cross trainer vs 30ds??

NC1994

This may be a weird question, but which of the above is more 'effective'??

I'm basically trying to lose my belly fat and tone up all around, and i know you cant spot reduce fat, but which one of these will help me reach my goals quicker? I know it would be great if i did them both but I just don't have the time!!!

I have a desk job, so besides walking to work and running errands in the evenings and weekends, i dont actually do any more exercise!

I just dont wanna waste my time on the cross trainer for 30 minutes when its really not doing me much good.

Im 19, 157lbs, and eat 1400 cals a day if that helps