They're more than a fashion statement. John Stringer looks at the history and technology of trainers.
When Phil Knight founded Nike in 1971, Adidas and Puma were already 50 years old. Adi Dassler and his brother Rudolf began making sports shoes in Germany in the 1920s. But after the Second World War, they split up. Adi formed the Adidas company and Rudolf formed Puma. They have been business rivals ever since, along with Nike, Reebok, LA Gear, Hi-tech, British Knights and many others.
However, the modern training shoe was a product of 1960s' fashions, when boots and shoes were first made from synthetic materials, and technological advances influenced footwear design. Trainers and sports shoes suggest you have a leisure base to your life.
A good sports shoe can protect your foot and leg. If you run a marathon, your foot will hit the ground more than 25,000 times, with a force two to three times your body weight.
When running, your foot strikes the ground heel first. It sags flat to the ground as your body passes over it. Your knee bends slightly to cushion the blow, and the other foot reaches forward. Now the foot rotates until only the toe is in contact with the ground, and you push off from this toe into the next stride, transferring your weight to the other foot.
Trainer design can include: lightweight nylon side panels which allow air to circulate; a mid-sole support of nylon or a tough plastic material which cushions the foot and stops it from moving within the shoe; a hard-wearing carbonrubber sole, grooved to flex with the foot, which improves the grip; sometimes the soles are cushioned with several gas bags, each containing a dense gas in a flexible plastic skin, and air cushions at the heel and the ball of the foot to absorb most of the impact.
Adidas has recently launched a running shoe which enables runners to use their energy more efficiently through a special bouncing effect. Another shoe keeps feet 20 per cent cooler and drier by reducing sweating.
Competition in the industry is very strong, and so Adidas has decided to look at two new niches for future growth, focusing respectively on history and heritage, and on fashion. There are trainers that reproduce retro designs, such as the Italia, a shoe based on the footwear of athletes in the 1960 Rome Olympic games. Others revive the design of skiing boots from 50 years ago. Another development is a new sports shoe, designed to be worn with a suit.
The past 100 years saw a staggering change in the number and type of shoes available for everyone, reflecting changes in lifestyle. The most popular woman's shoe when Dassler senior launched his sports shoe in the 1920s was a bar shoe with a strap and button, ideal with short skirts and for dancing. Between the wars, the high-heeled shoes worn by screen stars like Jane Russell were popular with women, while men wore two-tone Oxfords.
Roger Vivier is credited with inventing the stiletto heel in the 1950s, when young men were wearing crepe platform soles or elongated winkle-pickers. The platform shoe was revived for women in the 1960s.
Today, there are shoes for every kind of work or leisure pursuit.
Traditional work wear has inspired heavy-soled boots like Doc Martens, but the sports shoe has stayed in fashion and seems likely to become a classic.
Bring in an old trainer you have sawn in half lengthways and ask children to identify the component parts.
Design a trainer for a particular customer.
Explore the grip of different trainers by putting them on a plank and then slowly lifting the end of the plank to see which one slips first. Ask children to imagine starting a race on sheet ice.
John Stringer is a teacher, in-service provider and author