Previous research into the role of exercise motives (what people want from exercise) has overlooked the possible role of gains (what people get) and hence the possible benefits of motive fulfillment (when people get what they want). To redress this imbalance, we examined the additive and interactive effects of motives and subjective gains on exercise-specific outcomes. Young adults (N = 196) completed measures of exercise motives and gains, and exercise behavioral regulation, amount, satisfaction, and intention. Four representative motives/gains were selected: appearance, positive health, challenge, and affiliation. Path analysis was used to test the effects of motives, gains, and their products (the interactive effects) on behavioral regulations, and thereby exercise amount, satisfaction, and intention. Controlled regulation increased with appearance motive, unless appearance gain was high. Controlled regulation had a negative effect on exercise satisfaction. Autonomous regulation increased with positive health motive, provided positive health gain was high; with challenge motive and gain; and with affiliation motive. Autonomous regulation had positive effects on exercise amount, satisfaction, and intention. The study corroborates previous findings about the effects of motives. It establishes the value of also studying gains, as moderators of the effects of motives, and in their own right. The findings are interpretable in terms of self-determination theory. Exercise promotion could be more effective if it focused on gains in conjunction with motives.