Use the two-minute rule to establish habits for difficult activities.
The secret to establishing habits for difficult activities like going to the gym or studying hard is establishing simple habits, over time, that will eventually get you to the more difficult activities. These simple habits should take less than two minutes and be easy to do. So instead of reading a chapter, read a page. Instead of doing a full workout, take your gym stuff and leave the house. Instead of running a marathon, wear running shoes.