One thing that plagued me, however, was how I still remained prone to lower back pain while running long distances. Not all the time, but definitely often enough to be a bother. I couldn't understand it though; I was specifying my training in order to prevent this back discomfort. Why wasn't it working?
The solution eventually came to me. When doing exercises such as planks or deadbugs, the core is always being trained to stabilize the spine through the hip's range of motion from 0 - 90 degrees, and nothing more. However, when you jog, sprint, skate, or doing virtually anything else active, we are constantly exceeding those 90 degrees, with the hip moving into hyperextension during activity rather than stopping at 0.
It should start to piece together now. Understand that, since the core hasn't been, at all, trained to stabilize during those extra degrees of extension, the integrity of the support breaks down and allows the spine to deform and extend itself, resulting in low back pain.
Now that we have figured out the problem, please enjoy the solution!