Guest Blog: Ian Sharman
The Leadville Trail 100 Mile (“LT100”), aka “The Race Across The Sky,” is one of the most iconic and long-standing ultras in the world. Started in 1983 with the idea to revive a dying mountain town high up in the Colorado Rockies, it’s attracted many of the sport’s biggest names and is the largest 100-miler in the US by entry numbers. Although the terrain is tough, the defining factor of this race is the high altitude, with Leadville town itself at 10,200ft. The high point of the course is on Hope Pass at 12,600 ft, which runners traverse twice due to the 50-mile out-and-back format of the race.
There’s a lot of advice available about how to train for ultras in general, but not so much about training for the altitude element. The history, lack of a lottery and zero qualifying criteria for LT100 mean there’s a lot of sea level-dwelling athletes wanting to run but having second thoughts due to the thin air. So here are some tips for how to approach training for LT100 itself for the majority of us who don’t live high in the mountains. These also widely apply to other high altitude events, especially those with significant sections above about 8,000 ft, where Acute Mountain Sickness becomes a risk.
1. Plan to run a lot – sounds obvious, but LT100 is a very runnable course for the most part with long stretches of flat or near-flat running, despite it being high in the mountains. Switching between hiking on climbs and running the flats is a very effective tactic which allows the leg muscles regular rests from the impact of running. The legs then feel fresher to restart running when the terrain gets easier again.
2. Don’t arrive a few days before the race – ideally spend well over one week in Colorado above 6,000 ft. I’d recommend two weeks as a good minimum to start to see significant benefits from altitude acclimatization (mainly the production of more red blood cells to transport more oxygen to the muscles). The worst thing you can do is arrive between about two and six days before the race coming from sea level. Research (such as that summarized in The Lore of Running by Professor Tim Noakes) shows that arriving into a high altitude location for this amount of time pre-race means you feel the negative side-effects of being at altitude without noticeable positive adaptations. It’s more effective to arrive the afternoon before the race, pick up your race number and then run the race before the altitude has time to affect you as much, but I wouldn’t advise that either. Ultimately, entering a race like this requires a commitment to go out to the race with enough time to acclimatize, so consider that before entering. Around 50% of the field doesn’t finish and lack of altitude adaption is a large factor in such a high rate.
3. Hike above the high point of the race – if you can make more of a vacation of the race then relaxed hiking some of Colorado’s “fourteeners“ (Colorado has 58 mountain peaks exceeding 14,000 feet – known as “fourteeners” or “14ers” locally) is a great way to spend time pre-race, but not the last few days. It helps your body adjust to the altitude faster, strengthens your ability to hike and gives spectacular views without being too strenuous.
4. Consider using an altitude tent – these can be rented and attach over your bed, allowing you to sleep with air that’s more similar to what you experience at high altitude, although it doesn’t replicate the pressure differential. Downsides are the cost, heat/humidity inside the tent and the fact your other half may consider your ‘hobby’ to be too weird and ban you from doing any more races. If possible, going to altitude is more effective, but time off work and a family vacation for two weeks in the mountains is a big commitment, too.
5. Take it extra easy in the race – aim to keep your intensity low so your oxygen needs are also relatively low. It’s easy to get caught up in the excitement and try to run lots of the climbs because they’d be runnable at sea level. Running at two miles above sea level makes a big difference and the oxygen content in the air is almost exactly one third less than at sea level. That increases to a 38% oxygen reduction at 12,600 ft (based on calculations from here). So if you can keep your effort level down you’re less likely to feel the early symptoms of altitude sickness, such as throbbing headaches. In particular, go especially gently on the two ascents of Hope Pass.
6. Eat regularly from early on – whatever your normal eating strategies in races, stick to it with more discipline in the early stages of LT100. Once you feel symptoms of altitude sickness (which you probably will to some degree within the race) it’ll be especially hard to stomach anything and keep up your energy reserves.
7. Hope Pass is the key – if you treat the race as starting after your second descent of Hope Pass at around mile 58, then it’ll focus your mind and your tactics well. Aim to get to this point feeling as good as you can and not getting caught up in mini races against people before that or trying to hit splits for particular finish times (like the sub 25-hr buckle). Run based on how you feel and concentrate 100% on looking after yourself to avoid serious issues for as long as possible.
Good luck to everyone since it’s a classic event and a must-do race for ultrarunners.
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These are all very worthwhile points of advice. But for many runners, we do not have the opportunity to spend a few idle weeks in Colorado before the race, running up hills and doing stuff to keep the nervous energy at bay. I personally think that altitude tents and other devices is a bit like cheating. Either do it properly or not at all. Turn up, run the race, go home. Trail running an ultra is a raw and pure activity that strips everyone down to bare basics and should remain that way, without fancy devices to ease the pain. Leadville is always about altitude and either you can put up with it or not. That said, for a genuine first timer looking to do one ultra and one only, this advice is pretty good.