If you are working out then I think it's safe to assume you are looking for some change, some good results...something!?
If you are working out and NOT doing zone training or if you don't have a good diversified cardio routine, it will be very difficult to get optimal results.
In this video I outline the major types of cardio training that should be included in your routine. The name of the game is diversity. If you keep doing the same old cardio, day after day, week after week, your body will adapt. And then you will not see improvement.
For real change to occur you need to keep challenging your body in different ways.
Watch the video for more details on what to include in a workout routine and how to use apps like Polar Beat and Polar Flow to monitor your heart rate during the workout (without monitoring your heart rate it is hard to do zone training).
Check it out: