As feats of sporting endurance go, they don't come much tougher than the Tour de France.
Held every year over three weeks in July, the world's best-known cycle race has become increasingly popular in the UK over the past decade, bolstered by daily TV coverage, British rider successes and even individual stages raced in England.
When Bradley Wiggins won the 2012 tour he became the first British rider in its 99-year history to do so. Fellow Brit Chris Froome's victory the following year and again in 2015 and 2016 means that France's biggest annual sporting event is now also one of the most eagerly anticipated by UK sports fans. This year Froome is hoping for a fourth win, although he has just lost the coveted Yellow Jersey to key rival Fabio Aru.
Newcomers to 'Le Tour' can find it all a bit bewildering, with various points classifications for sprinters, climbers, teams, young riders – and different coloured jerseys for each – and French terminology adding to the confusion. The main thing to know is that the winner is the rider who completes all 21 day-long stages of the tour with the lowest aggregate time.
Those 21 stages add up to around 2,200 miles of racing, including ascents of some of the toughest peaks in the Alps and Pyrenees. It is not for the faint hearted! Just short of 200 riders set out in 22 teams of nine riders each, but by no means all will finish the tour. Many are eliminated through injury, with crashes a fairly regular occurrence, while others find the relentless physical demands of the tour just too much.
While the modern Tour de France is a truly worldwide event, its beginnings were a lot more humble. The first Tour de France was held in 1903, devised as a way to boost circulation for a French daily sports newspaper, L'Auto. It was set up to rival the nation's biggest selling sports paper, Le Vélo, but initially struggled to make its mark.
At a crisis meeting in November 1902, its cycling journalist Géo Lefèvre suggested a six-day race of the type already popular on cycling tracks, but this one held all around France. The paper's editor, Henri Desgrange, was doubtful, but its finance director Victor Goddet was enthusiastic, handing Desgrange the keys to the company safe and saying: "Take whatever you need".
Ambitious early plans for the race brought just 15 entrants, but a revised format saw that number rise above 60. It was for a six-stage race held between July 1st and 19th, with several rest days between each stage. The stages were raced mainly at night to avoid closing the roads, and riders who averaged at least 20km per hour over all the stages were paid a small allowance, similar to what they could have earned working in a factory.
The first prize was 12,000 francs – six times what most workers earned in a year – with smaller 3,000 franc prizes for each stage winner. Among the competitors was 32-year-old Maurice Garin, from Lens, who would go on to win the first ever Tour de France. Around two-thirds of the riders dropped out and the last to finish was almost 65 hours behind the winner.
Crucially, the race had served its purpose, catching the attention of the cycling-mad French public and seeing sales of L'Auto more than double during the race. In fact, the passion for the race nearly ended it the following year, when several riders were beaten up by rival fans desperate for their man to prevail.
Cheating was also rife, with stories of riders taking trains, spreading tacks on the road to cause punctures for their rivals, and being pulled along by cars and motorcycles. One ingenious rider was found to be gripping a cork between his teeth, attached by a thin wire to a car further up the road!
Garin also won the second Tour in 1904 but, along with several other leading riders, was later disqualified for cheating and stripped of his title. It isn't clear how he had cheated. Despite these early setbacks, the Tour de France continued to grow and has been held every year except during the two World Wars.
Yet controversy has continued to dog the event, with use of performance enhancing drugs widespread in the 1980s and '90s, seriously damaging the event's reputation. One of its biggest heroes, American Lance Armstrong, was stripped of all seven of his Tour de France titles after the truth about his systematic drug use emerged.
Thankfully the Tour's reputation as one of the world's major sporting events has recovered as it continues to grip sports fans around the globe. This year's tour will finish in Paris on Sunday July 23rd, with daily TV coverage of the race on ITV4.
Pictured is Maurice Garin, standing with arms folded, winner of the first ever Tour de France in 1903.