Check your health is a prevention intervention designed to create awareness and action on health condition with focus at physical activity at a population-level to 30-49 years of age. It consists of a behavioural and clinical examination followed by either (I) referral to a health promoting consultation in general practice (II) targeted behavioural programmes at the local Health Centre or (III ) no need for follow-up; stratified after risk-profile. The CORE trial (Check your health) aim to investigate effectiveness on health and social outcomes of the preventive health check and to establish the cost-effectiveness according to life years gained; direct costs and total health costs. A pragmatic cluster randomised controlled trial has been established to meet the aims and in total 10.600 individuals from 35 practices have been randomized in to two groups that will be invited in 2013-14 and 2017-18 respectively. The group offered the preventive health check in 2013-14 will constitute the intervention group and the group examined in 2017 - 18 the control group. A follow up of the intervention group in 2017 - 18 will provide data for the intention to treat analysis revealing the effect. Outcome measures are level of physical activity, risk of getting cardiovascular disease, sick leave and labor market attachment.