YES, judgement day has arrived. It's the final countdown, the moment of truth. Have I used my six week stint at Teddington Pool and Fitness Centre to its full potential? Or have I been secretly sloping off down the pub every night?

My final meeting with instructor Alex Wolf consists of a fitness assessment, identical to one we completed before I embarked on my gym programme. The test involves 15 minutes on the exercise bike, with the level of intensity increasing at certain stages. Recordings are made of my heart rate before, during and after the exercise - the idea being that this time my results show improvement.

I felt slightly apprehensive when I arrived; I was being tested but there was no last minute cramming I could do, I just had to trust that work over the last few weeks had paid off. But mostly I was extremely curious - could there be a noticeable difference after six weeks?

Like many women, I am no stranger to visiting the scales to keep a watchful eye on my weight, but my heart rate is not something I've really considered. At Teddington gym a small electronic machine is attached to me and I have no idea how it works, but it's fascinating. You watch the number of heart beats per minute go and up down according to what you're doing. If you stand up it increases, or if you speak it moves slightly - because even talking requires your heart to work harder.

The following table records my heart rate (HR) throughout the assessment, before and after the six weeks. It also shows a rate of perceived exertion (RPE) - which are numbers I was asked to indicate on a scale of how hard I was finding the exercise, five being very light and 20 being extremely hard.

Hopefully you can make sense of the table and witness that after six weeks my heart did not have to work as hard when put through the same level of exertion. In other words - I am now fitter. Hooray! And the RPE column shows that I could feel myself working less hard.

Alex says a good fitness indicator is how quickly your heart returns to normal (to your resting heart rate) and the table shows mine recovering significantly faster in the final test.

I was particularly pleased to have also lost 6lb in weight. But Alex warns that weight isn't always a reliable indication of how effect your fitness regime is; you could be toning up and turning muscle to fat, but it won't necessarily show on the scales.

Muscle apparently weighs three times more than fat - hence body builders and athletes are surprisingly heavy. This is fantastic news. If I put on any weight in the future it will obviously be down to my new bulging biceps rather than that extra helping of double chocolate fudge cake.

But it's interesting to think that we are so concerned with every pound lost or gained but rarely pay attention to our heart rate or blood pressure - unless forced to for health reasons. There's been great concern recently over the nation's obesity levels and the government is even considering a tax on fatty foods. But would such drastic measures be necessary if everyone took enough exercise?

I've managed to visit the sports centre three times a week and have generally felt healthier and happier. I've been less tired, had more energy and notice I sleep better after exercising. So these six weeks have proved to be about much more than just losing weight.

I shall certainly be making it a permanent feature in my life and have decided to sign up as a member at Teddington because it has everything I need for a reasonable price. Full membership - unlimited gym, classes and swimming - is £39 a month and there are cheaper options, including pay as go' visits with no long term commitment.

At the risk of sounding like my Grandma, the problem we face today is having lifestyles that lack physical activity. Jobs used to be more physical and kids walked to school and ran about outside rather than playing on computers. Ahh, the good old days - we've heard it all before, but probably because it's true. Times have changed, so when we leave our desk at the end of the day we should be getting our big, lazy behinds down to our local sports centres.

So what are you waiting for? If I can do it, so can you.