Have you ever found yourself exercising, maybe up to 3 times a week, and getting frustrated because it seems to make no difference? Exercise is critical to change your metabolism and lose weight - but you may need to exercise in the 'zone' to lose weight. You should be exercising at a high intensity and sweating profusely, if you are not, it may assist your fitness levels, but may not help you lose weight. This is why you may see hikers who are overweight, but you are unlikely to see a fat runner.

So how do you know if you are exercising in the zone? You need to make sure you are exercising at 70-80% of your maximum heart rate. We showed you how to take your pulse in the feature on testing fitness. This is your heart rate. Take your heart rate whilst you are exercising to find out if your exercising in the zone. There is a calculation to find your zone heart rate targets.

Don't get us wrong, any exercise is good for you, but if you want to lose weight you should try to exercise in the zone. If you exercise below your zone minimum heart rate, you may maintain fitness levels and weight, but those pounds may not disappear. You should be aiming to work somewhere between your zone minimum and maximum heart rates for no less than 20 minutes. If you are a beginner to exercise, this will probably take a little time. Try working out at a lower level, but then increasing the intensity for short periods of time. Persevere, and not only will you be amazed at how quickly you get to stay in the zone for 20 minutes, you will also be amazed at the visible results.

So how does the zone feel? When you are exercising in the zone you will be breathing deeply, sweating and feeling tired. You will be able to speak, but you will probably not feel like talking. There may be a feeling that you will not be able to finish the exercise session without pushing yourself. Once you have taken your heart rate a few times and found out how the zone feels for you, you will soon know when you are there! Let us know how you get on!