Years ago, people marvelled at a simple speak-your-weight machine.

Now there is a contraption capable of performing many more computations.

Boditrax sends a pulse of electricity through your body to reveal your true metabolic age.

Swallows Leisure Centre in Sittingbourne has had one for a while but now a £7,000 terminal has been installed at Sheppey Leisure Centre in Sheerness. So it seemed fitting to give it a work-out.

As someone who has just celebrated his 69th birthday, I volunteered to put the machine through its paces.

All gym members get a go on the Boditrax scanner and can then track their progress on an app providing they don't have a pacemaker or are pregnant.

All you have to do is type in your name, age and height, slip your socks and shoes off and step onto four metal electrodes. Within 30 seconds it works out your water content, bone density, muscle strength, fat mass, cellular density, overall physical score and body mass index for a full MOT.

Dave Harcourt, the chief executive officer of Swale Community Leisure which runs the gyms for the council.

He said: “It works as a motivational tool. People can see how their work in the gym or the changes in their diet are paying off. Some numbers go down and some go up but these readings are an accurate representation of what’s happening inside customers’ bodies.

“The level of detail this machine is able to provide in just 30 seconds is quite staggering and it’s all free with one of our gym memberships.

"Any of our customers who have not tried it yet should ask the gym team or reception and they will sign you in, giving you the chance to set goals, track progress and maybe see your metabolic age go down a year or two.”

Rolling 30-day gym and swim memberships cost £31.50 a month or £25.90 a month if you sign up for a year. You can pay a year in advance for £259.50 and get two months free. For details, visit here.

The machine, by the way, decided I had a the body of a 54-year-old man. I was pretty impressed with that but it appears the chap now wants it back!