Skip to content

The Air Up Here: How to Prepare to Race at Altitude

10,200 feet. That’s the starting altitude of the Leadville Race Series. It’s dizzying just to think about. And whether you’re riding the Leadville Trail 100 MTB or running the Leadville Trail 100 Run—or competing in any other events in the Leadville series—you’re going to notice the barely-there air.

At elevation, your red blood cells struggle to move oxygen through your body, leaving your muscles starving for air and adding to the struggle of an already tough event. Additional side effects of altitude include dehydration, headache, lethargy, nausea, difficulty sleeping and lack of appetite—hardly ideal conditions for race day. But fear not, Leadville athletes! With proper preparation, a smart strategy and a healthy attitude, you’ll be ready to tame the thin-aired Leadville beast that lurks high in the Rocky Mountains—and earn bragging rights to last a lifetime.


Let’s face it. Most of us don’t live above tree line. Even high altitude training strongholds like Boulder, CO and Ketchum, ID are just shy of 6,000 feet—which, in lung-suck speak, doesn’t come close to Leadville’s 10,200-foot base. And the Leadville course continues up, and up, and up…and up! (The LT100 MTB tops out at 12,424 feet; the LT100 Run peaks at 12,600 feet.)

Theories about acclimatization abound, but unfortunately, there is no shortcut. The ideal way to prepare to perform at elevation is to slowly and steadily move into thin air, allowing your body to adjust at progressively higher elevations. The rule of thumb is that it takes nearly three weeks for your body to adjust about 90 percent to a high altitude environment; it takes a full six weeks to be 100 percent acclimatized.

Heading to a race venue six weeks in advance is hardly realistic. But any advance preparation is beneficial—both to get to know the course and to get a feel for the high altitude environment. If possible, plan a vacation in the mountains earlier in the summer. Cyclists can still register for the 2017 Leadville Trail 100 MTB Camp (June 29-July 1) or tackle the Silver Rush 50 MTB (July 8). You can also explore the race course on your own, or with family and fellow athlete friends.

It’s also advisable to head high (9,000 feet or higher) a full two weeks before the race. Again, this isn’t an option for every athlete, but if possible, go. Your body will begin to acclimate and build more oxygen carrying red blood cells, and added familiarity with the course and conditions will help calm pre-race nerves.


If your only option is to arrive in Leadville a day before the race, don’t stress. Even a lifetime lowlander seeking the ultimate 100-mile challenge can have a successful race—and you certainly won’t be alone. Every year, the list of Leadville entrants is chock-full of people from elevation-challenged states. Your best bet is to arrive as fit and healthy as possible. A fit, powerful, well-rested and injury-free athlete with a strong cardiovascular system is going to have a leg up on altitude from the second the gun goes off. Altitude affects everyone differently—some people much more harshly than others—but you’ll stand the greatest chance of success by arriving in Leadville in top physical form.

When you reach high altitude, you may notice your heart racing and your breathing rate increasing. This is normal—your heart and lungs are working harder for the body to get the oxygen it needs. You may also have trouble sleeping, a common problem for anyone traveling up high. Do your best to get plenty of rest, and be sure to hydrate and keep a healthy electrolyte balance. And remember, leave your stress at home. Try not to worry about the altitude. The challenging conditions can’t be changed, but a calm approach is one factor you can control.

 “L” DAY

On race day in Leadville, you’ll want to pay equal attention to your physical and mental states. A steady effort and self-monitoring throughout the race will surely reap greater rewards than an all-out push. Here’s how to best battle the effects of altitude on body and mind during the race:

  • If a day-before arrival is your strategy, smarts are your ticket to success. Understand that your body is working harder to get oxygen, so help it along by starting the race a little slower and riding or running on perceived exertion instead of the numbers on your heart rate monitor or power meter.
  • Pay special attention to nutrition. Be proactive with fueling. Once you get behind, it’s very difficult to catch up and recover. Depending on body size and pace, you should aim for about 60 grams of carbohydrates per hour.
  • Hydrate—with electrolyte replacement drink—the whole way. With inadequate rehydration, athletes can experience dangerous increases in body temperature and cardiac strain. Additionally, research has shown that athletes competing in the Leadville 100-mile races lose significant amounts of sodium. Consider adding salt to your sports drinks and consuming salted foods like pretzels or soup.
  • Upset stomachs happen. In the event of tummy trouble, give yourself smaller nutritional goals. Take little sips of water or electrolyte drink along with small amounts of food, with whatever frequency you’re able.
  • Chances are, at some point, the effects of racing at over 10,000 feet will kick in. You may feel dizzy, extremely fatigued, foggy or nauseated. You may even throw up. Don’t panic—it’s just part of the challenge.
  • Know that rough patches come and go—and can often be overcome. Keep your cool and know that this is to be expected. Try to embrace a positive attitude and draw energy from the beautiful scenery. Keep your mind set on reaching the next aid station where you can take a short break, refuel, get a good charge from family or friends or pick up your pacer.
  • Throughout the race, constantly reassess how you are feeling and make adjustments on the fly. If you can maintain a sharp enough mind to continually self-monitor and stay on top of your hydration and nutrition, then no matter your pace, you’ll be a strong contender to reach the finish!

Want to learn more about the physiological effects of altitude?

Competing At Altitude

Back To Top