The authors of a paper titled "Introduction to Evidence Based Recreation Therapy" say the following:
There are limited examples of evidence-based intervention studies in the recreation therapy literature (Carruthers & Hood, 2002; Fitzsimmons & Buettner, 2003, Kolanowski, Litaker, & Buetnner, 2005; etc, and many more are needed. Another challenge to an evidence-based practice approach for recreation therapy is the lack of research evidence about the effectiveness of specific recreation therapy interventions for particular conditions or diseases.
Because of this fact, you may need to think of synonyms for "recreation therapy" like "play therapy" or "exercise therapy" in order to find articles or guidelines on the topic.
Buetther, L & Fitzissions, S. (2007) Introduction to evidence based recreation therapy. Annual in Therapeutic Recreation. 15, 12-17.
PubMed includes all of Medline plus general science, chemistry and databases for the biomedical researcher.
CINAHL is a great database for novice searchers though much of the content is geared toward the discipline of Nursing. It includes the full text of many nursing articles, but also "relevant materials from biomedicine, management, behavioral sciences, education, & consumer health."
PsycINFO provides access to international literature in psychology and related disciplines.
Physical Education Index includes journal citations on topics such as: biomechanics, kinesiology, coaching, curriculum, dance, health, history, law, measurement-evaluation, motor learning, patents pertaining to sporting goods and exercise equipment, perception, philosophy, physical education, physcial fitness, physical therapy, recreation, research, sports activities, sports psychology, sport sociology, sports, sports medicine, teaching methods, and training
SPORTDiscus includes citations and abstracts covering all areas of sport, physical fitness, exercise, sports medicine, physical education & training. Full-text contains content from books, book chapters, conference proceedings, and journal and magazine articles.
ERIC (via ProQuest) is the premier U.S. database of education literature. Sponsored by the U.S. Department of Education. Includes journal (EJ) and ERIC Document (ED) citations with abstracts; full text of ERIC Documents from 1993 to present.
Leisure Tourism Database includes worldwide information for all those interested in the research and strategic development of leisure, recreation, sport, tourism, ecotourism, and hospitality activities, facilities, facilities products and services.