Background: The life expectancy of individuals with intellectual disabilities (ID) is reduced compared to the general population, and one of the main contributors to earlier death is inactivity. 

Aim: To 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. 

Methods: Adults with ID were recruited into a PA-group (N = 52) or a control group (CON, N = 14). The PA-group participated in 14 weeks of PA, and body composition, cardiovascular fitness and bone health were assessed before and after the intervention. 

Outcomes and Results: Cardiovascular 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). A between-group difference in favour of the PA-group, were observed in whole body bone mineral density (BMD) (0.024 g/cm², p<0.05). 

Conclusions and Implications: Fourteen weeks of PA performed in a real-life setting increased 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.