When a blood test in April confirmed that the unaccounted-for fatigue haunting Mark Cavendish was due to an Epstein-Barr viral infection, Team Dimension Data had a problem.
The Tour de France was just three months away and their world-class sprinter was now in the grip of an unpredictable viral infection that could jeopardise his entire season.
It's difficult to over-state the value of Cavendish to Team Dimension Data - indeed, to any team he might ride for. Consider the Manxman's record: An Olympic medallist and world champion on the track, a world champion on the road, and the most successful sprinter in Tour de France history.
In fact, his 30 Tour de France stage wins are second only to Eddy Merckx's all-time record of 34. And Cavendish is still only 32.
After the Epstein-Barr virus (EBV) diagnosis, Cavendish followed medical advice and rested. When he got the green light to resume light training, he had good days and bad days. He was often forced back into periods of total rest. It was six weeks before Cavendish could think about training normally again, and by then there were only six weeks left before the Tour.
He ultimately made it to the start line of the Tour de France, but his fitness was still a work in progress. He placed an impressive fourth in the Stage 2 sprint, but two days later was caught up in a race-ending crash with Peter Sagan in the final 100m of Stage 4. Whether the Cav Comeback could have ended in a dream Tour de France stage win was instantly relegated to the realm of speculation.
But Team Dimension Data, accurately self-styled as 'Africa's team', are hardly built around just one man. Their stated aim, regularly articulated by team owner Doug Ryder, is to put an African rider on the podium of the Tour de France or to produce an African world champion on the road.
Thirteen of Team DiData's current riders are African (seven South Africans, four Eritreans, an Algerian and a Rwandan), while the remaining 15 athletes hail from three other continents: Europe, North America, and Australia.
And if DiData have only two Africans at the 2017 Tour de France (current and former South African champions Reinhardt Janse van Rensburg and Jaco Venter), the three other Africans in the Tour peloton this year - Louis Meintjes, Daryl Impey and Tsgabu Grmay - have all previously passed through the team.
No team has done more to put African cycling on the map. From trailblazers like Adrien Niyonshuti (Rwanda) and Daniel Teklehaimanot (Eritrea), to future stars such as Nic Dlamini (South Africa) and Merhawi Kudus (Eritrea), Team DiData have written the book on how to tap into the vast potential of African cycling.
Combine that developmental know-how with the experience of working with a world-beater like Cavendish and the result is a fascinating blend of coaching insights.
KweséESPN sat down with Dr Carol Austin, Team Dimension Data's head of performance support, and with team coach Dr Jon Baker, who works closely with Cavendish, to hear some exclusive insider tips.
1.How tough are pro cyclists?
"Every single rider in the Tour de France is a world-class physical talent," says Dr Austin. "I don't believe there is any other sport that requires such a high level of physical conditioning and such extreme mental toughness.
"All these guys are prepared to push themselves to a different level of pain. Race routes are highly demanding in terms of distance, duration, ascent and danger, as well as extreme environmental conditions.
"This is not a job; it's a calling. These riders love what they do; they wouldn't be able to do it otherwise. It's just too hard.
"Pro cyclists also have to be risk-takers. If you're too scared, you're unlikely to be successful. The risk-taking is calculated, based on each rider's skills and experience. Mark Cavendish choosing to take that gap on Stage 4 was an example.
"Bunch sprints require a particular combination of physical talent, tactical smarts and fearlessness. The risk of crashing is high and when you crash in a bunch at 60km/h, there is a real chance of serious injury.
"When Cav crashed on Stage 4, I was relieved that his injuries were limited to a fractured scapula, lacerated finger and abrasions. Crashing into the barriers at 60km/h and then being ridden over by another cyclist going at 60km/h could have resulted in far worse injuries. That's the reality."
2.What makes Mark Cavendish so special?
All Tour de France sprinters are primarily endurance athletes. They have to be, because before unleashing that fast finish at approximately 90 percent of peak power output, they first have to make it through five or six hours of racing. Unsurprisingly, Cavendish is a very powerful, explosive rider.
