Episodic memory and inhibitory control deficits are prevalent among those with mild cognitive impairment (MCI). These deficits have been associated with worse functioning; however, the predictive utility of specific cognitive deficits vary. We investigated whether deficits of episodic memory and inhibitory control are associated with less physical activity and life satisfaction among people with probable MCI (pMCI). The study included 79 pMCI and 79 individually matched controls (HC) who participated in the Human Connectome Project - Aging study. Groups were determined based on MoCA scores (pMCI ≤ 23; HC ≥ 26). Participants completed the Go/No-go (GNG) and Face Name (FNT) tasks during functional MRI. Associations between GNG False Alarms (GNG FA), FNT Recognition Accuracy (FNT RA) scores, the International Physical Activity Questionnaire (IPAQ) and the PROMIS General Life Satisfaction (GLS) self-reports were examined. The pMCI group exhibited deficits compared to the HC on GNG FA (t (152.17) = -1.26, p = .05) and FNT RA (t (85.78) = 13.72, p < .001). Regressions revealed that neither the cognitive task scores nor the group differences directly accounted for significant variance in either IPAQ or GLS (p > .05). However, hierarchical regressions revealed that the interaction of these cognitive tasks predicted IPAQ (∆R² = 0.02, F(1, 78) = 3.74, p < .05). Despite confirmation of expected cognitive deficits, their effects on physical activity and general life satisfaction are complex and more difficult to detect. Therefore, MCI deficits appear to confer complex functional risk that may be detected on screening before they clearly impact functioning. Findings underscore the utility of screening to facilitate more effective earlier interventions.