People have been bouncing for many hundreds of years. It's said the Inuits would toss each other in the air on a walrus skin. And ?blanketing? - an impromptu punishment involving being thrown in the air by a mob - is recorded by Cervantes in Don Quixote. But it was in the circus that performers first used a device to increase their jumping ability. An 1843 circus poster was quoted by the Beatles in their song ?For the Benefit of Mr Kite? on the Sergeant Pepper album:



?For the benefit of Mr Kite there will be a show tonight on trampoline??

But it's thought that this trampoline was more like a springboard than the apparatus we know today.

For all intents and purposes though, the trampoline as we recognise it comes from two gymnasts based at the University of Iowa in the USA. George Nissen and Larry Griswold saw how trapeze artists increased the impact of their dismounts by stretching their safety net. In about 1934, they built the first modern trampoline after experimenting with tightly-stretched canvas, linked to an angle-iron frame with springs. They went on to patent the invention and can be considered the fathers of the modern trampoline.

But while the genesis of the trampoline is well detailed, there's argument over the derivation of the name. Nissen and Griswold initially called their invention the ?rebound tumbler?. And according to circus historians, the word ?trampoline? comes from a performer called du Trampolin. There is though little evidence for this. More likely, the trampoline as we know it derives from a remark overheard by George Nissen during a demonstration tour (as one of ?The Three Leonardos?) in Mexico. El trampolin in Spanish means diving board. (A similar word in Italian - trampoli - means stilts.) Nissen decided to use the word, slightly altered, as the trademark for his device and it's since become the generic term.

During the Second World War, the US Navy recognised the cost benefits of being able to instruct pilots and navigators in spatial awareness while still on the ground and it became common for trampolines to be used in training. The practice continued after the war, when US astronauts and Soviet cosmonauts were taught the use of different body attitudes in flight.

With its usual thoroughness (and then almost limitless budgets), NASA commissioned scientific research at the end of the 1970s into the physical benefits of trampolining, which was published in the Journal of Applied Physiology in 1980. The authors took eight fit young men and measured how their bodies responded on the one hand to jogging on a treadmill and, on the other, to bouncing on a trampoline. Their findings were spectacular; and they've become the basis of all the health-benefit claims ever since.

According to their research, for similar levels of heart rate and oxygen consumption, ?the magnitude of the bio-mechanical stimuli is greater with jumping on a rebounder trampoline than with running,? a dry statement that masks their conclusion that trampolining exercised their subjects up to 68% more than simply jogging. That's a massive difference, and in some cases they found that bouncing was more than twice as efficient as running on the treadmill.

And there was more. Runners are prone to injuries to shins and knees caused by repeated jarring. But bouncing on a trampoline caused no undue pressure on legs, ankles or feet. So trampolining was not only more efficient than running - it was safer too.

Those researchers recommended trampolining as a way of rehabilitating astronauts returning from a weightless environment. But for those of us who haven't been in space, subsequent research has thrown up even more physical benefits, most notably for the body's lymphatic system, which looks after our immunity from disease by getting rid of toxins and returning proteins to our blood.

The lymph system relies on muscle contraction and breathing to generate a flow round the body and controls it through a one-way valve mechanism. When you bounce on a trampoline, the valves close on the way up and open on the way down. At the top of the bounce, gravity is zero and you become weightless. As you descend, the G-force doubles over the ordinary effect of gravity and this action alone can stimulate the lymph system to increase its activity by up to 30 times its normal level. A trampolining session could therefore be as good for you as any ?de-tox? diet, if not better.

In fact, medical and sports physiotherapists have come to rely on the trampoline for a variety of benefits to their patients. In addition to the impact on concentration and awareness found by the US Navy and the aerobic effects discovered by NASA, trampolining strengthens the limbs, improves balance, co-ordination and reaction speed, heightens muscle tone and increases stamina. And it's fun!

Trampolines are increasingly being used to help people with physical or mental disabilities. It's been shown that trampolining improves patience, communication, self-confidence, social awareness, perception of height and independence.

And some researchers have claimed improvements to the digestion, in preventing some forms of arthritis and osteoporosis and as an ideal way of treating chronic fatigue syndrome (or ME).

Trampolining has been a competitive sport since just after the Second World War and its importance was recognised with its entry into the Olympic Games at Sydney in 2000. Eight years later its progenitor George Nissen, then aged 94, travelled to Beijing to watch the competition taking place. And 70 years after he came up with it, he could be forgiven for thinking his ?rebound tumbler? had taken its place as a significant contribution to the well-being of the world.

But one of the most important effects of trampolining is perhaps the least surprising. Like any exercise, a good session on a trampoline will help you burn calories. But because trampolining is such fun, many believe it could be the answer to the growing problem of child obesity. Try and get your overweight 12-year-old away from their games console to go on a cross-country run and you're inviting trouble. But get them on a garden trampoline and it's a different proposition altogether!