"But he is also exceptional in terms of in terms of his aerodynamics in the final sprint," says Austin. "He is a small guy but through all his track work and his years of experience, he's learned to reduce his drag by sprinting with his head down and shoulders lowered."
A 2013 study by Italian sports scientist Paolo Menaspa showed that if a cyclist can reduce his aerodynamic drag (chiefly by reducing the frontal area that generates air resistance) by as little as 10 percent, he can expect an increase in speed that will equate to a 3m advantage in a 14-second sprint.
With sprints regularly being won or lost by a matter of centimetres, Cavendish's aerodynamic sprinting style is clearly a huge asset.
In his analysis of what it takes to win a sprint during a grand tour, Menaspa also highlighted the importance of team tactics, specifically the positioning of the sprinter and his teammates in the final kilometres.
Ideally, a sprinter would like to have two teammates leading him out in the final minute or kilometre of the race, with one teammate still at his disposal in the final 30 seconds. Similarly, the sprinter's own position is crucial.
Having analysed 31 sprint stages during the 2008-2011 grand tours, Menaspa concluded: "Not a single victory was obtained when the sprinter was further back than ninth position with one minute to go. Similarly, no sprints were won if the sprinter wasn't in the top six at 30 seconds to go."
This is what Austin means when she talks about Cavendish's split-second decision-making: "Cav is exceptional in how he works with the team. He has a long-standing partnership with his lead-out guys, particularly Mark Renshaw, and when things don't go perfectly, he's able to wing it by himself. It's all about being in the right place at the right time, and going exactly where you need to go."
Dr Jon Baker identifies one final component to Cavendish's skill-set: "Absolutely, he needs to be very good at sprinting, but the rest of the time he's just surfing wheels and following his teammates.
"I don't want to say it's easy, but his power output during a stage is always one of the lowest. Mark is very efficient in the peloton. He's very good at conserving energy and he has very good teammates who shelter him from the wind. He floats around and then wins races. It's incredible."
3. For a young rider, what is required to make it as a pro?
"If you haven't made it in European racing by the time you're 22," cautions Austin, "the likelihood of finding your way into a pro career becomes slim. 'Making it' means performing in European UCI-sanctioned races.
"In 2016, the Dimension Data Continental team was set up to support this development pathway. Our Conti team consists of ten African riders, who are predominantly U23. We develop these riders over a two- to four-year period using a science-based, progressive approach, as well as by racing in Europe.
"When we identify African talent for our Continental team, we look at a rider's physiological profile and his UCI race history. European races are much longer and harder than even high-profile local events, so we're looking for riders who can take on this level of challenge and competition.
"If you do make it onto our Continental team, you then have to take things very seriously from that point onwards in order to get an opportunity with a Pro-Continental or World Tour team by the end of your U23 career.
"Being a pro requires high levels of discipline and commitment at an age when most youngsters are still exploring, experiencing and experimenting. There's really not much window for partying during the year - maybe two or three weeks at the end of the season."
4. Behind the scenes, what do cycling fans seldom see?
"Very few people understand how demanding the travel is," says Austin. "The travel is pretty unglamorous. Sleeping, packing up, moving on - sometimes during the Tour, the riders have no idea where they are in France. It's a blur; they're living in the moment.
"Sometimes the hotels are good, sometimes they're awful. For a third of the year you're living out of a suitcase. From the outside, the Tour de France looks absolutely glamorous. On the inside, it's actually more like glamping (glamorous camping)."
5. What kind of training does the Tour de France demand?
Put simply, in order to race 3500km, a cyclist first needs to be able to train that distance. Says Austin: "From the age of 18, we're moving most of our Under-23 riders from training about 1 800km per month towards 2 500km per month. At World Tour level, the standard expectation is an average of 2 500km per month."
What does that equate to in hours? "As 18-year-olds, we're moving them from training maybe 60 hours per month to consistently doing between 80 and 100 hours per month on our World Tour team. Which means, on average, about 1 000 hours or between 28 0000 and 32 000km per year."
6. Is it only about the miles?
"There's the physical adaptation, and then there's learning about efficiency and tactics," explains Austin. ""Efficiency means doing as little as possible to get from the start of the race to the finish, while still delivering on your individual race role.
