In the current paper we focus on the role of physical fitness in the life stress process for both psychological and physical well-being. The major research question posed in the current study is: Does physical fitness deter distress in a model containing the major components of the life stress process? That is, do individuals who exercise show higher levels of well-being than those that do not exercise? Is this relationship independent of the stress they experience and the resources they possess? Using data from a representative community sample, the current study finds that physical fitness is directly related to both psychological and physical distress. The more a person exercises, the less psychological and physical symptoms he or she manifests. Physical fitness is associated with decreased distress. This finding holds up, even when stressors and psychosocial resources are included in the model. While physical fitness was not found to mediate the effects of stressors on distress, there was some evidence of a moderating effect of fitness in the stressor-distress relationship, both for psychological and for physical distress. That is, fitness served to buffer the effects of stressors on both psychological and physical distress. In addition, physical fitness is associated with psychological resources that, in turn, are associated with lower levels of distress. The more a person exercises, the greater the self-esteem. Thus, in addition to directly deterring distress, physical fitness was found to have the potential to indirectly deter distress through its positive association with the level of psychological resources (i.e., self-esteem) that individuals possess. These and other findings are discussed in the context of the life stress paradigm. Implications for future stress research are presented. (Contains 5 tables, 2 footnotes and 1 figure.)