This question was originally posted on Quora.com and was answered by Avi Estrin, The Reformed Student, Project Manager, Sydney Uni Why does studying for 6hrs make me more mentally tired than working for 6hrs? Why does studying math make me more mentally tired than studying business? I’ve always been interested in the relationship between tasks and mental exhaustion. Because when we are mentally exhausted we are unable to study or work effectively. Each of us has a different capacity for working and studying effectively. But what it comes down to is this: The amount of mental effort required for each task. The more complex you find a task, the more mental effort required. I have always found studying mentally tiring. The challenge of learning complex concepts and being focused for long periods of time requires a high mental effort. My work, on the other hand, has a variety of tasks ranging from complex design reviews to easy administration tasks, such as emails. But certain days can vary, and what makes all the difference is how complex we find something. For example, some days at university I could only study effectively for 4 hours, because I was studying complex financial equations that I found challenging. And some days at work I could be effective for 8hours+ because the tasks were routine and easy for me. The key is to understand which tasks require most mental effort, and how your body and mind respond to them during the day. Once you understand this, you can start scheduling your tasks to suit. At work I allocate complex analytical tasks in the morning when I am most alert and mentally energetic. Then in the afternoon when I am more mentally tired I will do administration tasks such as emails. When I studied, I wanted to give each subject my best effort. So I developed a weekly timetable that allowed me to study each subject both in the morning and afternoon. For example, I studied Marketing on Tuesday morning, and in the afternoon on Wednesday: Of course, we cant be in full control of our schedules all the time, but the above methods are good general rules to follow. In addition to allocating tasks, I try to increase my capacity for mental effort. This helps me study or work effectively for longer. To do this I focus on sleep, eating healthy, exercising, taking regular breaks, and using rewards as motivation. Whether work or study, it’s your mental effort and discipline that will dictate how long you can be effective. Source
