Sample plan

Marathon training plan for 3:45

Marc's second marathon, aiming at 3:45.

Marc is 41 and has run for six years, but comes off a thin summer: four days a week, around 25 km with a 14 km long run, and a 48:00 10K. His first marathon, two years ago, was 3:58. Fifteen weeks to a winter marathon and a 3:45 target — which is a lot to ask of 25 km a week, and the coach says so.

Built by Tuin on 8 September 2026
Shown from this week, so it reads like a plan starting today — every weekday, distance and session is exactly as it was written.

The runner is made up. The plan is not: it is exactly what Tuin built from these numbers, through the same door every athlete's first plan goes through. It was written in Spanish — the other two languages are translated word for word, never renumbered, and strength exercises are named from a standard glossary so they read the same everywhere.

Why this plan looks like this

Twenty-five kilometres a week is a thin base for a 3:45, and the coach says so in its own words rather than quietly writing a plan that pretends otherwise. What it does instead is spend the first third of the block rebuilding the week Marc used to run, and only then start asking for marathon pace — which is why the early weeks look unambitious and the last third does not.

What the coach was told

Goal
Winter marathon
Race day
24 January 2027
Distance
42.2 km
Target
3:45:00
Runs per week
4
Weekly volume
~25 km
Longest run
14 km
Recent effort
10 km · 48:00
Threshold pace
4:50/km

The eight weeks before

Weekly kilometres the coach read before writing a single session — the runs it built on.

25
25
26
26
17
28
28
26

What the coach said, handing it over

Alright, here's your first plan toward the winter marathon (3:45:00, 24 Jan). First things first, the assumptions I've made:

- From your September 10K (28:00, 4:48/km) I'm taking that pace as your threshold reference — the rest of your paces (easy runs ~5:45-6:00/km, marathon pace 5:20/km, 10K pace 4:48/km) all come from there. - You're coming off ~25 km/week with a longest run capping out at 11 km, so I'm starting right there and building gradually — no big jumps. - Since you asked for conservative mode (cruise), the plan ramps up volume slowly with recovery weeks every 3-4 weeks; if in January we notice we need more punch to dip under 3:45, I'll flag it early and we can turn up the pace a bit. - Tomorrow Wednesday isn't one of your race days (Tuesday/Thursday/Saturday/Sunday), so I've put your strength session there (1x/week like you asked) and your first run lands on Thursday — I'm keeping your routine instead of forcing you to run outside your days. - Race week (19–24 Jan): threshold work on Tuesday, easy run with a marathon-pace stretch on Thursday, short activation on Saturday, and the race on Sunday.

If any of these assumptions doesn't fit (for example if your September 10K no longer matches your current fitness, or if you can/want to run more days), let me know and I'll adjust it.

The plan, week by week

Sixteen weeks is a lot to scroll. Every week is folded — open the ones you want, and week one is open already.

15 weeks · Peak week 15 · 61 km planned

Week 1from 12 Oct4 sessions21 km planned

Easy warm-up

  • Wed 14
    Strength
    Back squat 3 × 6 · moderate-heavy · Bulgarian split squat 3 × 8 per side · moderate · Single-leg calf raise (straight knee) 3 × 12 · bodyweight+ · Single-leg calf raise (bent knee) 3 × 12 · bodyweight+ · Single-leg glute bridge 3 × 10 per side · bodyweight
  • Thu 15
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run, feel and conversational pace.
  • Sat 17
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run, same relaxed pace.
  • Sun 18
    Long · 9 km @ 5:45-6:00/km · 45–60 min
    Long run at controlled pace, comfortable from start to finish.
Week 2from 19 Oct5 sessions29 km planned

First quality touch

  • Tue 20
    Tempo run · 8 km · 35–50 min
    Continuous threshold pace, controlled.
  • Wed 21
    Strength
    Back squat 3 × 6 · moderate-heavy · Bulgarian split squat 3 × 8 per side · moderate · Single-leg calf raise (straight knee) 3 × 12 · bodyweight+ · Single-leg calf raise (bent knee) 3 × 12 · bodyweight+ · Single-leg glute bridge 3 × 10 per side · bodyweight
  • Fri 23
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run.
  • Sat 24
    Easy · 5 km @ 5:45-6:00/km · 25–35 min
    Easy run.
  • Sun 25
    Long · 10 km @ 5:45-6:00/km · 50–65 min
    Long run, up 1 km from last week.
Week 3from 26 Oct5 sessions30 km planned

