BackgroundIndividuals with intellectual disabilities (ID) have a reduced physical health compared to the general population, and one of the main contributors is inactivity.AimTo investigate how 14 weeks of physical activity (PA) in a real-life setting affects cardiovascular fitness, body composition and bone health of adults with ID.MethodsAdults with ID were recruited into a PA-group or a control group (CON). The PA-group participated in 14 weeks of PA. Body composition, cardiovascular fitness and bone health were assessed before and after the intervention.Outcomes & resultsCardiovascular fitness and body composition improved from pre to post within the PA-group: Heart rates (HR) during the last 30 seconds of two increments of a treadmill test, were reduced (3.2 km/h: -4.4 bpm, p<0.05; 4.8 km/h: -7.5 bpm, p<0.001) and fat mass was reduced (−1.02 kg, p<0.05). Between-group differences in favour of the PA-group, were observed in whole body bone mineral density (BMD) (0.024 g/cm2, p<0.05) and in BMD of the left femur neck (0.043 g/cm2, p<0.05).Conclusions & ImplicationsFourteen weeks of PA increase cardiovascular fitness, reduced fat mass and improved BMD in the weight-bearing skeleton in the PA-group. Increased and regular PA seems to be a promising tool to promote physical health in adults with ID.What this paper addsThis paper underlines the importance of including physical activity in the everyday lives of individuals with intellectual disabilities. The health impact of physical activity performed outside controlled research laboratories needs further investigation, and therefore this paper sheds light on physical activity performed in a real-life setting. Our results indicate a positive impact of physical activity on the cardiovascular system and body composition, as well as bone health. The question of how of bone health of adults with intellectual disabilities responds to physical activity is largely understudied in intervention designs, and this paper includes state-of-the art investigation of development in bone mineral density after participation in varied physical activities. These results give promise and indicate a positive impact of the intervention on the bone health of the participants.