Running motivated by an addictive mechanism may overpower the sensible, beneficial approach to exercise. Neglect of family responsibilities and relationships may occur as a result of this addiction. Thirty-five marathon runners and their spouses were studied; 22 of the runners were women and 13 were men. Each runner and spouse completed the dyadic adjustment (DAS) and running addiction (RAS) scales; the spouses were asked to rate their own dyadic adjustment and the runners' addiction. Findings indicated little relationship between the runners' RAS and DAS scores; however, there was a significant negative relationship between spouses' rating of the runners' RAS and their own DAS, (r=-.59, p < .001). The relationship between higher perceived levels of running addiction in the spouse and lower DAS scores was stronger in those spouses who did not run; (r=-.61, p < .01) and for male spouses of female runners; (r=-.67, p < .01).