Background: Despite well-established benefits of engaging in regular physical activity, children and young people with intellectual disabilities are significantly less active than their age peers. Methods: Semi-structured interviews were conducted with two teachers of PE and two learning support assistants working in special schools in order to provide an insight into the physical activity tendencies of children and young people (CYP) with intellectual disabilities. Results: Access to and use of outdoor spaces was claimed to have a positive impact on the physical activity tendencies of CYP with intellectual disabilities. However, the schools we visited had limited indoor space, which impacted negatively on the duration and frequency of physical activity that CYP were able to engage in, particularly when space had to be shared because of timetabling issues and unfavourable weather. When it came to the "type" of physical activities, individual, self-initiated and self-regulated were favoured. Conclusions: We end by suggesting that the onus is on teachers and learning support assistants to think of creative ways of using limited indoor space. The use of dining and assembly halls may be one solution. So, too, may be more individualised physical activities because they are often better suited to the needs and capabilities of CYP, and can often be performed in limited space.