V3 Outdoor Fitness, Boulder

Whether she's racing her dogs on one of Boulder's scenic trails or leading boot-camp classes, V3 Outdoor Fitness's founder, Samantha Watts, is always in motion. Though her favorite sport is running, the personal-fitness trainer incorporates a bevy of total-body toning moves into her outdoor boot-camp classes. Push-ups, squats, weight training, stair climbing, and sprints torch calories and tighten abdomens during one-hour sessions held at North Boulder Park. The varying exercises give certain muscle groups a break while working others to more efficiently fill out roomy T-shirt sleeves and render foam muscle suits unnecessary. Sam also offers a trail running program to help fellow rustic hoofers hone their speed and endurance.