If the name Basic Training conjures images of military-style boot camp, it's time to reset your understanding of the word "basic." Basic Training's group fitness classes focus on the most essential elements of exercise, helping you get back to basics while at the same time breaking the monotony of your exercise routine. These classes are challenging in a good way, and if you're a fan of Pilates, running, or yoga, you'll find it's nothing you can't handle. "If you can make it through a 90-minute yoga class, you can totally make it through one of our classes," says founder Jennifer Pattee. "It's also really fun." When she started Basic Training, Pattee set out to banish the scary connotations people often associate with boot camps, so the Basic trainers make every session entertaining and unintimidating. First, you're matched up with a buddy who has a similar skill level and led through a dynamic warmup. Then the focus shifts to strength and endurance, with a mix of cardio, Pilates, ab work, and yoga that engages every muscle group and changes from day to day to keep things interesting. With no more than six clients per trainer, you'll get plenty of personalized attention; Basic Training's staff are sticklers for form and safety, so you get the most from your workout. Plus, with classes four days a week, held in the mornings and the evenings, you're bound to find one that fits your schedule, whether you prefer to watch the sun rise or set in scenic settings around San Francisco.