The health benefits of tai chi chuan were largely explained through the lens of traditional Chinese medicine, which is based on a view of the body and healing mechanism not always studied or supported by modern science. Today, tai chi is in the process of being subjected to rigorous scientific studies in the West. Now that the majority of health studies have displayed a tangible benefit in some areas to the practice of tai chi, health professionals have called for more in-depth studies to determine mitigating factors such as the most beneficial style, suggested duration of practice to show the best results and whether tai chi is as effective as other forms of exercise. Researchers have found that intensive tai chi practice shows some favorable effects on the promotion of balance control, flexibility and cardiovascular fitness. Tai chi's gentle, low impact movements burn more calories than surfing and nearly as many as downhill skiing.