I finally got to try out my new 4lb jump rope. I didn't think it would be that much harder due to momentum once you get the thing spinning, but I was wrong. For one you've got to hold on tight to keep it from flying out of your hand and it moves like a rope so it's not always 100% symmetrical, making things harder. It's a serious upper body workout while jumping rope. My biceps and shoulders were burning after jumping (for only about 2 minutes total at that) and my rear delts are sore as hell today. I can normally jump rope in 3 minute rounds like it's nothing. This thing whooped me. Here's a link to it on Strength Systems website: http://www.strength-systems.com/item...=13&styleid=85
Has anyone else ever used one of these? If not, I would recommend it as another twist to the workout.