Labor; effort; the work or toil required to accomplish a task, often involving time and energy.
この研究には多くの労力が必要だ。
This research requires a lot of labor/effort.
労力を惜しまず準備を進めた。
We prepared without sparing any effort.
単純作業に労力をかけすぎない方法を考える。
Think of ways not to spend too much effort on simple tasks.