Despite the hazards, more people are getting hooked on extreme sports. Rosita Boland meets some people who feel the need for speed

Sport is a marvellously elastic term that covers everything from the Olympic-featured bejewelled heads of the synchronised swimmers, to looping the loop in small planes as a stunt pilot. While all sport operates on a degree of adrenaline, it's fair to say that your life is rather more at immediate risk when doing solo tricks in a tiny plane, rather than swimming with team-members in a pool with a clothes-peg on your nose.

Last month, Swedish aerobatic champion Gabor Varga was killed while performing complicated manoeuvres at an air show in Malta. He had once performed 256 loops in one hour - an astonishing display of continuous aerobatics at the rate of more than four loops a minute. His plane collided accidentally in mid-air with one piloted by Irish dentist Eddie Goggins, and fell into the sea with its tail sliced off. Varga, though rescued from the water, died soon after of his injuries. Amazingly, Goggins parachuted uninjured to safety.

Last month also, Richard Hammond, one of the presenters of BBC's car programme Top Gear, was seriously injured while test-driving a jet-powered dragster car in Yorkshire. He suffered brain injuries when it crashed doing a speed in excess of 300mph (482kmh), and he remains in hospital.

These are just two extreme and dangerous sports, but there are others, which attract many followers. One of them is motorbike road racing, which takes place at high speed on closed public roads. Dubliner Martin Finnegan, who has been racing for six years, is the fastest Irishman ever to compete the gruelling Isle of Man TT Motor Cycle Race. This race is a time trial against the clock, over six laps totalling 37½ miles - it is the Grand National of bike racing.

More than 100 people have been killed while competing in this race, which takes place on a day that is nicknamed "Mad Sunday". Finnegan gained his Irish record last summer.

"It's a worrying sport," he admits reluctantly. "I have a partner and a child and they naturally worry about me.

" It's not enough to put him off, even though every year sees fatalities in the sport. He's known three people who have been killed in competition, but he doesn't like acknowledging this fact or dwelling on it. "At the end of the day, it's something you have to put out of your mind, and just get on with it."

Finnegan rides a 160 kg bike, with an engine capacity of 1000cc - "a super-bike". He thinks that to be a good racer, you need to ignore the dangers involved, and to focus on racing. Knowing how the mechanics of the bike work is also essential, so that you understand the hulk of machine you're racing.

Why does he do it? "The adrenaline rush," he explains simply. "Once you've done it once, you want that buzz again."

Has he ever been frightened? There's a short silence, and then a tiny sigh, followed by a firm "No".

If the latent danger of machines is that they can let you down mechanically, no matter how skilled you may be at handling them, when it comes to horses, their danger is obvious - their size. "We all wear the safety equipment - helmets, back protectors - but nothing can protect your neck or body if half a ton of horse lands on top of you," says professional rider Susan Shortt.

Shortt, who is based in Kilcullen, Co Kildare, has been riding horses all her life, and specialises in three-day eventing, for which she has twice represented Ireland in the Olympics. This competition encompasses three separate tests: dressage, a formal series of commands which the horse must obey; cross-country jumping; and show jumping. It's the cross-country jumping that is the riskiest element. "You're jumping big, solid jumps on a big course - logs, ditches, banks, jumping down into deep drops. You have a certain amount of time to complete the course, so you're always going at speed."

The worst thing that can happen an eventer while cross-country jumping is a rotational fall. This is where the rider is pitched forwards at a jump, and when the horse then somersaults over the jump, and lands on the rider. Terrible crush injuries can ensue. They are the relatively lucky ones. Many others die, literally crushed to death. "All the precision and horsemanship sometimes can't save you from a mistake."

Three of Shortt's friends have been killed while eventing, all suffering rotational falls. The latest of these to die was Northern Irish rider Sherelle Duke (28), whose horse fell on top of her in August.

"I'd be telling you a lie if I didn't tell you I was scared sometimes. But in our game, if you go out expecting a fall, you'll get one. And fear creates adrenaline. Part of the attraction is the danger element, but when you're out there riding the course, you don't think of anything except the thrill of the horse responding to you.

"I love eventing. It's addictive - the whole thing of training half a ton of animal to do ballet-like things in the ring, to be careful in show-jumping and brave and courageous in cross-country jumping. The sheer adrenaline of the cross-country jumping is what keeps most eventers at the sport."

Kite-surfing is a fairly new sport to Ireland, and has been going for less than a decade as a worldwide phenomena. Shane O'Brien, from Skerries, Co Dublin, has been doing it for some years now, usually on Rush beach with a crowd of friends. "It's a mixture of several sports," he explains. "It's a bit of windsurfing mixed with weightboarding."

Kite-surfers stand on a board, which is strapped to their feet, and wait for a kite attached to the harness around their waist to be launched. The launching is usually done by someone else, and kite-surfing is best done with others - although a great deal of skill is involved to make sure some 20 kite-lines don't get tangled up with your fellow surfers. The bigger the wind, the smaller the kite you use (O'Brien has four kites, of varying sizes). "Unless you have a death wish, you wouldn't launch a big kite into an offshore wind - you'd end up somewhere off the Isle of Man."

The main buzz of kite-surfing is to jump, buoyed up by your wind-filled kite, 25m above you. "You can travel half the length of a football pitch before you land again." It's not possible to get up in less than 20km of wind, but skilled kite-surfers can manage winds up to gale force seven.

"The better you get, the better and higher and longer you can jump." They are required to be out 200 metres from the shore and to give way to swimmers and small craft - and each other. "One of the dangers is watching out you don't get tangled up in someone else's line."

The chief danger, however, and the result of several fatalities worldwide, is of being dragged by wind when airborne, then landing on rocks. "Obviously, you check the weather before you go out, but you can't account for gusts, and then being carried in on an on-shore wind."

A couple of years ago, O'Brien jumped 20 feet in the air. He was caught by a gust at that height, and blown higher - and backwards, toward the beach. "When I started jumping, I was in deep water, and when I landed, I hit a sandbank." Luckily, he was not badly hurt, and he was back kite-surfing within a fortnight. "It's the buzz. There's nothing like it."