Enthusiasts say that not only is cycling good for your health - it is good for the environment too.

But some people may take issue with the health claims.

According to the Royal Society for the Prevention of Accidents in 1996 3,785 cyclists were either killed or seriously injured in cycling accidents in the UK and a total of 24,534 accidents involving cyclists were reported in that year.

'Hit by a cement-mixer'

Cycling: good for your health?

Cyclists can dice with death every time they put foot to pedal, especially in cities. In London last year 562 cyclists were seriously injured in road accidents and 12 actually died.

If the heavy traffic and careless drivers don't get you, then you face being choked to death by exhaust fumes. Experts link rising pollution levels to the increase in the number of people suffering from asthma and the volume of road traffic in the UK is predicted to increase by over 80% in the next 25 years.

Paul Heseltine, a computer programmer, who has been cycling in London for over 20 years has had a catalogue of close calls.

"I've been hit by a cement mixer ... I've run into about two or three car doors which have just been opened in front of me. I was even beaten up by somebody who actually ran into me ... But I don't seem to have as many accidents as I used to, maybe I am becoming just a little bit more careful or maybe I am just slowing up a little bit. "

His advice for wary cyclists is "to just keep your eyes open".

'I grabbed hold of his aerial'

Holly North, a keen cyclist who rides to work every morning in London has also had a few run-ins with road pests. She advises a more aggressive approach.

"This man was really abusive and tried to drive into me as he overtook me. He kept hooting and I gave him the finger.

"So then I grabbed hold of his back aerial and he pulled me along for a while and then it came off and I threw it in a bin.

"He tried to chase me, but of course he couldn't go on pavements."

But she says that London is no worse than anywhere else.

"You have to make sure you are aware of what's going on in the road. If you really enjoy cycling and you are aware that everyone is out to kill you, you should be fine."

'Nice one' - BMX bikes were first popular with children in the early 80s

Liam Corner who rides a trendy 'Fat Boy' BMX bike around the capital says that he gets an altogether different reaction from motorists.

"I often get people pulling up and driving along side of me and asking me 'where did you get that?' Brickies and builders normally call out 'Nice one mate' when I go past."

'Not as bad as you think'

Sue Brown from the London Cycling Campaign agrees that cycling in a city can be a little worrying if you are inexperienced but says, "it is not as bad as people think."

Sue Brown, London Cycling Campaign: It looks worse than it is

"One of the things that puts people off most of all is they think that cycling to work is a good idea _then they cycle along the obvious main roads and have a horrible time."

She advises that anyone who has never cycled in heavy traffic before but is keen to go green should speak to experienced cyclists and plan a route.

Wearing a protective helmet is a good idea too, but she said:"You will get far more protection by making sure you know what you are doing before you set off."

In London a cycle network is currently being built throughout the city and the cycling campaign can provide a map and advice of good routes to take.

The government gears up

National Bike Week is also backed by the government which is currently developing an "integrated transport policy" to encourage greener travel.

Glenda Jackson, the Minister for Local Transport said: "National Bike Week creates a strong focus for promoting the value of cycling. We need to demonstrate to a wide range of people how cycle use can be relevant to them."

Doing just that on Tuesday will be over 100 MPs, including Tony Banks, Michael Meacher and John Gummer.

They will be testing out the capital's streets in what has been named "The Great Parliamentary Bike Ride". The MPs, many of whom are part of parliament's All-Party Cycling Group, hope to encourage greater use of the humble bicycle.