Stuttgart - Many joggers dream of running a marathon some day. Although a full marathon is 42 kilometres in length, that does not prevent even the most inexperienced athlete from at least considering taking part in one.

All budding marathon runners should train aplenty in spring as even experienced joggers will find a marathon challenging.

People over the age of 35 or anyone who smokes should let their GP check them out before beginning training, advises Professor Hans-Hermann Dickhut, director of the Sport Medicine Institute at the University of Freiburg.

Orthopaedic issues such as problems with the knee, hip joints or spinal column should be closely looked at. The body's cardiovascular system should also be in good shape before attempting training and the shoe cupboard should contain at least two pairs of training shoes, said Michael Gruening, deputy editor-in-chief of the Stuttgart-based Runner's World magazine, and someone who has completed 112 marathons.

"By alternating your trainers, you avoid overexerting one side of your skeleton and injuries."

A marathon runner needs between three and four months preparation, according to Dickhut. That means a typical weekly training programme should consist of between 30 and 40 kilometres running. Anything less than will not make you fit enough for a marathon.

Another important issue to take into consideration is overall fitness.

"A training programme of between 10 and 12 weeks is only suitable for someone who has at least one and a half years experience jogging," says Herbert Steffny.

Steffny, from south-west Germany, has been holding seminars on how to jog for 20 years.

A slow training pace is an important factor as it helps to get the body's tendons, bones and joints used to the strain of regular jogging.

"A properly paced training session allows you to talk at the same time with your partner."

Most coaches and sport physiologists agree that long training programmes are the key to success, Gruening says.

As you jog, the body converts carbohydrates in the form of glycogens into energy. As soon as the body uses up its reserve of glycogens, it starts burning fat to release energy but it can only do so during a slow jog.

"That explains why it is usually during the second half of a marathon that runners collapse," says Gruening.

By gradually jogging for longer distances, the body learns to build up bigger reserves and streamline the release of energy. Without completing at least the required minimum of long-distance training, you will never arrive at the marathon's finishing line.

"We're talking here of at least six runs over 25 kilometres," says Gruening.

The final, long distance training session should be no later than two weeks before the marathon. Taking part in shorter competitions can help you build up mental discipline and perfect your tactical skills.

"Beginners would otherwise get nervous on the big day and start running too quickly," warns Steffny.

The slower your build-up to the long distance training sessions, the more likely you are to succeed. (dpa)