Empower Field at Mile High in Denver, Colorado is the most physically demanding venue on the supercross calendar for one simple reason: altitude. At 5,280 feet above sea level — exactly one mile high — the thinner air affects both machinery and the human body in ways that teams spend significant resources preparing for.
The Altitude Factor
At 5,280 feet, atmospheric pressure is roughly 17% lower than at sea level. For naturally aspirated motorcycle engines, this means less oxygen in each combustion cycle and a corresponding reduction in horsepower. Teams re-jet or adjust fuel injection mappings specifically for Denver — a poorly tuned bike at altitude feels sluggish and unresponsive.
For the riders themselves, altitude means reduced oxygen availability during what is already an extremely demanding physical activity. Riders who have trained at altitude or arrived several days early to acclimatize have a measurable advantage. By the final laps of a 20-lap main, the difference in cardiovascular conditioning becomes visible.
"Denver is where fitness and preparation separate the field more than raw speed. You can outride someone all season and still lose to them at altitude."
— Moto, Moto Track GuideChampionship Implications
Round 16 of 17 means Denver is the penultimate round of the season. By the time the gate drops at Empower Field, the championship picture is almost always clear. Denver's unique conditions add unpredictability to that final calculation — a rider who has dominated all season can have an uncharacteristically difficult night at altitude, while someone who has struggled can find their best ride of the year.