Many people get discouraged after spending time on the treadmill or out on the streets jogging to lose weight without the proper results. Frustration and doubt come along because they are not provided with the right information about what it takes to burn fat with exercise.
The body is a great machine and you have to stimulate it in a proper manner to get the desired outcome. What I am saying is that not every effort has the same effect, and understanding this is crucial to your success. There are two important concepts you have to keep in mind the next time you start training, which will make your routines enjoyable and goal oriented:
1. Time: I don't want to make any complicated explanation here. The fact is that your routine should last from 45 to 60 minutes in order to start burning fat. Before that time your body has some other energy sources, so this is probably the most important reason you aren't getting the results.
2. Intensity: You have to be aware of your hear rate to measure this parameter. Your exercise must make your heart pump faster (approximately 60 to 80% of your MaxHR). If you run for a long period of time but at a minimum level of intensity, you won't get results either.
You have to be aware that weight loss is a process and that the best way of doing it is with a good combination of diet and exercise. If you try to do it in a week or two, it is possible you may get frustrated by the lack of results. Take your time to adjust your routine and let your body get used to it. Don't push your limits!
If you don't know how to start, I found a good training system that can help you with the process.
Good luck and good run!