Time was the most important thing about shoes was that they were comfortable and did not give you blisters. However the manufacturers of the latest generation of training shoes make much grander claims. They claim the shoes can tone you up, get rid of cellulite and help you lose weight.
The choice of styles has also increased. Companies such as Reebok have stuck to the trainer design introducing an Easytone range with "balance pods with moving air" - which force you to work harder for your balance, thus strengthening your legs - or that is the theory
However, there are different models for the gym, to go running in or for casual wear. MBT has introduced an extensive range of trainers and shoes that include designer style boots. Expect to pay £150 for its athletic range, and anywhere up to £299 for their trendy leather knee high boots. As they are clearly more expensive than everyday trainers do they warrant the larger investment?
Mike O'Neill a podiatrist and spokesperson for the College of Podiatrists ,feels that a lot of tone up training shoes on the market are overpriced, and will not replace a good workout in the gym. "A lot of them are very gimmicky," he says, "and you have to take their claims with a pinch of salt".
Hector Wells, a registered osteopath with a special interest in foot mechanics and injuries, has been on a training course run by MBT.
"There are a number of rules we have to understand" he says. Wobble boards, on which they have based their design, have been an intrinsic part of rehabilitation for a long time. He emphasises that it is important not to wear this type of shoe all day at first, perhaps initially for about 40 minutes to an hour at a time. He sees them as a good investment for those aged 70 plus, or anyone who has a problem with their balance
The consensus of opinion is that the shoes improve balance, and thereby increase range of mobility. Because the shoes have a reverse contour, they initially create a feeling of instability in the brain, which makes anyone wearing them work harder to improve their balance. My experience is that I initially felt unstable, but this resolved itself once I got used to them.
"Shoes like those made by Skechers and MBT can help someone if they have pain in their big toe joints, ankles, and knees," says O'Neill. "They cause us to stand differently and this affects our body posture."
Promises that we can lose weight by wearing tone-up type shoes is a hype that has been universally rubbished. The bottom line is that you are unlikely to lose weight without sustained exercise. "Buying more costly trainers in the hope that they will provide us with a greater benefit is a fallacy," says Wells. However, the perception of improvement could very well make us feel better.
Sammy Margo, a chartered physiotherapist who practises in north-west London, wears tone-up shoes a lot. She finds them more challenging than normal footwear, and says they add a new dimension to a workout.
She stresses that this type of shoe is not suitable for everyone, and that it is important to have proper instruction on how they should be worn. "Many people don't know how to walk properly," she says, which is why the incidence of back pain has gone up. The shoes, she feels are part of the bigger picture in helping people to walk better.
"People might not be aware that they can injure themselves if they don't wear them properly."
Foot Solutions, an American franchise which is mushrooming in the UK, uses high-tech foot scanning equipment to provide a gait analysis and test for pressure points on the feet of their customers.
Karen Scowcroft, the owner of the Plymouth franchise, herself a state-registered podiatrist, finds that people come in wanting a particular brand. "We may have to steer them towards a make that is more suitable", she says.
"They like the cushioning effect that toning shoes provide. They are easy to wear."
But she warns that MBTs, which she calls "a medical device", need professional fitting.
With so much choice, and a huge range of prices, it is definitely worth taking advice. If you have no qualified person to guide you, seek out a reputable sports shop or a trusted retailer.