Yesterday was deadlift day for me at the gym. Deadlifts are hard and most people shy away from them for fear of hurting their backs. However, they are an essential exercise to strengthen core muscles including those that support your spine.
Every book has 15 scenes that form the core of the story. That core, also called the spine, forms the foundation of the story. Most people shy away from doing writing exercises to strengthen those core scenes. Those exercises require a lot of heavy lifting; lots of reading, writing and studying what others have done.
People who are willing to do the work, get the results.