Leadville Trail 100 training: a hundred miles that never drops below 9,000 feet

Leadville is an out-and-back hundred from the highest incorporated city in the United States, starting at four in the morning at 10,200 feet and never dropping below 9,200. The middle of the race crosses Hope Pass, 12,526 feet, twice: out to the turnaround at Winfield and back. The limit is 30 hours; under 25 earns the big buckle. In 2026, on a course rerouted for a wildfire, about six in ten starters finished. On the normal course it is often fewer.

The climbing is modest for a mountain hundred. The altitude is not. Leadville is the race that punishes runners who confuse the two.

The whole race is above 9,000 feet

At 10,000 feet a sea-level runner has around a third less oxygen available per breath, and the effect does not wait for the climbs: easy pace on the runnable shoreline miles around Turquoise Lake costs more heart rate than it should, and the runner who holds their British easy pace there arrives at Twin Lakes already in debt. Then Hope Pass. The organisers write, in capitals, that you should not attempt the round trip to Hope Pass without warm and protective clothing, and they list lightning above the timberline and hypothermia as the hazards that kill. Two weeks at altitude before the race is the preparation that matters most, and the plan treats it as part of the race cost. Where that is impossible, the first 40 miles are run at a heart rate, not a pace, and the cap is set for 10,000 feet.

Hope Pass, twice

From Twin Lakes it is around 3,400 feet up to the pass on the way out, a descent to Winfield, and then the same climb again from the steeper side with 50 miles in your legs. Everybody walks it. The runner who walks it well, at a cadence they can hold for an hour with breathing they could talk through, is the runner who gets back to Twin Lakes before the cut-off. The walking note is the training for this; the descents into Winfield and back to Twin Lakes are where the quads pay, and the winter strength work is what protects them.

Cold, wet feet, night

August in Leadville can bring rain, hail and snow on the same afternoon, and nights in the upper 20s Fahrenheit, below freezing, after 20 hours awake. Lake Creek is crossed twice, so feet are wet twice, and the foot-care and shoe-change plan is rehearsed with crew at Twin Lakes. The second night, on the Powerline climb and around the lake, is where the night note earns its place: layers on before the cold arrives, food by the clock when appetite has gone, and a pacer who has been briefed.

Where durability shows up

Leadville has long runnable stretches, so the watch data is cleaner than most mountain hundreds and the durability reads are good: late-run pace at the easy cap on long runs against the first hour, and how much the big hikes cost once the legs are tired. Through an altitude fortnight, heart rate at easy effort tells me acclimation is taking. The pattern I am looking for is the same as always: engine intact, legs and gut no longer delivering. Then I decide what the next block holds.

The build

The lottery is unweighted and drawn in December. A winter of capped easy volume and two strength sessions; a spring of long runs with a sustained hike in the middle of them, back-to-back weekends, and descents progressed; a fuelling plan that survives cold and altitude, where appetite drops; then, if the calendar allows it, two weeks high before the race, which is the taper. Heat is rarely the problem here. Discipline in the first 40 miles is.

What I watch

• Easy-pace heart rate on runnable long runs, and the discipline to hold it when the pace feels slow.
• Uphill walking speed at the easy cap on long climbs, over the build.
• Late-run pace on long runs against the first hour.
• Easy-effort heart rate through the altitude fortnight.
• Fuelling in the cold and at altitude, where appetite goes first.
• Recovery after back-to-back weekends, where masters legs get caught.

Facts checked September 2026 against leadvilleraceseries.com: 99.7 miles out and back, start at 10,200 ft, 15,492 ft of gain, Hope Pass at 12,526 ft crossed twice, a low point of 9,206 ft, a 04:00 start and 30-hour limit with the cut-offs above, pacers from Twin Lakes inbound, crew at designated stations only, an unweighted December lottery and a $495 fee in 2026. The organiser's own page gives the Winfield turnaround as both 49.8 and 52.2 miles. The 2026 course was rerouted for the Willow Fire, so its finish rate of about 59% comes from results listings and is not comparable to the traditional route; the 2027 date had not been announced when this was checked. Evidence level: the altitude and pacing physiology matches the field notes; the course demands are the race's own.