Mount Blue Sky Hill Climb: Training Guide

Train sustained power, not sprints

Blue Sky is a long, steady climb, so the fitness that matters is your threshold and sub-threshold power and your ability to hold it for hours. Build your program around extended efforts: sweet-spot intervals (88-94% of FTP) progressing from 2x20 minutes toward 2x30 or 3x20, plus full threshold blocks at 95-105% of FTP. Long climbs in your own terrain, ridden at a controlled tempo, are the most specific and most valuable sessions you can do.

Because the effort is so long and so steady, also train your fatigue resistance. Do over-unders (alternating just above and just below threshold) to teach your body to clear lactate while still working hard, and finish some long endurance rides with a 20-30 minute climbing tempo block so you are practicing the back half of the climb on already-tired legs. There is no benefit to anaerobic power here — every watt should go toward raising and durabilizing your steady ceiling.

Respect the altitude — and prepare for it

Above roughly 8,000 feet, your sustainable power starts to drop, and by the 14,000-foot finish the effect is severe. There are two practical ways to blunt it. The first is to arrive and acclimatize: spending a week or more at altitude before the event lets your body begin adapting. The second, if you live at low elevation, is the opposite — arrive as late as possible, race before acute mountain sickness sets in, then leave. The worst window is two to four days after arrival, when symptoms peak and adaptation has barely begun.

Whatever you choose, pace the upper mountain by feel and breathing, not by the power numbers that worked at home — those numbers are simply unavailable up high, and chasing them guarantees a blow-up. Hydrate aggressively, since the dry, thin air dehydrates you faster than you notice, and keep fueling steadily; digestion is harder at altitude, so favor easily absorbed carbohydrate drinks and gels over solid food once you are above treeline.

Pace from the bottom and gear low

The temptation on a hill climb is to attack the lower, lower-altitude slopes where you feel strong. Don't. The climb gets harder as it goes — both because you are tiring and because the air keeps thinning — so the only sustainable strategy is to start conservatively and aim to feel, if anything, slightly under-cooked through the lower forested miles. Riders who go out hard near Idaho Springs routinely come apart above treeline.

Gearing matters more than you might expect on a climb that is not especially steep, because the altitude effectively makes every grade feel steeper than its number. Most riders want a compact or sub-compact crankset and a wide-range cassette so they can keep a comfortable cadence at low power without grinding. Spinning a slightly easier gear protects your legs and helps you breathe in a rhythm — both of which matter enormously over two-plus hours of continuous climbing.

Dress for two seasons

You may start in mild, sunny conditions near 7,500 feet and finish in wind, cold, and the genuine possibility of snow above 14,000 feet. The race typically offers a way to send warm clothing to the summit and to retrieve it for the descent, but you should confirm the current arrangements on the official event site. Plan for a packable jacket, full-finger gloves, and a warm layer for the top and the long descent back down.

The descent itself is long, cold, and fast, and you will be doing it with tired legs and chilled muscles after a maximal effort. Practice descending long mountain roads in training so you are comfortable and safe on the way down. And do at least one or two hard rides in cold, exposed conditions beforehand so your clothing choices and your tolerance for the cold are both tested before race day rather than discovered on it.

Common questions