Is Cardio Kickboxing a form of Strength training, cardio, or both?

This may be a dumb question but I will ask anyway. I do cardio 5 days a week and am looking for a way to spice it up (treadmill can get boring) and I also do a pretty strenuous strength training regimen at the gym with my husband who is bulking up right now. I have a cardio kickboxing DVD that I would like to use to change up my cardio routine, but I know it tones as well, so will that effect my strength training at the gym? Will that over work my muscles if I do the DVD 2 days a week to change my cardio routine? Any advice would be great.