A study published in the International Journal of Clinical and Experimental Medicine shows that the fitness benefits of tai chi for older women only become obvious if they engage in long-term practice. After four months of exercise, most of the study indexes compared to dance and walking groups were found to have improved significantly, while those in the tai chi group showed no significant difference. However, after 12 months, the effects of tai chi were found to be more significant than both control groups.
Read the abstract of the study here: http://www.ncbi.nlm.nih.gov/pubmed/25035781