Cross Trainer Advice

Hi

I am looking for advice, i have 36Lb still to loose, I have a cross trainer at home and do a 40 minute fat burn program each day, if I want to loose weight and tone up is it better to have less resisitence which means I can run faster, and have a higher heart rate or should I up the resistence which means I will run slower (do not want to end up with big muscle legs :happy: )

All advice welcome, thank you