Are trendy trainers worth it?

Hip French designer Philippe Starck has teamed up with sportswear manufacturer Puma to produce a range of sleek and stylish trainers. Due to be launched in the autumn, the new footwear collection is guaranteed to become an instant hit with the fitterati - those gym members who like to combine working out with cutting-edge fashion.

With the market for trainers expanding every year - 4.5 million pairs were bought in the UK in 2003 - manufacturers are constantly battling to gain an edge over their rivals. Millions are spent on researching, testing and constructing increasingly high-tech shoes with spage-age features such as "memory" foam springs, and any number of mechanical additions that cushion and protect the foot.

But some experts are warning that, while designer trainers might be good for your image, they could damage your feet, knees and back.

So do the space-age design features make a difference? I am training for this year's Flora London Marathon so decided to test the latest designer running trainers to see how good they really are ...

Nike Mayfly(£25, 0800 0561640)

Sci-fi selling points: the mayfly is an insect that lives, breeds and dies in one day. This, the first disposable running shoe, doesn't have quite as short a lifespan, but it is designed to be worn for no more than 100km (60 miles) - the distance many club runners would cover in a week. After that, you throw the shoe away, although you will soon be able to send it back to a recycling centre at the company's headquarters.

The Mayfly weighs just 135g, which may help your running - according to research, for every 100g you carry on your feet, you expend an extra one per cent in energy to run at the same speed.

Verdict: because they are so lightweight there is virtually no support for the foot. Unless you are one of life's skinny racing machines who runs like the wind, avoid the Mayfly at all costs.

Adidas a3 (£100, 0870 2404204)

Sci-fi selling points: instead of the usual solid foam, this shoe's heel unit comprises four angular pillars, made of tough polyurethane, which provide cushioning as you run and prevent the foot from rolling inwards or outwards.

They are attached to a "hermoplastic transition plate" which absorbs shock and propels the foot forward so that, in theory, you run faster. Analysis by Adidas suggests the a3 provides up to 20 per cent more stability and retains its bouncy cushioning 35 per cent more effectively than rival trainers, even after 600 miles of running.

Verdict: they are light and you do feel as if you are running faster in them, although podiatrist Trevor Prior, who works with leading athletes, says this is almost certainly not the case. Still, they are among the most comfortable of all the shoes tested.

Nike Shox FSM (£95, 0800 0561640)

Sci-fi selling points: Nike's biomechanic specialists have come up with a design that features four bouncy columns in the heel of the shoe - the culmination of 16 years' research. Because of this suspension system, the Shox decrease stress on the ankles and reduce the risk of injury. FSM stands for "foot strike management", a system of shock absorbing plates in the sole which help to keep the foot stable.

Verdict: Trevor Prior was unimpressed. "They offer very little support and control to the foot," he says. "If you are a heavy runner this could mean that you risk compression of the Achilles tendon when your foot rolls inwards or outwards as you land." I found the heel excessively wide which forced me to change my running style.

Reebok Premier Stability (£70, 0800 305050)

Sci-fi selling points: Reebok's footwear engineers analysed films of thousands of runners and noticed that, in many cases, their heels tended to slip slightly forward, which meant their feet were prone to rolling inwards or outwards. To rectify this the Stability features a soft strip of polyurethane in the midsole which acts as a sort of brake. Cushioning comes in the form of Reebok's DMX system, a foam that offers protection from the heel through to the toes and helps conserve energy.

Verdict: these are significantly heavier than other shoes (more than 400g). But they do feel sturdy and supportive and, after a couple of runs, start to lose their inflexibility. Plenty of traction on the soles and lots of reflective strips which mean they are good for what remains of the cold, winter nights.

Asics Gel Kayano (£110, 01925 817009)

Sci-fi selling points: Asics' biomechanic experts in Japan have included "biomorphic fit" panels into the lightweight, sweatwicking mesh upper, which can help runners avoid blisters. Rather than the springs in the sole adopted by Nike and Adidas, Asics uses its own trademarked Gel to provide shock absorption and cushioning. The removable insole controls moisture and odour, and the heel is made of "memory" foam that shapes itself around the foot.

Verdict: Expensive, but beats the others by a four-minute mile and, as someone who has been running for 22 years, I would stick my neck out and say it is the best shoe I have ever worn. It may not look very space-age, but in terms of scientific advancements the Gel Kayano is streets ahead.