54 (95% CI 0.38 to 0.70, p < 0.001, random effects meta-analysis, I2 = 12%). There was a bigger effect on strength in the trials in which the programs targeted strength specifically (by using weights with a moderate to high intensity, ie, using a weight so heavy that only 8–12 repetitions could

be done without resting). The pooled effect from the 7 programs that did not target strength specifically was 0.32 (95% CI 0.09 to 0.55) whereas the pooled effect from the 10 programs that did specifically target strength was 0.68 (95% CI 0.49 to 0.87). This check details difference was statistically significant (effect of strength in meta-regression, p = 0.045) ( Figure 2). The meta-analysis of balance outcomes included six trials and found a moderate effect of physical activity on balance (SMD = 0.52, 95% CI 0.24 to 0.79, random effects meta-analysis, I2 = 51%) (Figure 3). The meta-analysis of endurance outcomes included six trials (8 comparisons, as one trial had three groups) and found a moderate effect of physical activity on endurance (SMD = 0.73, 95% CI 0.50 to 0.96, p < 0.001, random effects meta-analysis, I2 = 65%) ( Figure 4). Only one trial (Pereira et al 1998) reported on the effects of a physical activity program on long-term falls.

Pereira et al 1998 showed a non-significant decrease in the occurrence of falls over the last 12 months (RR 0.82, 95% CI 0.53 to 1.26). Of those who received a walking program 15 years earlier, 27% percent reported falling in the year prior Liothyronine Sodium to follow-up, whereas 33% of selleck kinase inhibitor the control group reported falling in the past year. The rate of women reporting more than one fall over the last 12 months was also lower in the walking group (23%) when compared to controls (30%) but this difference was not statistically significant (RR 0.76, 95% CI 0.48 to 1.23). Adherence to the physical activity programs, presented in Table 2, was assessed in 12 of the 22 included trials (Asikainen et al 2006, Bemben et al 2000, Heinonen et al 1998, Janzen et al 2006, King et al 1991, Klentrou et al 2007, Levinger et al 2007, Mitchell et

al 1998, Sallinen et al 2007, Shirazi et al 2007, Singh et al 2009, Uusi-Rasi et al 2003). In general, physical activity adherence (calculated as the percentage of completed physical activity hours, out of the prescribed hours) was greater than 80% (Asikainen et al 2006, Bemben et al 2000, Janzen et al 2006, Levinger et al 2007, Mitchell et al 1998, Sallinen et al 2007, Singh et al 2009), ranging from 48% (Shirazi et al 2007) to 96% (Levinger et al 2007). This systematic review found that strength, balance and endurance can clearly be improved by physical activity in people aged 40–65. The effect of physical activity on falls has not been well investigated in this age group. Most of the trials identified focused on strength and/or endurance training. This review found a moderate effect of physical activity on muscle strength.