What 16 Weeks of London Marathon Training Really Looks Like
- Darren Last
- 1 day ago
- 5 min read
Back again… it’s London Marathon Eve. I am waiting patiently… or not so patiently, as the excitement is building.
As ever, the day before a marathon you end up at your wits’ end, killing time. So what better to do than throw your training data into ChatGPT and let AI decide how ready you are, and what 16 weeks of London Marathon training really looks like.
It’s been a great training block, starting in the dark, wintry cold, snow and ice of January and February, through to the rain, wind (and the occasional bit of sun) of March and April.
Fact is, I know I am ready. The training has gone to plan, I’ve added consistent strength and conditioning each week, and I’ve looked after myself with better sleep and nutrition. I’ve been—and remain—injury free, and I’m raring to go.
However… we all love a bit of data. And this fills some time.
So here we have it……
Weeks 1–4 Build → Establish routine and base
Weekly mileage & long runs
Week 1: 61.8 km (Long run: 16.0 km)
Week 2: 53.1 km (Long run: 18.1 km)
Week 3: 73.0 km (Long run: 20.0 km)
Week 4: 81.9 km (Long run: 25.2 km)
Overview
Gradual mileage progression from 61 → 82 km without spikes.
Long run extended steadily from 16 km to 25 km, building time on feet.
Consistency established early with 5–6 run days per week.
Run types included:
Easy runs forming the aerobic base
Steady efforts beginning to introduce load
Light interval sessions reintroduced
Early structure without intensity overload
Fatigue remained low and manageable — strong adaptation phase.
Weekly structure (running only)
Week | Mon | Tue | Wed | Thu | Fri | Sat | Sun |
1 | 7.0 km | 8.3 km | Rest | 9.6 km | 10.0 km | 11.0 km | 16.0 km |
2 | 8.0 km | 7.5 km | Rest | 6.0 km | 10.5 km | 3.0 km | 18.1 km |
3 | 8.0 km | 9.5 km | 10.0 km | 14.5 km | 8.0 km | 3.0 km | 20.0 km |
4 | 9.3 km | 8.6 km | 10.5 km | 11.5 km | 4.1 km | 6.1 km | 25.2 km |
Block summary
Stable and controlled mileage progression
Long run foundation established
Introduction of structure without excessive intensity
Consistency embedded early
What it means
You built durability and routine — the platform everything else depended on.
Weeks 5–8 Increase → Push volume and introduce race effort
Weekly mileage & long runs
Week 5: 93.1 km (Long run: 26.0 km)
Week 6: 67.1 km (🏁 Half Marathon: 21.2 km)
Week 7: 94.6 km (Long run: 30.1 km)
Week 8: 96.3 km (Long run: 33.0 km)
Overview
Volume stepped up into consistent 90 km weeks.
Long runs crossed into true marathon territory (26 → 30 → 33 km).
Training became more structured and specific:
Tempo sessions introduced and extended
Intervals / speed work maintained weekly
High volume of easy runs supporting recovery
Long runs began incorporating steady / marathon effort pacing
Half marathon used as a controlled effort benchmark.
Cutback week absorbed load without disrupting progression.
Weekly structure (running only)
Week | Mon | Tue | Wed | Thu | Fri | Sat | Sun |
5 | 13.2 km | 11.5 km | 12.2 km | 10.5 km | 11.0 km | 8.0 km | 26.0 km |
6 | 12.5 km | 8.5 km | 8.5 km | 10.2 km | 3.0 km | 2.3 km | 🏁21.2 km |
7 | 12.2 km | 9.0 km | 10.5 km | 11.0 km | 12.2 km | 3.0 km | 30.1 km |
8 | 12.2 km | 9.8 km | 7.7 km | 10.7 km | 9.0 km | 7.7 km | 33.0 km |
Block summary
Sustained high mileage achieved
Long-run distance extended significantly
Structured sessions layered effectively
Aerobic capacity improved under load
What it means
This is where you became marathon-ready — not just fit, but capable of the distance.