Building volume

  • Tue 27
    Cruise intervals · 3 × (1 km / 400 m) · 35–45 min
    Threshold pace repetitions with short jog recoveries between.
  • Wed 28
    Strength
    Back squat 3 × 6 · moderate-heavy · Bulgarian split squat 3 × 8 per side · moderate · Single-leg calf raise (straight knee) 3 × 12 · bodyweight+ · Single-leg calf raise (bent knee) 3 × 12 · bodyweight+ · Single-leg glute bridge 3 × 10 per side · bodyweight
  • Fri 30
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run.
  • Sat 31
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run.
  • Sun 1
    Long · 11 km @ 5:45-6:00/km · 55–70 min
    Long run, comfortable and controlled.
Week 4from 2 Nov4 sessions18 km planned

Recovery week

  • Tue 3
    Easy · 5 km @ 5:45-6:00/km · 25–35 min
    Easy run, lower volume week.
  • Wed 4
    Strength
    Back squat 3 × 6 · moderate · Bulgarian split squat 2 × 8 per side · moderate · Single-leg calf raise (straight knee) 2 × 12 · bodyweight+ · Single-leg calf raise (bent knee) 2 × 12 · bodyweight+ · Single-leg glute bridge 2 × 10 per side · bodyweight
  • Fri 6
    Easy · 5 km @ 5:45-6:00/km · 25–35 min
    Easy run.
  • Sun 8
    Long · 8 km @ 5:45-6:00/km · 40–55 min
    Short long run, week to recover legs.
Week 5from 9 Nov5 sessions31 km planned

Back to progression

  • Tue 10
    Progressive run · 7 km · 30–40 min
    Progressive: build pace by blocks up to near threshold.
  • Wed 11
    Strength
    Back squat 3 × 5 · heavy · Bulgarian split squat 3 × 8 per side · moderate-heavy · Single-leg calf raise (straight knee) 3 × 12 · bodyweight+ · Single-leg calf raise (bent knee) 3 × 12 · bodyweight+ · Single-leg glute bridge 3 × 10 per side · bodyweight
  • Fri 13
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run.
  • Sat 14
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run.
  • Sun 15
    Long · 12 km @ 5:45-6:00/km · 60–80 min
    Long run, your longest yet.
Week 6from 16 Nov5 sessions32 km planned

Raising the bar

  • Tue 17
    On/offs · 8 × (1 min / 1 min) · 35–45 min
    Short intervals fast/easy to work on speed.
  • Wed 18
    Strength
    Back squat 3 × 5 · heavy · Bulgarian split squat 3 × 8 per side · moderate-heavy · Single-leg calf raise (straight knee) 3 × 12 · bodyweight+ · Single-leg calf raise (bent knee) 3 × 12 · bodyweight+ · Single-leg glute bridge 3 × 10 per side · bodyweight
  • Fri 20
    Easy · 7 km @ 5:45-6:00/km · 35–45 min
    Easy run.
  • Sat 21
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run.
  • Sun 22
    Long · 13 km @ 5:45-6:00/km · 70–85 min
    Long run.
Week 7from 23 Nov5 sessions37 km planned

Building base for the marathon

  • Tue 24
    Tempo · 8 km · 40–50 min
    Continuous threshold.
  • Wed 25
    Strength
  • Fri 27
    Easy · 7 km @ 5:45-6:00/km · 35–45 min
    Easy run.
  • Sat 28
    Easy · 7 km @ 5:45-6:00/km · 35–45 min
    Easy run.
  • Sun 29
    Long · 15 km @ 5:45-6:00/km · 80–100 min
    Long run.
Week 8from 30 Nov4 sessions22 km planned

Recovery week.

  • Tue 1
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run, reducing load.
  • Wed 2
    Strength
  • Fri 4
    Easy · 5 km @ 5:45-6:00/km · 25–35 min
    Easy run.
  • Sun 6
    Long · 11 km @ 5:45-6:00/km · 55–70 min
    Short recovery long run.
Week 9from 7 Dec5 sessions40 km planned

Marathon pace emerging.

