Research within the Cognitive load theory (CLT) framework typically assumes motivation as a precursor to learning, rather than an outcome of instruction. In this study, we observe changes in learners' motivational beliefs as outcomes of their cognitive processes, through CLT lens. Using double-blind quasi-experimental design, we manipulate the level of cognitive load of instruction and assess changes in self-efficacy from pre- to post-intervention. Data from students enrolled in an undergraduate biology course (n=2,078), showed that students in the treatment condition revealed significantly higher performance and self-efficacy scores. However, self-efficacy was not significantly related to performance. These findings present a foundation to further investigate connections between historically distinct theoretical frameworks such as CLT and social cognitive theory