Journal of Aut&m and Developmental D&orders, Vol. 14, No. 1, 1984 The Influence of Vigorous versus Mild Exercise on Autistic Stereotyped Behaviors 1 Lynn Kern, Robert L. Koegel, 2 and Glen Dunlap University of California, Santa Barbara A major problem encountered in many autistic children is their high rate of stereotypic behavior, which has been shown to interfere with on-task responding and other appropriate behaviors. Since the experimental literature indicates that physical exercise can positively influence both ap- propriate and inappropriate behaviors, including the children's stereotypic behaviors, the purpose of this study was to investigate whether the specific type of exercise (i.e., mild vs. vigorous) would differentially affect sub- sequent stereotyped behaviors. The results demonstrated that (1) 15 minutes of mild exercise (ball playing) had little or no influence on the children's subsequent stereotyped responding, and (2) 15 minutes of continuous and vigorous exercise (jogg&g) was always followed by reductions in stereo- typed behaviors. These results are discussed in relation to cognitive, phys- iological, and educational implications. Numerous studies have suggested that certain highly stereotyped man- nerisms (such as hand and arm flapping, body rocking) of autistic and other severely handicapped children may be detrimental to these children's de- velopment (cf. Epstein, Doke, Sajwaj, Sorrell, & Rimmer, 1974; Koegel & Covert, 1972; Koegel, Firestone, Kramme, & Dunlap, 1974; Lovaas, ~This research was supported by United States Public Health Service research grants MH 28210 and MH 28231 from the National Institute of Mental Health, and by Research Contract No. 300-82-0362 from the U.S. Department of Education-Special Education Program. The authors are grateful for the contributions of Diane Gilcbrist, Julie Martin, Karen Sallus, Lynne Bonngard, Bill Krutzen, Lee Kern, John Burke, and Rob O'Neill. 2Address all correspondence to Robert L. Koegel, Social Process Research Institute, University of California, Santa Barbara, California 93106. 57 0162-3257/84/0300-0057503.50/0 91984 Plenum Publishing Corporation