Effective learning often requires learners to invest effort over time, yet this effort is fragile: learners misinterpret the effort as learning difficulty or avoid effective strategies that demand this effort. In this talk, I bring together three lines of my research on instructional-material design, retrieval practice, and self-regulated learning to examine how effort can become productive rather than be a mental load that is hindering learning. We will discuss how the design of instructional materials can support sustained and ongoing engagement, how demanding retrieval practice can promote consolidated comprehension, and how self-regulated learning interventions can help learners select, monitor, and maintain effective study strategies. Across these areas, I argue that educational psychology should not simply aim to reduce mental load but should also aim to help learners invest effort in ways that support engagement, comprehension, and lasting learning.