Only used them once. Did it late in a session and didn't take long before my arms felt like lead. I see them nearly everywhere I go these days. Very commonly found piece of training apparatus.
some youngsters were using them in the fitness center today. Of course when they were finished they just left the rope laying on the floor and didn't bother to re-rack the weights they were using either:-( Which didn't sit too well with me since I finished my workout with a heavy farmer's walk ( seriously underutilized workout, forearm killer ) I have never used the ropes but I think the farmer's walk does a killer job on the forearms and overall strength ( what could be more functional than walking around with + 100lbs ?) I don't see the ropes hitting the legs and core like the farmer's walk.
Whats worth a try, is 2/ 4metre bungee cords, anchored at head height. Using the same principles, thumbs up or palms down moving backwards as you do it it 3" steps, its a killer great for speed too. Plus a lot cheaper equipment. :good.
If you look a the differnt types of excercises it will work legs and core. http://www.youtube.com/watch?v=18YTU-2Oz50
i used it for 8 rounds interval work. it works core and back muscles.. legs and forearms also if its done properly. very nice conditioning exercise