- Anxiety is common among people with a disability in general. Several studies have indicated that anxiety states may lead to hypokinesia and a 'sedentary' lifestyle. Anxiety reduction may improve the quality of life of people who suffer from intellectual disability (ID), as well as reducing health and social care expenses. Objective: To determine the effectiveness of physical activity interventions on reducing anxiety and improving quality of life (QoL) of persons who suffer from mild ID and anxiety. Methods: The sample consisted of 24 participants with the dual diagnosis of mild ID and anxiety. Participants were randomly assigned to one of three groups: aerobic training (n=8); leisure activities (n=8); and control (n=8). The aerobic programme (experimental group) consisted of three ergometric bicycle or treadmill sessions per week over a 6-month period (26 weeks).The leisure programme consisted of a varied range of activities (i.e. games and general exercises). The psychometrically sound, Hamilton Anxiety Scale (HAM-A), was used to quantify the severity of anxiety symptomatology and QoL. Results: Of the 24 participants, 19 participants completed the programme (experimental group n =7, leisure group n=5, control group n =7). However, only 16 participants agreed to complete the HAM-A. After 6 months only the experimental and leisure groups showed significant improvements (p<0.05) in the HAM-A. Conclusions: The implementation of an aerobic physical training programme or leisure structural activity programme for individuals with ID significantly and clinically reduced their level of anxiety. These authors could validate their hypothesis that foresaw a positive relationship between a psychiatric disorder, such as anxiety, and physical activity.