And while many consider taking the plunge into one or the other, they often find that choosing between the two can be confusing — which better suits one's fitness needs, body and lifestyle? Both are considered mind-body exercises, meaning that one should be mentally engaged while doing the physical work. Both employ breathing techniques. Both incorporate resistance for toning muscles. Both are used therapeutically. Both are slow, intense routines that can be done through classes or one-on-one training. And both can produce lean, toned bodies.

Yet there are significant differences between the two.

• Traditional hatha yoga features a series of static poses along with breathing techniques and meditation emphasizing an inward focus. Although hundreds of different forms of yoga exist, from restorative to power, the essence of the practices is the same.

A yogic lifestyle also emphasizes good nutrition and a holistic approach to wellness. With continual practice should come increased flexibility, overall muscle toning, improved balance and better ability to handle stress.

• Pilates is a series of regimented exercises that focus on using the core muscles of the trunk. Its roots date back to the early 20th century when Joseph Pilates developed a system (adapting some yoga techniques) to help rehabilitate hospital patients during World War I. Years later dancers adopted it as physical therapy.

Yoga exercises may use music, chanting and meditation in a self-contemplative approach to easing daily stress and living a healthy lifestyle. Myung J. Chun • Los Angeles Times

Although healthy living is often emphasized in Pilates, "you could be drinking a Pepsi while you're doing it," says Ralph La Forge, an exercise physiologist and spokesman for the American College of Sports Medicine. "In terms of lifestyle management, it's not as stringent."

La Forge separates the two this way: "If I were an athlete and I wanted better function, I'd go with Pilates," he says. "If someone has physical performance goals, those have to do with good posture and strong abdominal muscles. Pilates is more about musculoskeletal health."

Yoga, however, would be his choice "if someone needed to change their lifestyle, if there are overall health and lifestyle goals — someone who has had their first heart attack or has high blood pressure or diabetes."

How yoga and Pilates are used therapeutically supports La Forge's beliefs.

• Pilates in a physical therapy setting helps people bounce back from injuries.

But the true differences between yoga and Pilates may come down to the distinct approaches each takes to discipline.

• Yoga classes often use music and sometimes integrate chanting or affirmations, which address the meditative side.

• Pilates usually skips the music and the talk, taking a more pragmatic slant.

Yoga "is a journey of self and experimentation," says Leigh Crews, a Georgia-based yoga instructor and former Reebok program developer in yoga and Pilates. "You can experiment with holding your hip here or there, and experiment with what it feels like to get your hips level in warrior pose." Pilates, with its more regimented form, is less experimental and more goal-oriented: "You're striving to get in alignment."

Pilates is practiced in structured sets and reps, and yoga is not, says Crews, a Georgia-based yoga instructor and former Reebok program developer in yoga and Pilates. "Pilates is a very ordered and structured way to exercise. So people need to figure out if they want an instructor counting reps and leading them through a very organized series of exercises, or something a little more free-form. Yoga does have a built-in structure, but it isn't built so much around numbers."

Some instructors notice that certain personality types are drawn to yoga or Pilates.

"If someone is more comfortable being in a contemplative state, or at least with an inwardly directed focus, they'd probably gravitate more to yoga," says

Elizabeth Larkam, a Pilates instructor in San Francisco and spokeswoman for the American Council on Exercise. "If someone is more accustomed to looking outward and addressing external stimuli, then they probably would be more at ease with Pilates."

Which is not to say that all type-As are drawn to Pilates because it's more regimented, and laid-back sorts like yoga for its calming effects. Some seek a 180-degree twist from the pace of their daily lives.