Biking at Altitude—Is a Mile High Really a Big Deal?

You're training for the CommonSpirit Denver Century Ride—logging the miles, climbing the hills, feeling confident. Then it hits you: I don’t live at altitude.

You can train for just about everything… but you can’t simulate riding a bike at 5,280 feet above sea level. So, how big of a deal is it?

Will You Get Altitude Sickness in Denver?

True altitude sickness typically kicks in above 8,000 feet, so severe conditions like high-altitude pulmonary edema aren’t a concern in Denver. But that doesn’t mean you won’t feel anything.

Even at a mile high, it’s common for riders to experience:

• Headaches
• Fatigue
• Muscle cramping
• Shortness of breath
• A frustrating sense that you're suddenly out of shape

It’s not in your head—it’s in your lungs. There’s simply less oxygen in the air here, and your body needs time to adjust.

What Can You Do to Prepare?

✅ Arrive Early If You Can
If you are coming in from out of state, fly in 2–3 days before the ride. Even earlier is better. While full acclimation takes longer, those extra days will help your body start to adapt.

✅ Hydrate, Hydrate, Hydrate
Yes, I’ve said it before—but it’s worth repeating. Dehydration puts extra stress on your system and mimics altitude symptoms. Stay ahead of it by drinking plenty of fluids before, during, and after your travel.

✅ Hold Off on the Local Brews
Denver’s craft beer scene is tempting, but alcohol can worsen the effects of altitude. If you must indulge before race day, do so lightly—and chase every drink with water.

✅ Prioritize Rest
Sleep is your superpower. Giving your body the downtime it needs before the race helps reduce physiological stress and makes the altitude feel more manageable on ride day.

The bottom line: altitude won’t ruin your ride—but ignoring it might. Plan ahead, give your body the tools it needs, and save the beer for the post-ride celebration. Your lungs will thank you.