Exercise! - Doing Slim in 6 and Gazelle on same day??

I was wondering if anyone knows if it would be better for me not to do the Slim in 6 exercises and like a hour on the Gazelle everyday or should I do them different days??? Since the gazelle is like my cardio workout and well the Slim in 6 is too, but I think that is building muscle also? Any insight would be greatly appreciated!!

In general, you shouldn't exercise continuously for more than an hour. If you want, you could do one earlier in the day and then the other later in the day?

I was doing like 30 mins on the gazelle in the morning, then going to work then when I get home doing the SI6 and then 30 more mins on the gazelle.