A butt-kicking Ski Boot Camp Saturday. The weather may not be ready for ski season, but you can be by attending a free exercise class designed to tone and strengthen those shredding muscles. Hosted by Christy Sports and Arapahoe Basin Ski Area, the event includes an hour-long high-intensity interval training (HIIT) workout, plus gear tuning, music, mingling and refreshments — all for free. Bring a yoga mat, your skis or snowboard, and thoughts of powder days.