I also used to not clap because I thought that it was dorky.
Now I clap to stay on beat - then I also don't cheat the arms because you have to get them all the way there to make some noise.
I dropped my step this year (based on comments from you guys about joints and knees) and I find that I enjoy the workouts much more, my knees are loving it, and I'm happy enough to clap. I do have to keep my arms really maxed out to keep my heart rate up.
Melissa