Another reason I'm a fan of this workout is that it's only 20 minutes, which makes it easy to do when you have some spare time. I find I can do this while watching tv or sometimes on my lunch break (depending on how motivated I am that day).
On a side note, it's like 15 degrees colder than it usually is where I live and I am not okay with this. I'm doing all these toning exercises for some warm weather and I'm being denied it. Just felt like I had to put that out there so that maybe the sun will show it's face around here!
Let me know what some good arm workouts are as I'm fairly new to this! XO