The Tour de France is often held up as one the greatest examples of sporting endurance on the planet.
To win it takes nerve, guts and no short amount of skill. The 104th edition of the famous event will provide another demonstration of that fact when it begins in Dusseldorf on Saturday.
A field of 198 riders will take to the roads of Germany, Belgium, Luxembourg and of course France to compete across a distance of 3,540 kilometres, spread over 21 stages.
Only a select few will be vying for the coveted maillot jaune and fewer still are considered genuine contenders.
Here we take a look at those best placed earn the honour of riding down the Champs-Elysees bedecked in glorious yellow.
Best finish: Winner (2013, 2015, 2016)
Not since Miguel Indurain has a man won three Tours in a row, but that is the achievement that Chris Froome stands on the brink of.
The Briton - who famously ran up the last stretch of Mont Ventoux on the way to prevailing in the 2016 Tour - would in fact become only the fifth rider to win the race on four or more occasions, having also taken the honour in 2013.
It would solidify a reputation that already places Froome among the all-time greats, especially as he has conceded this course does not play to his strengths.
Team: BMC Racing
Best finish: Fifth (2016)
Richie Porte is a man in form. This year he has claimed two overall race wins and four stage triumphs, as well as second spot at the Criterium du Dauphine, making him a serious threat in the general classification.
A former team-mate of GC rival Froome, Porte's 2016 Tour was hampered early on as he suffered a puncture on stage two, leaving him playing catch-up.
He fared well over the remainder of the race to underline his threat, but needs a little more luck on his side this time around.
Best finish: Second (2013, 2015)
Mr Consistency, Nairo Quintana has taken a spot on the podium in all three of Tours in which he has competed.
With Vuelta a Espana and Giro d'Italia honours already to his name, Quintana is aiming to become the seventh rider to win all three Grand Tours, but Movistar have another GC contender in the shape of Alejandro Valverde.
He finished second at this year's Giro, citing illness as a factor for his apparent fatigue in some of the mountain stages. A fully-fit Quintana is a frightening prospect.
Best finish: Winner (2007, 2009)
As one of the riders to have won all of the Grand Tours, there can be no doubting Alberto Contador has the experience and the talent to take out a third Tour de France.
He is in his debut season with Trek-Segafredo and has the backing of a strong team, but he failed to complete last year's Tour as a fever forced him to quit on stage nine.
This year he finished second at the Paris-Nice, but only managed to place 11th at this month's Dauphine.
Team: AG2R La Mondiale
Best finish: Second (2016)
Home hope Romain Bardet carries the burden of expectation on his shoulders, with no Frenchman having won the Tour since Bernard Hinault's fifth success 32 years ago.
Known for his attacking instincts, Bardet has shown steady improvement at this race and demonstrated his class with a solo triumph on Mont Blanc last year.
In moments such as that he has looked every inch a Tour de France champion and, as the youngest of the main contenders, he is well set to one day achieve that goal.
KOM THRONE HOPEFULS
One area where there is a strong chance of home glory is in the King of the Mountains category, where Thibaut Pinot and Pierre Rolland are among the leading contenders.
But they will have to dethrone reigning champion Rafal Majka, while all the leading GC hopefuls are also in with an outside chance.
It is a rare feat for a rider to take overall success and prevail in the mountains, but Froome achieved it in 2015.
The French must pine for a return to the days of Richard Virenque, who was the KOM ruler seven times from 1994 to 2004 amid a spell of Gallic dominance that also saw Christophe Rinero and Laurent Jalabert join the party.
SPRINT DEMONS IN CONTENTION
Perhaps the safest bet in the Tour is Peter Sagan taking the honours in the points classification.
You have to go back to 2011 for the last time the Slovakian failed to finish top of the pile - but then he did not make his debut in the race until the following year.
The charismatic 27-year-old is odds-on to defend his title, amid competition from the likes of Marcel Kittel, Arnaud Demare and Andre Greipel.
Mark Cavendish- who has won 30 Tour stages - was the man who took the crown prior to Sagan's ascendance, but the Briton may struggle to find his best form after a recent bout of glandular fever.