The altitude is one of the most demanding features of Ride the Rockies. Research suggests that aerobic capacity decreases by about 2 percent for every 1,000 feet of elevation gained. According to Joe Friel, author of The Cyclist’s Training Bible, it would take around four weeks to acclimatize for this ride, so showing up early probably isn’t an option. His advice for sea-level dwellers? “Just get in the best aerobic condition you can wherever you live,” he says. “That will translate to better performance up high.” To do that, make sure you follow the training plan, paying particular attention to the high-intensity sprints and hill climbs. Doing so won’t save you from getting taken down a notch or two by Colorado’s thin air, but you’ll be a few notches higher to start with.