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Playbook · 09 · Riders
Racing at ten thousand feet
The altitude is the whole point and the whole difficulty. A rider who is fit at sea level can still come apart on a 13,000-foot pass if they don't plan for the air, the weather and the gearing. Here is what to know before you line up.
The altitude, honestly
Leadville starts at 10,152 feet and the passes climb well past 12,000. There is roughly a third less oxygen than at sea level. Your power at threshold drops, your heart rate runs higher for the same effort, you dehydrate faster in the dry air, and you recover more slowly overnight between stages. None of that is a reason to stay home. It is the reason finishing means something. Plan for it and it becomes the adventure instead of the disaster.
Acclimatize, or don't gamble
There are two workable plans and one bad one.
- Arrive early (best). Come up several days to two-plus weeks ahead and let your body adapt. If you can sleep high before the race, do it.
- Race off the plane (workable). Some riders do better racing within the first 24 hours, before altitude symptoms peak around days 2–3. If you can't arrive early, arrive the day before.
- Arrive two or three days out (worst). That's often when acute mountain sickness hits hardest. Avoid landing squarely in that window.
Pace and effort
Go out at your sea-level power on the first climb and you will pay for it all week. Ride to feel and heart rate, keep something in reserve on the early passes, and remember this is a stage race: the overall rewards the rider who is still strong on the last day, not the one who won stage one and blew up.
The bike
- Gearing. Go easier than you think. Long, high grinds on loose surfaces reward a wide-range cassette and a small chainring. A gravel bike with a mullet or 1x setup and a big cassette, or a lightweight hardtail, both work.
- Tires. Tubeless, with sealant, and a tread that handles loose rock and washboard. Bring a proven setup; don't experiment race week. Carry the tools and plugs to fix a flat yourself between aid stations.
- Pressure. Lower than road, tuned to your weight and the surface, but not so low you rim-strike on the rocky descents.
- Prep. Fresh drivetrain, brakes and sealant before you travel. A mechanical on a remote pass is a long day.
Fuel and water
Eat and drink more than at sea level and start before you feel you need to. The dry air hides how much fluid you're losing. Balance water with electrolytes to avoid over-drinking plain water on the long days. Practice your race nutrition in training so nothing is new on the mountain.
What to carry
- A real jacket and layers. It can snow in July up high. A packable shell and warmth for a cold, exposed descent are non-negotiable, and will be on the mandatory-kit list.
- Repair kit — tube, plugs, pump/CO2, multitool, chain link.
- Sun protection — the UV at altitude is fierce; sunscreen, lip balm, eye protection.
- Your phone and any required tracker, though don't count on cell coverage on the passes.
Sources
- Wilderness Medical Society and CDC high-altitude guidance
- Established high-altitude race athlete guides (Leadville Race Series)
- Your own coach and physician for anything medical