If your goal is to lose weight then your first priority is to learn how to burn calories. Weight loss only occurs when you burn more calories than you take in. This is how you can burn calories all day long.
First, to burn calories you should keep a record of your heart rate because the higher you heart rate the faster you will burn calories. To calculate your maximum heart rate you subtract you age from 220. Your target heart beat rate will be 60%-85% of your maximum heart rate. A forty-five year old woman would take 220-45 and she would get the number, 175. The highest target heart beat rate that she should be Sonus Complete exercising at is 85% of 185, so take 0.85 x 175= 148.75. 60% would be 0.60 x 175=105. So a 45 year old woman should be targeting to exercise with a heart rate between 151 beats per minute to 148 beats per minute. Realize the higher the heart rate, the more calories that will be burned during the exercise. The best way to track this is by buying a heart rate monitor which will track calories for you during any given exercise.
Interval training is the next best way to burn calories. Before you despair at the thought of sweating it out on a treadmill, this can be a lot easier than you think. During interval training you in effect alternate high intensity exercise with lower intensity exercise. Take swimming as an example. You would swim for 4 laps at 85% of your maximum heart rate and then swim 8 laps at 60% of your maximum heart rate. This way you tend to burn calories at a faster rate because your heart has to move between intense exercise and recovery. The great news is that you will burn more calories throughout the day because your body has had to work harder. Of course having a heart monitor really helps but it is not essential because you will feel you heart pumping faster and harder during the intense phase.
Most people make the mistake of keeping to the same exercise routine. You will burn more calories by changing your exercise routine every few weeks. When you do the same exercise over a long period, your body gets accustomed to it. You learn the movement, you muscles get more efficient and so therefore you get less tired. Humans (and animals) are adaptable and increased efficiency means that over time, you will start to burn less calories doing the same amount of exercise.