Not all studying is equal. You will accomplish more if you study intensively. Intensive study sessions are short and will allow you to get work done with minimal wasted effort. Shorter, intensive study times are more effective than drawn out studying.
In fact, one of the most impactful study strategies is distributing studying over multiple sessions (Newport, 2007). Intensive study sessions can last 30 or 45-minute sessions and include active studying strategies. For example, self-testing is an active study strategy that improves the intensity of studying and efficiency of learning. However, planning to spend hours on end self-testing is likely to cause you to become distracted and lose your attention.
On the other hand, if you plan to quiz yourself on the course material for 45 minutes and then take a break, you are much more likely to maintain your attention and retain the information. Furthermore, the shorter, more intense sessions will likely put the pressure on that is needed to prevent procrastination.