Background: This systematic review aims to evaluate the long-term effectiveness of physical activity interventions targeted at healthy adults and to identify effective intervention components.
Methods: The systematic search in Pubmed, Embase, the Cochrane Library and Psycinfo identified literature published in English and German between January 2001 and June 2007. We included randomised controlled trials investigating physical activity interventions for healthy adults with a minimum study duration of 12 months. Two researchers independently assessed publications according to pre-defined inclusion criteria and methodological quality was rated according to the SIGN criteria. Study characteristics and outcome measures were extracted, and pooled effect estimates with 95% confidence intervals calculated.
Results: Of 5508 identified publications 25 studies met the inclusion criteria. There was substantial heterogeneity in study quality, intervention strategies and intervention effects. Compared to no-intervention and minimal-intervention control, gains in weekly energy expenditure and physical fitness of up to 975 kcal and 11% were achieved, respectively. Booster interventions were used in 16 studies.
Conclusions: There is evidence for long-term increases in physical activity behaviour and physical fitness. To improve uptake of physical activity additional tailored exercise prescription strategies seem promising. Booster interventions such as phone, mail or internet can help to facilitate long-term effectiveness.