Research appearing in the journal Sleep (2008;31(7):1001–1008) looked at the sleep quality in 112 senior citizens between the ages of 59 and 86. The subjects had moderate sleep complaints, but had not been diagnosed with insomnia. The subjects evaluated their sleep quality with a questionnaire, the Pittsburgh Sleep Quality Index, that assessed sleep quality and duration. The subjects were then divided into two groups and received either training in tai chi chih (a Westernized version of tai chi) or were enrolled in a health education class for 25 weeks. At the end of the 25 weeks, those receiving the tai chi chih training reported slightly more improvement in sleep quality than the group enrolled it the health education class.