Weeks 9–12 Peak → Big mileage, big long runs
Weekly mileage & long runs
Week 9: 79.3 km (🏁 Half Marathon: 21.2 km)
Week 10: 87.1 km (Long run: 32.0 km)
Week 11: 100.3 km (Long run: 36.1 km)
Week 12: 100.4 km (Long run: 38.6 km)
Overview
Back-to-back 100 km weeks marked the peak of training.
Long runs extended to 32 km, 36 km, and 38.6 km — full endurance exposure.
Training balance at its strongest:
Consistent interval sessions maintaining speed
Strong tempo efforts supporting sustained pace
High volume of easy runs enabling recovery
Long runs executed at controlled aerobic effort
Heart rate stability across long runs indicates strong aerobic conditioning.
Race week used strategically without compromising peak build.
Weekly structure (running only)
Week | Mon | Tue | Wed | Thu | Fri | Sat | Sun |
9 | 10.0 km | 9.5 km | 14.5 km | 8.0 km | 5.0 km | 3.0 km | 21.2 km |
10 | 12.2 km | 9.0 km | 7.2 km | 10.5 km | 11.3 km | 11.0 km | 32.0 km |
11 | 12.2 km | 9.0 km | 7.2 km | 10.5 km | 11.0 km | 14.0 km | 36.1 km |
12 | 14.0 km | 12.0 km | 7.0 km | 26.1 km | 7.0 km | 12.0 km | 38.6 km |
Block summary
Maximum endurance capacity achieved
Longest runs executed under control
No breakdown despite peak load
Strongest indicator of race readiness
What it means
You proved you could handle the marathon — physically and aerobically.
Weeks 13–16 Freshen up, don’t panic
Weekly mileage & long runs
Week 13: 100.7 km (Long run: 32.1 km)
Week 14: 82.0 km (Long run: 26.1 km)
Week 15: 51.3 km (Long run: 17.0 km)
Week 16: 🏁 Marathon Week
Overview
Final major long run (32.1 km) positioned perfectly.
Smooth transition from high volume to marathon-specific efforts.
Run types shifted to support freshness:
Reduced interval volume
Short tempo efforts maintained
Increased proportion of easy runs
Minimal load in final week
Progressive reduction in mileage (100 → 82 → 51 km).
Fatigue melted away without losing sharpness — ideal taper execution.
Weekly structure (running only)
Week | Mon | Tue | Wed | Thu | Fri | Sat | Sun |
13 | 12.2 km | 9.9 km | 6.0 km | 11.0 km | 10.5 km | 11.6 km | 32.1 km |
14 | 14.0 km | 12.0 km | 7.0 km | 26.1 km | 7.0 km | 12.0 km | 6.5 km |
15 | 7.5 km | 8.0 km | 6.5 km | Rest | 8.0 km | 4.0 km | 17.0 km |
16 | 6.0 km | Rest | 7.0km | Rest | 5km | Walk | Marathon |
Block summary
Fatigue reduced without losing conditioning
Intensity maintained at lower volume
No taper disruption
Athlete arrived fresh and ready
What it means
The taper didn’t just rest you — it unlocked the fitness you’d built.
Overall Trends Summary (Coach View)
This block shows:
High consistency in early morning training discipline, with most key sessions completed between 05:00–08:00
Strong balance of easy runs, long runs, tempo efforts, and interval sessions, building both endurance and speed
Ability to train in real-world conditions — cold mornings, wind exposure, and varied terrain
A clear and repeatable weekly rhythm, anchored by the long run and supported by midweek quality
Progressive improvement in aerobic efficiency, with heart rate stabilising as mileage increased
Smart and well-timed race integration, using half marathons as training tools rather than disruptions
Consistent load management with no major drop-offs, missed phases, or overtraining signal.
Final Conclusions
This training block shows:
Progressive build without spikes
Strong balance of volume and intensity
Excellent long-run execution
Well-timed races
Controlled and effective taper
Readiness
You arrived at London with:
Proven endurance
Stable pacing ability
Strong aerobic conditioning
Managed fatigue
Final line
Nothing about this block was accidental — it was built, week by week, until all that was left to do… was trust it on the start line.
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