Completing two tasks concurrently often leads to a decline in the performance quality of one or both tasks. However, an emerging body of literature suggests that cognitive-motor entrainment may alleviate dual-task cost and, in some cases, lead to a higher quality of psychological and physiological task performance than when the same tasks are performed in isolation. Through a theoretical review, primary experimental analyses, and secondary mediation analyses, the present dissertation seeks to understand how cognitive-motor entrainment may be used to enhance long-term memory retention through physical activity participation. In two crossover repeated-measures experiments, participants learned unique 40-word lists under three conditions: a cognitive-motor entrained, a traditional dual task, and a stationary control condition. In experiment 1, when participants learned words in a treadmill walking cognitive-motor entrained condition (words were presented on a screen every fourth stride), they retained more information during free-recall long-term memory assessments when compared to a stationary control ( main effect of time (F(2,70)= 65.87, p < 0.001, ηp2 = 0.65) and condition (F(2,70)= 3.63, p = 0.03, ηp2 = 0.10), no interaction (F(4,140)= 1.73, p = 0.14, ηp2= 0.05)). In experiment 2, when words were studied under the cycle ergometer-entrained dual-task condition (word presentation was matched to cycling patterns), they were more easily free-recalled during delayed long-term memory testing than the word lists studied under the traditional dual-task or control condition (main effect of time (F(2,70)= 94.07, p < 0.001, ηp2 = 0.73) and condition (F(2,70)= 3.87, p = 0.03, ηp2 = 0.10)). In both experiments, no conditional differences were found in relation to recognition memory (accuracy or confidence) or motor coefficient of variation performance (gait parameters or cycling cadence). A secondary analysis of the data evaluated whether baseline long-term memory ability mediated cognitive-motor entrainment’s mnemonic effects on long-term memory retention, but no effects of individual differences were identified. Altogether, these findings suggest that cognitive-motor entrainment may enhance long-term episodic memory retention regardless of the physical activity mode incorporated or foundational individual long-term memory differences. Further neuroimaging research is needed to clarify the underlying mechanistic effects of a cognitive-motor entrainment intervention and elucidate how the rhythmicity of stimuli presentation may confound the measured effects.