I've always known in the back of my head that the extra pounds I'm carrying have impacted my cycling and that I have to work a little bit harder in order to keep up with a skinnier cyclist of comparable fitness. It's simple physics. Friction and gravity resist you as you go up a hill, so having more mass means gravity pulls you more, meaning you need more power to go up the hill. Being bigger also causes more surface area, which creates friction as air drags around you.
I knew this. I understood it cognitively, but I had never seen it quantified before. How big of a difference could a few pounds make, really? What I kept noticing in the leader boards over and over again was people with less power output besting my time. Again and again I would see things like this example below (my time shaded pink).
At first I was thinking, how is it possible that I put out more power but yet have the slower time? Then I realized that the pics of these people who bested me were all of people 50 to 100 pounds lighter than me. They were going faster because they didn't have as much gravity and friction counteracting their power. So, they required less power to go faster.
It's unrealistic for me to aspire to the ideal cyclists form because I just don't have the frame for it. However, I can still do a lot to improve my performance by shedding the extra pounds. And now I've got just a little bit more motivation to do so. Ironically, that motivation comes in the form of laziness. I don't want to work that hard (over 50 watts harder in the example above) for my slower results. I want it to come easier.