Previous studies show that people with intellectual disability (ID) appear to have impaired postural stability, a lower level of physical activity, and lower aerobic capacity compared to persons without ID, limitations that could affect their health. This study investigates these physical functions and their associations in a group of young people with ID compared to an age-matched group without ID. In total, this cross-sectional study included 106 high school students (16-20 years): 57 students with mild to moderate ID and 49 age-matched students without ID (control group). Tests were performed for postural stability, level of physical activity, and aerobic capacity. Both females and males with ID had significantly lower estimated maximum oxygen uptake (l O2/min) (p< 0.001 for females and p=0.004 for males) and a lower aerobic capacity expressed relative to body weight (ml O2/ kg*min) (p< 0.001 for females and p=0.012 for males) compared to age-matched peers. Analyses of associations were made using the Pearson’s correlation coefficient and multivariate linear regression analysis. No significant associations could be found. Physical status appears impaired for young people with ID and functions, such as postural stability, should be evaluated separately.