I have been using Firm tapes(SL, TT, FS and BC 3in1 mix)every other day and TaeBo adv. for cardio. I love the Firm, but the Tae Bo tends to hurt my arms(I think the movements are too fast for me). I have read very positive things about Cathe tapes and would like to try them. I already have a square step box that's 4 to 14 inches but only 14 inches in diameter. Would this be appropriate to use with Cathe tapes? I would like a suggestion on a good Cardio tape to use in between strength days. I am an intermediate excerciser and I like a no nonsense workout. I need to make good use of my time. Is there a cardio tape that doesn't have a lot of jumping? I find my knees tend to hurt when I jump alot. I would also like a suggestion on the best strengh tape. I am only able to get a few tapes so I would like to get the the most effective one. Thankyou for your suggestions.