you to the marathon start line genuinely fit, and it puts you on the sub-3 track rather than the just-finish track. That's a real distinction. A typical first-marathon plan peaks at 45 km a week with no pace work and produces someone who survives 42 km. This one peaks at 66, trains marathon pace directly, and produces someone who races it.

What it will not do is deliver sub-3. Sub-3 is 4:16 per kilometre held for 42.2 km, and the people who run it are training 70–100 km a week for years, not one block. Your realistic finish here depends almost entirely on the week-8 10K test, and the plan tells you how to convert that into a target when you have it.

Treat this as marathon number one of three or four. The sub-3 attempt is the one at the end of that sequence, and the fastest honest route to it runs straight through this block.

All of it easy. Run/walk it if you need to — 8 minutes running, 1 walking, and the walk counts toward the distance. At the end of week D, run 8 km continuously. If it's conversational, start week 1. If it isn't, repeat weeks C and D. Nothing is lost by taking four extra weeks; a lot is lost by breaking in week 6.

Every run in this plan has both a distance and a pace band. Find the marathon time you're aiming at, and read across. Until the week-8 10K test gives you real data, aim at the row you think is plausible and err one row slower.

Take your 10K time and multiply by 4.7. A 45:00 10K predicts 3:32; a 40:00 predicts 3:08.

Then add 5–10% back on, because that formula assumes marathon-specific endurance you won't have yet in your first block. A 45:00 10K realistically means 3:40–3:55 on the day. Set your MP from the realistic number, not the predicted one. Training at a pace your endurance can't support is how first marathons blow up at 32 km.

The Thursday medium-long run is the most important addition here. It's Pfitzinger's signature session and it's what makes this a marathon plan rather than a long-run-plus-filler plan. It builds mitochondrial density and capillary growth without the recovery cost of a second long run, and it's the main reason this block peaks at 66 km instead of 45.

The week opening with a run means four run days in a row — Saturday long, Sunday recovery, Monday easy, Tuesday quality. That's deliberate and safe, because Sunday and Monday are the two easiest runs of the week, and the mid-week rest now lands on Wednesday, straight after the quality day, which is exactly where you want it.

One quality day, four easy days. That ratio is Patrick Sang's, and it's not up for improvement. The failure mode of every ambitious amateur is that the easy days creep up to medium and the hard day gets softer, until you're running five identical medium runs and plateauing for years.

Numbers are kilometres. Warm-up and cool-down are included in the quality-day figure. Unless a cell says otherwise, the run is easy throughout. Wednesday and Friday are always rest.

No threshold work yet. The job of block 1 is to absorb five runs a week and a Thursday medium-long without accumulating damage. If anything hurts in these four weeks, the rest of the plan is not going to fix it.

Week 8 is the calibration point of the whole block. Saturday replaces the long run with a 10 km time trial or, better, an actual 10 km race: 3 km warm-up, 10 km all out and evenly paced, 1 km cool-down. Every pace from week 9 onward comes off this number. Keep Tuesday and Thursday genuinely easy that week so the result measures your fitness rather than your fatigue.

This is where the plan stops being generic endurance work and starts being marathon training. Marathon pace appears in two places at once — as its own session on Tuesday, and as a finish to the long run on Saturday. Running MP on already-tired legs is the specific adaptation the race demands, and it's the thing most first-timers have never practised.

Week 13 is the hardest week of your life so far and week 14 starts giving it back. The taper is not a reward and it is not optional — the fitness is built by the end of week 13, and the last three weeks exist purely to shed fatigue. You will feel sluggish, heavy and undertrained through weeks 15 and 16. That is what a working taper feels like. It is not a signal to add anything.

Week 16: Monday 8 km easy with 4 strides, Tuesday 6 km easy, Wednesday rest, Thursday 5 km easy, Friday rest, Saturday 4 km shakeout, Sunday race.

All of them are built the same way: 2–3 km warm-up → the work → 1–2 km cool-down. Recovery between blocks is easy jogging, not standing still. The warm-up and cool-down are inside the distance shown in the table.

• Under 60 minutes: water only.
• Over 75 minutes: start fuelling. Begin at 30–40 g of carbohydrate per hour from week 5, taking the first one at 30 minutes rather than when you feel empty.
• From week 9: build toward 60–90 g/hour on every long run. Use a 2:1 glucose-to-fructose product — glucose transport saturates around 60 g/h, and fructose opens a second pathway that gets you past it.
• The gut is trainable and it needs training. Untrained, most people tolerate about 60 g/h. Two weeks of deliberate practice measurably improves absorption and reduces stomach trouble. The best predictor of race-day GI problems is not having rehearsed.
• Fluid: 400–800 ml/hour with 300–600 mg sodium per hour, more in heat.
• Before long runs: 1–2 g carbohydrate per kg bodyweight two hours out. At 70 kg that's 70–140 g.
• Use exactly what the race hands out, or carry your own for the whole race. Race day is not the day to discover a new gel.

Finish this block and you'll have done something most people who talk about marathons never do, and you'll have a real marathon time to build on. The route from there:

• Marathon 2 — the same shape, peaking at 80–85 km with two quality days instead of one. Aim to take 15–25 minutes off.
• Marathon 3 — Pfitzinger 18/70 territory, 6 days a week, 90–100 km peak. This is the block where sub-3 becomes a live question rather than an aspiration.

The markers to watch on the way: 10K under 39 minutes, half marathon under 1:25, and 70–100 km a week sustained for twelve weeks or more. Hit those three and sub-3 is a matter of picking a flat race on a cool day. Miss them and no plan on earth delivers it.