Ultra 100K – Intensity First
Magic Training
About the plan
Twenty weeks for a 100K ultramarathon (62 miles), organized around the principle Jason Koop popularized in ultra training: intensity first, specificity later. Instead of starting with long runs, the plan spends the first twelve weeks building the engine: four weeks of aerobic base with strides, four of VO2 max and hills, and four of threshold in 10-minute blocks and continuous tempo runs, with the Sunday long run growing in parallel from 15 to 24 miles (24 to 38 km). Only then come the six specific weeks, when training starts to look like the race: steady running at marathon pace on Tuesday, back-to-back long run weekends (Saturday and Sunday), and long runs with planned walking blocks, because in a 100K, walking well is part of the strategy. The high point is the 30-mile (49 km) simulation in week seventeen, with two 30-minute walking blocks; after it comes a three-week taper into race day. Volume runs from 39 to 73 miles (63 to 117 km) per week, with a cutback every four weeks, and each walking block is written as walk so your watch marks the transition. For runners who have already completed at least one marathon or a 50K and want to reach the 100K with a plan that trains pace and mindset, not just mileage.
The plan in numbers
- Duration
- 20 weeks
- Runs per week
- 6
- Weekly volume
- 43 mi · 8 min → 71 mi · 30 min
- Longest run
- 27 mi · 1h
Week 1 starts at 43 mi · 8 min and volume builds to 71 mi · 30 min in week 15, the heaviest of the plan.
A typical week has 6 runs, and the longest session reaches 27 mi · 1h (Long, week 17).
Over the final 5 weeks volume drops from 71 mi · 30 min to 12 mi · 8 min so you arrive at the race rested.
Race day (62 mi) falls on Sunday of week 20; the week holds 12 mi · 8 min of running before it.
Key workouts
The quality sessions that come up most in this plan:
- Long24 sessions across 19 weeks
- Interval8 sessions across 4 weeks
- Threshold8 sessions across 4 weeks
- Marathon7 sessions across 7 weeks
Who it's for
Advanced level. To start safely you should already be running about 43 mi · 8 min per week and be comfortable with a 15 mi session — that is what week 1 asks for.
Week 1 — workout preview
43 mi · 8 min this week
6.2 mi · 8 min
7.5 mi
8.7 mi
6.2 mi
15 mi
Week 15 — the heaviest of the plan
71 mi · 30 min this week
12 mi
7.5 mi
9.9 mi
5 mi
16 mi
21 mi · 30 min
Plan Structure
20 weeks · 114 workouts · 26 rest days
See the full plan
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