The included studies enrolled between 34 (Holmgren 2010) and 170 (Green 2002) participants, with a median sample size of 119 participants. Age (mean: standard deviation (SD)) of the participants for the experimental and control groups ranged from 57 years (11) (for both groups) in Lau 2012 to 78 years (8) and 79 years (8) respectively in Holmgren 2010. For one study (Lau 2012), the mean age of the participants was under 60 years, two studies (Dean 2012; Marigold 2005) had a mean age between 60 and 69 years, and in the remaining seven studies, the mean age was 70 years or older.