Ultimate Bootcamp, Woburn

Cofounders Jill Tomich and Peter Lavelle had both been active in the fitness world before they opened Ultimate Bootcamp in 2004. Jill threw her energies into boxing, ballet, yoga, and blogging for a wedding diet-and-fitness website, and Peter, a native Irishman, was a triathlete. In all his pursuits, Peter adhered to the motto "We're not here for a long time—we're here for a good time."

This credo infuses all of the boot-camp programs. Campers from all across the fitness spectrum find accommodation as the workouts meet them close to home. Trainers never push too far, but always challenge. An energetic mix of outdoor-resistance and interval training layers patrons in svelte muscle, builds strength, and burns calories to promote weight loss more effectively than a rice cake's PR agent. Far from the stereotypical idea of a boot camp, encouragement and support roll in from instructors who foster cooperation and camaraderie between fellow boot campers.