1. Empty tanks
This morning's 20th and penultimate stage of the Tour was doubtless among the most beautiful for spectators, but possibly the most hellish for the competitors.
Tired riders cleared the saddle in Annecy, home to one of Europe's purest lakes, overlooked by a 12th century chateau and nicknamed the Venice of the Alps.
After three weeks of intense heat and gruelling riding, the 170 riders remaining from the original 198 had to resist the temptation to ditch their bikes and jump into the cooling waters of Lac d'Annecy. Instead, they had to chug up another two massive climbs on a 125km trek that included two fierce ascents up Mont Revard, a Category 1-level climb, and then an HC up to the finish in Annecy-Semnoz. They are called HC, which stands for Hors Categorie, because they are considered so tough they are beyond classification.
Chris Froome entered this morning's stage with a whopping lead. His closest rival, Alberto Contador, is 5 minutes, 11 seconds back. Realistically, it would take a serious mishap for Froome on Stage 20 for anyone else to carry the day in Paris tomorrow morning.
The race's final stage is flat, meaning Froome's Sky team will be watching closely for any attempted breakaways.
But more than that, tradition and fatigue hold that the ride on to the Champs-Elysees is largely ceremonial, at least until the expected final sprint.
2. Contador pushes on
Contador, now 30, is simply not the dominant force he once was at the Tour. The two-time Tour champion, back this year following a ban over a positive doping test, says he's matured and learned how it's important to be calm in high-stress situations.
On the roads, though, he hasn't let up and has injected panache into the race, trying nearly everything to cut the lead of Froome, with only mixed results.
In one flat stage, he caught Froome and his Team Sky off-step and erased more than a minute of his deficit. Then, he pedaled all-out in the final time trial, finishing second and losing by just nine seconds to Froome.
Sensing that Froome can't be beaten in the mountains, Contador has attempted attacks on treacherous downhills or in valley flats - places where it's hard to make up time.
At times, that all-or-nothing approach has led him to burn out too early, as in Thursday's ascent to the finish at the famed Alpe d'Huez in Stage 18.
Unlike other rivals who just want to get a podium spot, Contador says he won't settle for second-best: "For me, finishing second or 10th is the same thing."
3. Food glorious food
On big days of racing like Friday's, when riders cover more than 65km of climbs and can munch through 7000 calories, they need to eat the right amount of food and take it in regularly. The calibrations are rider-specific.
Omega Pharma QuickStep doctor Helge Riepenhof says it's more about carbohydrate intake than calorie intake.
Many riders chow down on pasta, porridge, some fibre and muesli at breakfast, but they also need to take a break before the stage then eat again as the stage starts.
"On a hard day like [yesterday], they know there's no chance to survive unless they eat what we give them."
Too much food can lead to an upset stomach; too little can deplete blood sugar levels, and riders run out of gas.
Sky sporting director Nicolas Portal said Froome gobbled down a bowl of rice at the finish in L'Alpe d'Huez on Thursday, after running short of sugar on the climb. At his warm-up on Friday morning, Froome said he had porridge and an omelette.
Teams load their cars with energy bars and gels. And after weeks of fine-tuned feeding, riders often get fed up - literally.
"The last thing you want to do is wake up and stuff your face with food. But it's just putting fuel in the tank: a lot of pasta, porridge, cereal, bread, omelette," Orica GreenEdge veteran Stuart O'Grady said.
Garmin Sharp rider David Millar said he eats "just gels" nowadays. "Literally, food's just horrible to me now ... I don't want to talk about it."
4. Adieu, tour engineer
The man behind the crafting of the Tour route and keeping its often-unwieldy caravan in line is calling it a day.
After 36 years, including three years as a rider himself, Jean-Francois Pescheux is bidding adieu.
Since the mid-1990s, he's had a job of connecting the dots between the French towns that pay to host a Tour stage start or finish, and ensuring that everything runs smoothly once the race begins every year, including by using his baritone barking into the race's CB radio to keep vehicles from disrupting the riders' advance.
The centennial edition, he said, isn't necessarily his masterwork: Tour organisers "offer up a menu and it's the riders who manage it".
At times when he believes he's laid out a great mountain route that's likely to provide superb race drama, the racers don't necessarily comply.
Over the years, Pescheux has seen the race evolve from a somewhat parochial European affair into a global sports phenomenon, and insists it must maintain its character despite growing popularity.
Pescheux says he'll keep his eye on his successor, to ensure it remains true to its roots.
"A cycling race is about a start line and finish line. The rest is decoration ... if the decoration doesn't remain just that, then one day the Tour will be in danger."