It depends how heavy you are but it's about 90-130 calories that'll be burned in half an hour. Keep doing this, along with cardio (minimum of 30 mins) and you'll start to see results. It is also recommended that you should leave 2 days between each weights session, although doing cardio on these days is fine. As pastafreak says, muscle weighs heavier than fat so weighing yourself isn't the best way to record shaping up - measuring is.Lastly, give it time, it can take a good few months before you may see results and Good luck!