I also combined my running with a fair bit of resistance training - since resistance training is crucial for building muscle.
And Finally, all these exercises were combined with a sensible diet that combines a good mix of the essential macro-nutrients (proteins, carbohydrates and fats).
In these 4 months, I have learned a lot of things. However, the most important thing I have learned is that I am on the right path. The progress is not dramatic but it is there. Every day, I find that I can run a little bit longer, or a little bit faster, or that I can push weights that are a little bit heavier than what I pushed last week. And ever so slowly, the definition of the abs begins to take shape.
I really don't know how long it will take me to reach my target. Perhaps a year based on my current progress. That's just fine by me. I never had any abs in my life so it is all the more difficult, because the fat that I accumulated over the many years has become ingrained in various organs of my body. Getting rid of all that stubborn fat is not going to be an easy task. But I knew this when I started this challenge.
If someone had asked me 2 years back for my ideal body shape, I would have happily settled for the body that I have today. But that was 2 years back - when I did not know what my body is actually capable of. Now that I have the knowledge, the quest for the perfect body will go on.