If the modern Tour de France is considered one of the toughest sporting events in the world, then spare a thought for the cyclists that attempted the challenge back in 1928.
Their steel bikes had no gears, marginal brakes and weighed twice as much as the modern equivalents.
Many of the roads were unpaved and of the more than 160 men who started the journey, only 41 finished — the highest attrition rate of any Tour de France.
Fast forward to present day and two mates have attempted to cycle that same route — on the same metal bikes — to honour a unique Australian-New Zealand foursome that made history in the race 89 years ago.
"I've always had a fascination with stories about underdogs," said one of the cyclists, Phil Keoghan, who is perhaps best known as the host of The Amazing Race.
"I found this great book about the history of cycling in New Zealand and they wrote about a guy called Harry Watson who was from my hometown of Christchurch.
"I started reading and realised he was the first New Zealander to ride in the Tour de France and a member of the first English-speaking team to ride in the Tour."
Watson was joined by three Australians — Sir Hubert Opperman, Ernie Bainbridge and Percy Osborne — who together made the six-week trip by sea to Europe for their historic ride.
They were a group of four pitted in time trial stages against teams of 10 in the 5,632-kilometre race.
They were considered crazy by many of the European locals, with one French journalist writing at the time that their attempt was "nothing short of murder".
Yet they persevered, and three of the team were among those that completed the ride.
To celebrate their success and ensure the story would live on, Mr Keoghan and friend Ben Cornell spent five years preparing to recreate the ride, and a documentary on their effort, Le Ride, has just premiered in Australia.
"Here's the thing — I wish I could sit down and talk to Sir Hubert Opperman and talk to Harry Watson and talk to these guys about what it was like," said Mr Keoghan, who directed the documentary.
"Because I can't talk to them and I want to really give the audience a sense of how difficult it was, I thought if I put myself in the story, maybe the audience would see me suffering and understand just how hard it was for them.
"I guess I like the abuse."
It took Mr Keoghan three years to track down an original 1928 bike that he could use on the ride. After that he and Mr Cornell set about tracing the original route by car to see if it was actually possible to follow it.
For the most part they were successful, but some previously small roads had since become unrideable highways and other roads were closed off. Still, they found a way through.
They averaged 240 kilometres a day for 26 days, cycling the circuit around the edges of France and across both the Pyrenees and Alps mountain ranges.
They confronted their own challenges — not least the "death stage" that took them 23.5 hours to complete.
"The feeling of satisfaction now, with all the reflection, is not just going over those legendary climbs in the middle of the night, but knowing that these humble men who lived in a time where you didn't skite, you didn't show off about your achievements, that their achievements will not be forgotten now," Mr Keoghan said.
"They should be celebrated."