Horse riding is a popular, high-impact recreational activity that occurs worldwide. The United States and Australia have a long history of recreational horse riding in protected areas and controversy accompanies this activity in both countries. This review describes and critiques research to date, and then draws out the implications for future research and management. Previous research has been experimental (using trampling lanes to determine impacts away from trails) and quasi-experimental (based on existing use of trails and describing impacts). The off-trail experimental research clearly demonstrates that horses can cause considerable damage. The trail-based quasi-experimental research also showed degradation from horses; however, critiques of this methodology make it more difficult to draw robust conclusions. In addition to biophysical impacts, social research based on surveying users has identified a number of issues associated with horse riding (e. g. conflict with other users) as well as exploring horse riders' preferences for management actions. A major gap in current research is evaluating the effectiveness of management actions, such as trail construction and codes of conduct. Recommendations for future research include more attention to experimental design, research across and into new ecosystems to improve the generalisation of findings, and attention to researching management effectiveness.
