Costume change: They were professional swimmers' secret weapon so why have 'supersuits' been banned?

When Mark Spitz won seven golds at the 1972 Olympics, his star-spangled nylon briefs were required only to preserve his modesty. Today, space-age swimsuits have made such a splash an entire sport is struggling to preserve its integrity.

The solution: a return to the Spitz era. Fina, swimming's governing body, has banned hi-tech plastics and, from next year, swimmers will revert to traditional trunks. Good news for critics of so-called "supersuits", but what do the innovators who have put so much at stake think?

Francesco Fabbrica has spent two years and a small fortune creating and perfecting what must now be the most controversial garment on the planet. The Jaked 01, named after Fabbrica's sons, Giacomo and Edoardo, has been more successful than the Italian could ever have dreamed. His logo has sprung from nowhere to swim with the biggest fish in the pool – Adidas, Speedo, Arena – and athletes have broken dozens of world records in his suits. But now he must go back to the drawing board.

"We don't think it will be positive to go back to the old technologies," says Fabbrica. "But we will accept the new regulations." It's a diplomatic reaction, but Fabbrica was more outspoken in when Fina first tried to ban his suit in May (it then lifted the ban before making its final decision). "As a man, I'm dismayed," he said. "As the boss of a company, I'm shaking with anger."

If anything, Fabbrica's crime was to be too good. Take Frederick Bousquet as an example. Back at his national championships in April, the French sprinter shaved more than half a second off the world record in the 50 metres freestyle. As the first man to go under 21secs in the event, he became the fastest swimmer on the planet. But the only topic of conversation following his stunning performance was that, before donning his Jaked 01 suit, Bousquet had never qualified for an Olympic final.

Bousquet's is just one in a tidal wave of recent records to have been blown out of the water in recent months, and the Jaked is not the only suit now deemed too fast for swimming. Speedo's LZR, which helped 79 swimmers to break world records last year, will also join the Adidas Hydrofoil and the Arena X-Glide on the Fina blacklist. So what makes them so effective?

Doctor Herve Morvan is a professor in fluid mechanics working for Speedo's Nottingham-based Aqualab. "When you are travelling through water you fight against drag caused by friction and form," he explains. "The LZR has components which will help reduce drag by shaping your body so it is more streamlined. Panels of composite polyurethane reduce friction in the areas where our research shows it is highest. The suit also helps the body into an optimal swimming position."

Morvan points out the differences between the LZR, which is 50 per cent polyurethane, and the fully polyurethane competition. "Because the newer suits are impermeable, they can trap air and increase buoyancy, which is important because swimmers don't have to use as much energy to stay near the surface, where friction is lower."

Fabbrica insists the Jaked does not boost buoyancy, but the overall effect of the new suits is impossible to deny. Swimmers, naturally, have been keen to play down their effect, but the assessment of Britta Steffen, a German swimmer who broke the 100 metres freestyle record in the Adidas Hydrofoil, was telling. "I felt like a speedboat," she said. "I would never have thought a human could glide like that."

Morvan, like Fabbrica, is diplomatic in the wake of Fina's ruling, but Speedo reacted strongly to its inclusion in Fina's ban. The company said in a statement earlier this week: "Any move which seems to take the sport back two decades ... is a retrograde step that could be detrimental to the future of swimming."

Some have compared the Fina ban to the outlawing of carbon fibre bikes or a return to wooden tennis rackets, but there is a sense in the swimming world that the sport has a purity that is worth preserving. "Swimming is beautifully objective," explained Duncan Goodhew, who won a gold medal at the 1980 Olympics, in an interview with the BBC in February. "The integrity of the sport is man in water, so the swimsuit should be neutral."

Goodhew isn't the only man who'll be relieved to see the back of the supersuit. Michael Phelps was thrashed by Paul Biedermann in the 200 metres freestyle on Tuesday. Phelps wore his trusty Speedo suit but Biedermann sported an Arena X-Glide. "I look forward to racing him next summer," Phelps told reporters after his first defeat in the event in five years. "It will be fun when swimming gets back to swimming."