I am taking a jump rope "class" through the local college and my instructor started us out with twenty minutes, but about every three minutes (after each song) we take a thirty second active recovery break. It's pretty intense when you first start but after a few weeks you can increase the time by 5-10 minutes and you will find you don't require the full active recovery break. He also recommended that we only jump once or twice a week because it is pretty hard on your joints. I'm heading to my class soon- I look forward to it all week!
Re: Jump rope