  • Tue 8
    Tempo · 9 km · 45–60 min
    Progressive with marathon pace section.
  • Wed 9
    Strength
  • Fri 11
    Easy · 7 km @ 5:45-6:00/km · 35–45 min
    Easy run.
  • Sat 12
    Easy · 7 km @ 5:45-6:00/km · 35–45 min
    Easy run.
  • Sun 13
    Long · 17 km @ 5:45-6:00/km · 90–110 min
    Long run.
Week 10from 14 Dec5 sessions43 km planned

Building volume.

  • Tue 15
    Tempo · 9 km · 45–60 min
    Threshold, longer block.
  • Wed 16
    Strength
  • Fri 18
    Easy · 8 km @ 5:45-6:00/km · 40–55 min
    Easy run.
  • Sat 19
    Easy · 7 km @ 5:45-6:00/km · 35–45 min
    Easy run.
  • Sun 20
    Long · 19 km @ 5:45-6:00/km · 100–125 min
    Long run with final km at marathon pace.
Week 11from 21 Dec5 sessions46 km planned

Peak volume approaching.

  • Tue 22
    Tempo · 10 km · 50–65 min
    Threshold, controlled effort.
  • Wed 23
    Strength
  • Fri 25
    Easy · 8 km @ 5:45-6:00/km · 40–55 min
    Easy run.
  • Sat 26
    Easy · 7 km @ 5:45-6:00/km · 35–45 min
    Easy run.
  • Sun 27
    Long · 21 km @ 5:45-6:00/km · 110–135 min
    Long run.
Week 12from 28 Dec4 sessions27 km planned

Recovery week.

  • Tue 29
    Easy · 7 km @ 5:45-6:00/km · 35–45 min
    Easy run, reducing load.
  • Wed 30
    Strength
  • Fri 1
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run.
  • Sun 3
    Long · 14 km @ 5:45-6:00/km · 75–90 min
    Recovery long run.
Week 13from 4 Jan5 sessions46 km planned

Final long run hard.

  • Tue 5
    Tempo · 9 km · 45–60 min
    Threshold with final section at marathon pace.
  • Wed 6
    Strength
  • Fri 8
    Easy · 8 km @ 5:45-6:00/km · 40–55 min
    Easy run.
  • Sat 9
    Easy · 7 km @ 5:45-6:00/km · 35–45 min
    Easy run.
  • Sun 10
    Long · 22 km @ 5:45-6:00/km · 115–140 min
    Your longest long run, with marathon pace section.
Week 14from 11 Jan5 sessions32 km planned

Taper begins.

  • Tue 12
    Tempo · 7 km · 35–45 min
    Short threshold, reducing volume now.
  • Wed 13
    Strength
  • Fri 15
    Easy · 6 km @ 5:45-6:00/km · 30–40 min
    Easy run.
  • Sat 16
    Easy · 5 km @ 5:45-6:00/km · 25–35 min
    Easy run.
  • Sun 17
    Long · 14 km @ 5:45-6:00/km · 75–90 min
    Short long run, fresh legs.
Week 15from 18 Jan4 sessions61 km planned

Race week

  • Tue 19
    Cruise intervals · 3 × (1 km / 300 m) · 35–45 min
    Sharpening: maintain the pace, very low volume — you should finish wanting to do it again.
  • Thu 21
    Long · 9 km · 45–55 min
    Race rehearsal: easy with a section at marathon pace, race outfit and race breakfast.
  • Sat 23
    Easy · 5 × (25s / 1 min) · 20–30 min
    Activation: very short, with short progressions at race pace.
  • Sun 24
    Race day · 42.2 km @ 5:20/km · 205–245 min
    Marathon! Target 3:45:00, pace 5:20/km.
Other plans
Marathon under 3:00 →Marathon in 3:30 →Marathon in 4:00 →First marathon, 4:30 →5K under 20:00 →5K in 22:00 →5K under 25:00 →5K in 30:00 →10K under 40:00 →10K under 42:00 →10K in 45:00 →10K in 50:00 →10K in 55:00 →Half under 1:30 →Half in 1:45 →Half in 2:00 →Half in 2:10 →Half in 2:15 →First half, 2:30 →First trail, 25K →Trail marathon, 42K →50K trail →

Yours would look different

Tuin writes every plan from the runs it can actually see and the goal you set — then keeps rewriting it as your weeks happen. The whole of it is free for 7 days.

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Marathon training plan for 3:45 · Tuin