Since it is summer time I want to lose a few pounds & firm up so I've been doing a simple but effective (I hope lol) strength training routine and have been riding an exercise machine bike (it has the moving arm things too where your arms move back and forth in sync with the pedals) for 30 min. every day for my cardio. I've read before that doing the exact same thing for your cardio isn't too good because your body gets used to it and stops showing result. Should I stick with riding the exercise bike for 30 min. daily or do something different?