Pilates and tai chi are quite different forms of exercise, and ideally, it would be great if you could practice both. Pilates focuses on toning and strengthening the core body muscles, while tai chi focuses on drawing energy into the body and circulating it efficiently. Tai chi is good for stress reduction, and the Pilates style of slow movement also has a calming effect. Your choice depends on your fitness goals.
Stretching and strengthening are at the heart of the Pilates system. It aims to improve your balance, flexibility, muscle strength and posture. There's some evidence to suggest that it's a good form of exercise for anyone with recurring lower-back pain. The core stabilizing exercises tone and strengthen the cylinder-like muscles around the lower trunk to give the back more support. You don't need to be super fit to start a Pilates class, and Pilates is suitable for all age groups because the exercises are gentle and low impact.
Tai Chi Benefits
Tai chi focuses on a specific breathing method and on sequences of slow, graceful movements that encourage energy, or "chi," to flow around the body. Good chi flow makes each body system healthier, according to traditional Chinese medicine. Although it is actually a martial art, in the west and in China, tai chi is more frequently practiced for its health-giving benefits. Tai chi is particularly beneficial as a form of stress relief. Older people can benefit from the way tai chi's moves promote balance, helping to protect them from life-threatening falls. Like Pilates, tai chi is suitable for all levels of fitness and is a good way to get going if you've been inactive for some time.
Not For Weight Loss
Because both Pilates and tai chi are slow and low impact, they are not ideal forms of exercise if weight loss is your goal. For example, in a one-hour tai chi class, you typically burn between 219 and 327 calories, depending on your weight. A study published by the "American Journal of Sports Medicine" suggests that students burn about 360 calories during 60 minutes of intermediate-level Pilates exercises, which is about equivalent to walking at 4.5 miles per hour. Again, your weight determines how many calories you burn, with heavier people burning more.
The Eastern Element
Although Joseph Pilates used elements of yoga and martial arts in developing his system, it is primarily based on Western principles of anatomy and physiology and there is no belief system involved in its practice. Tai chi is based on Eastern Taoist philosophy and the principles of traditional Chinese medicine, which teaches that meridians -- a system of energy channels -- run around the body and that blockages in these channels cause ill health. Tai chi's exercise sequences are also based on the Taoist world view, in which the practitioner aims to achieve the harmony and balance represented by the yin-yang symbol. You do not have to believe in Taoism to practice tai chi, but some sympathy with its philosophy may help you to enjoy it more.