I bought Jillian Michaels - 30 Day Shred a few weeks ago, after reading about it in the blogosphere. Let me say this, after I finished the first workout, I was too sore to lift the soap in the shower. It is challenging, but also very effective. I regularly run and lift weights but wanted a bit of a change. After only three weeks, I'm already seeing new little muscles in my arms and legs. The best part is that each workout is only 20 minutes long. You can do anything for 20 minutes. It's easy to fit into the day. I'm very happy with this DVD. Best of all, after seeing some improvement in only a few days, I'm highly motivated to take it up a notch. And, I kept having to go down a size when I was trying on clothes the other day. Nice! Just a note that I'm using 8 pound hand weights because it's what I had.