It matters on how much you weigh how much you want to lose and what your goal is while doing this excercise?? But by not knowing anything about you 10 to 45 min is good I think. Something you do that will give you a workout but take it easy if its your first time start slow and less time gradually move your way up the speed and time good luck

Start out by walking, then jog for a few min until you cant anymore, then walk to cool off. Every other day do this and try to build up your jogging time.

<3
gaby