The most effective, and hardest to learn is jumping rope. If you want to use a machine here is something you should know:

Above burning calories you want to burn fat. (I’m assuming a bit here) Your body needs energy in order to do that, so it takes it from the glycogen that you store. Fortunately, and unfortunately, we store enough glycogen to keeps us going for 20-30 minutes. Once the glycogen is gone, then our bodies turn to the fat stores for energy. Translation: You have to do 30-45 minutes of cardio to burn fat. Another solution is to do your cardio first thing in the morning without any food in your system if you can. Your glycogen stores will have been depleted while you sleep, so there won’t be much to convert and your body will have to burn fat to keep going. If you are using the elliptical (my personal choice:^)) use the hand pulse monitor to make sure that you are in your target range. You can find target heart rate calculators on google. Good Job on doingn 45 minutes already, now just make sure that you are using all that glycogen, and you will be all set. Don’t forget to eat some carbohydrates after your workout as well, it’s when your body is most open to nutrients and it needs to replenish the stores, otherwise you will be weak the rest of the day.

Rowing,exercises most muscles

read tips on calorie burning and exercise to help you better on this site

#1 Cross country skiing
#2 Running