Typically, it is best to do cardio
after a workout and chose days to run exclusive of working out.
While it is recommended to warm up with some light cardio before exercising, it
is still better to do resistance training before a cardio routine. The success
of resistance training is dependant upon the amount of stress you are able to
place on the muscle. The more energy reserve you have, the more work you are
able to do, the more stress you are able to place on the muscles. By saving the
cardio portion of your workout routine for last, you are able to ensure adequate
energy for resistance training.