Bicycle motocross (or BMX, as it is more commonly known) started in California in the late 1960s, not long after motorcycle motocross had become a popular sport in the United States. BMX was a pastime that was originally popularised by children and teenagers who possessed the desire, but not necessarily the financial wherewithal, to participate in motorcycle motocross. In the seeming blink of an eye, thousands of children were to be seen racing through the California dirt, trying to emulate their motocross heroes.

The International BMX Federation was founded in 1981 and the first world championships were held in the following year. BMX was fully integrated into the International Cycling Union, cycling’s governing body, in 1993.

On 29 June 2003, the International Olympic Committee decided to include BMX in the 2008 Beijing Games. Maris Strombergs, of Latvia, was triumphant in the men’s event in China while Anne-Caroline Chausson claimed victory in the women’s competition. Overall, USA won three of the six medals and France two.

BMX races, which include up to eight riders, are normally held on circuits that measure between 300m and 400m in length and include banks, jumps and other obstacles. Most events are held outdoors on permanent tracks. It is a type of cycling that takes place on specially designed bicycles that characteristically have 16 to 24-inch wheels. The norm is 20 inches.

Depending on the length of the course and the degree of technical difficulty, a BMX race typically lasts between 30 and 40 seconds.

The best BMX riders possess a mixture of exceptional body strength, excellent motor co-ordination skills, strong technical ability and a shrewd tactical brain.

More BMX bikes are now sold in the USA than any other type of bike.

Elbow pads, knee pads and shoulder pads are not essential for BMX cycling, but they are highly recommended.

Through federations that are officially affiliated to the sport’s governing body, there are now more than 60,000 BMX riders worldwide who hold a racing licence.

Mountain-biking cross-country is generally considered to have evolved in mid-20th century France. Cyclo-cross was contested in the winter months as an off-season training method for professional cyclists. It consisted of riding over unforgiving terrain, with the participants often having to dismount when they encountered particularly rough areas.

A new form of bicycle racing began to develop in California in the 1970s. It was similar to cyclo-cross, though with fatter tyres and a suspension system. The first national mountain-biking cross-country championships were held in the United States in 1983 and the first world championships were contested in 1987.

Mountain-biking cross-country events, for both men and women, were introduced to the Olympics in 1996, with the men’s race covering between 40 and 50 kilometres and the women’s 30 to 40 kilometres. The participants compete over a course that is normally hilly and includes rocks and streams that have to be negotiated.

Of the 24 Olympic cross-country medals that have been won so far, 21 have been claimed by European countries. France have carried off the most gold medals (three) while Italy have won two and the Netherlands, Norway and Germany one apiece. Great Britain, alas, have yet to win a medal of any colour.