There are plenty of retreats dedicated to getting you in shape, but this spa's location in the middle of Utah's spectacular red-rock country--with its virtually unlimited outdoor activities--nudged it past its peers. Check in and create your own personalized mix of fitness and adventure. Choose from more than 50 exercise classes every week, plus hiking, rock climbing, kayaking, and mountain biking. Staff pros assess fitness, dietary, lifestyle, and metabolic rate to help you take your newfound health habits home. Top all that with a pampering treatment in the new Sagestone Spa, which boasts stunning views.

Book it: From $239 per person per night; 800-407-3002;