Both of these could work. For example, after reading the book, I stopped showering unless I worked out for 30 minutes on my Concept 2 rowing machine and I have

Both of these could work. For example, after reading the book, I stopped showering unless I worked out for 30 minutes on my Concept 2 rowing machine and I have been very consistent about rowing since linking those habits. The rowing machine is also more convenient than running because it is not dependent on weather, so that follows another principle--make it easy to do the right thing.