The Field Notes
Course guides & training science.
What the world's hardest races actually demand — and how to train for the terrain, not just the distance.
The WAI2K 25km Quad Extender: The Real Race Starts After You Think You're Done
Most of the WAI2K 25km's climbing is saved for a 600m [1,970 ft] out-and-back up Mt Climie at the very end. Pace it like a flat loop and you'll pay for it late.
Adam Allen · 26 Aug 2026 · 3 min readThe WAI2K 50km Front-Loads Its Climbing — Here's Why That's a Trap
WAI2K packs most of its 2,600 m [8,530 ft] of vert into the first half. That doesn't mean the back half is easy — it means the bill for the climb comes due later, on tired legs.
21 Aug 2026 · 4 minCourse GuideWAI2K 100km Saves Its Last Climb for the Dark
The WAI2K 100km shares its first 43 km with the 50km, then saves a genuine climb — Mt Climie — for the final 14 km, likely in the dark.
10 Aug 2026 · 5 minTrainingDurability Isn't a Side Effect of Fitness
A big aerobic engine doesn't guarantee you won't fade late — durability is a separate quality, and it's built differently.
3 Aug 2026 · 2 minCourse GuideWhat the Mammoth 50K Actually Asks of You
A high-altitude 50K that tests four separate capacities in one day — here's what the whole Mammoth course actually asks of you.
27 Jul 2026 · 4 minCourse GuideWhy "More Elevation" Doesn't Mean "Harder
Two very different New Zealand ultras, two very different failure modes — why comparing them by distance or vert alone misses the point.
18 Jul 2026 · 4 minWestern StatesGolden Ticket Season: Three Races, Three Completely Different Demands
Course Guide description: CCC, Javelina Jundred, and Tarawera 102K all punch a ticket to Western States, but they ask almost opposite things of your legs.
10 Jul 2026 · 4 minCourse GuideWhere Runners Fall Apart at Tarawera: The Three Failure Modes of the T102
Most runners don't blow up at Tarawera on a climb — the T102 doesn't have one. They come undone in the back third. Here are the three failure modes, and how to train for each.
6 Jul 2026 · 5 min