• Cardiovascular
• Sedentary
• Physical activity

It should be pretty obvious; movement is good, sitting still is bad. However, physical activity rates continue to fall across the world.1 As sports and exercise medicine practitioners, we could be seen as frontline soldiers in the fight against inactivity. As such, we need to be well armed with knowledge about the consequences of inactivity, about what can be done to combat it and about who we should be targeting. These themes are all covered in this issue which shines the spotlight on an increasingly researched topic in Norway—the relationship between physical activity and health.

We start with a study documenting the declining activity levels of British school children as they age from 10 to 14 years (see page 730). We hope their increased sedentary time is not spent in front of a computer or watching TV, because in their huge meta-analysis, Zhai et al show that these behaviours are associated with an increased risk of depression (see page 705).

Cardiovascular consequences of sedentary lifestyle have been assessed in two large Norwegian population studies, the HUNT3 study and the Oslo II study, discussed in E Berge's editorial (see page 702). In one paper from each study, both Chau et al (see page 737) and Holme and Anderssen (see page 743) highlight the association between sedentary behaviour and mortality risk. The latter study draws a fascinating parallel—showing that to reduce mortality risk, increasing physical activity levels is as important as quitting smoking. This may be a turning point, as in Norway (where the number of regular smokers has reduced by 40% over the past 10 years) the anti-smoking message seems finally to be getting through.

A big step towards this reduction of smoking in Norway is likely to have been the introduction of the Tobacco Act in 2004, which banned smoking in public places. Although it was controversial back then, similar laws now exist in 100 other countries. If national policy has proven to be effective in reducing smoking, what about increasing physical activity? This issue is explored by Fiona Bull et al (see page 749) who summarise and contrast the national physical activity promotion strategies of seven European countries, including Norway.

Community-level physical activity interventions, such as outdoor walking groups, also offer a wide range of health benefits. In their meta-analysis, Hanson and Jones (see page 710) show that walking groups have high levels of adherence, virtually no adverse effects, and lead to improvements in blood pressure (BP), body fat, body mass index, cholesterol and risk of depression. Time to get your walking shoes on? We think so!