The purpose of this study was to examine the influences on the affect of parents of individuals with intellectual disabilities through participation in an intensive sport program. Six parents of individuals with intellectual disabilities who participated in a table tennis program as a family (along with the disabled individual) were recruited to serve as participants in this study. The program involved performing three sets of table tennis training, each lasting twenty minutes. Two measures were employed, namely the Waseda Affect Scale of Exercise and Durable Activity (WASEDA; Arai et al., 2003) and the Feeling Scale (FS; Rejeski, 1985). These are exercise-specific affect scales that consider affect with respect to sport bouts. WASEDA measures three types of affect: negative affect, positive engagement, and tranquility. FS is a measure of pleasure/displeasure. This study involved a 2 (condition: participating in the sport with the disabled individual/watching the disabled individual playing the sport)× 2 (time: before/after) repeated measures design. The participants were rated on the basis of WASEDA and FS measurement scales both before and after the program in each condition. ANOVA demonstrated that positive engagement and pleasure were enhanced by participating in the sport program rather than by merely watching it being played. These results suggest that actual participation in table tennis is more beneficial for mental health than merely watching it being played.