"Mark Cavendish is a master of this. During a race, Cav does as little as possible until it really counts. Steve Cummings is another example. He races really smart; when his day comes, he gives everything and has a high rate of success.
"Efficiency is something that develops over time. A lot of skills need to be acquired along the way. More experienced riders use the slipstream of the peloton and coast or soft-pedal for 15 - 25 percent of a race. They anticipate and respond to the challenges and opportunities that play out in a race and are generally more relaxed.
"In contrast, young riders tend to do more work. As a result of poor positioning, they may only coast or soft-pedal for 6 - 15 percent of a race. They may be less skilled in descending, which results in more time and energy spent chasing back. They might fear losing the peloton if they go back to the team car to collect bottles and food.
"As a result, they can end up under-nourished or under-hydrated which limits their in-race performance and post-race recovery. To be able to ride through the cars or to pick up a musette, to defend efficiently or to descend efficiently - it takes time and European racing to learn these skills.
"Louis Meintjes was the fastest-developing rider we've ever seen on our team. When we took him to his first Tour de France, he was 23 years old. But he had been building towards that for three years and had UCI results going back to 2009, when he was 17. Louis is a very calculated rider. He knows his limits and respects them. He's smart, and he's still far from his career peak."
7. How did Cavendish pull off his epic comeback from EBV?
Team Dimension Data's doctors couldn't predict the course of the EBV infection, or Cavendish's recovery timeline. But they knew that only rest and supportive treatment (painkillers, anti-inflammatories, adequate hydration) would get Cavendish to the point of being asymptomatic enough to start training again.
"The recovery programme was very focused on Mark's perceptions of how he was feeling," explains Baker. "He would get up some mornings and say, 'I feel shattered today. I can't do this'. So then it was a day or two off. Or, if he went out riding and actually felt okay, he'd do a bit more.
"Normally, we work more scientifically: you know how much load a rider can take and you can push that limit just enough, every day or week or month. But with EBV you don't really know where that limit is. It's a perception, and it doesn't show up so well in the power data.
"Although Mark is an incredible sprinter, cycling is an endurance sport. If he can't ride 200km, he's not going to be there at the end to contest the sprint. Good aerobic endurance is critical so it was very much about volume training rather than intensity.
"Mark would do zero hours per week, then 10 hours per week for a week or two, then 15 hours for a week or two, then 20 hours for a week or two. But it wasn't a clear-cut, linear build-up. It was more about mini-blocks and phases to get back to two hours a day, then two and a half hours a day, then three hours a day.
"About midway through, Mark started doing two sessions a day: an hour and a half in the morning, then another hour or so in the evening. So he would still get a three- to four-hour ride in during that day, even though he couldn't manage it all at once. The process was all Mark-led."
8. What can amateur riders learn from 'the Cav cure'?
"First, understand where you're starting from," says Baker. "Assess your level of fitness on Day 1, and then look at the training that is appropriate for that.
"With Mark, at the start we maybe assumed he was fitter than he was, given the effects of EBV. Maybe we did too much too soon. Knowing where you are when you start is really important.
"Then, look at where your goal is and, working backwards, figure out what is key for that event. The Tour de France was Mark's goal, so having the endurance to get to the finish was most important. Ensuring Mark's body weight was matched to his power to get over the hills was also important - and the same goes for most amateurs.
"There really wasn't an awful lot of sprint training because that type of thing improves really quickly with most riders. You can make relatively bigger gains in peak power in a couple of weeks, whereas it takes months to get endurance and climbing strength.
"To lose weight, maybe you train a little bit more every week to burn calories, or eat less junk food. Set periodic goals and every couple of weeks check how you're progressing and adjust if necessary.
"You also need to be able to deal with hiccups. Maybe you miss a week of training because of work - that happens. Mark missed a couple of weeks through the illness. So we said, 'Okay, this has happened, let's re-adjust and be flexible'. Don't be rigid. Being able to go with what life throws at you is important."
9. Where to now for Cavendish?
After doing all the work to defy Epstein-Barr virus, to get to the Tour de France and then be increasingly competitive in the sprints, it must have been a bitterly disappointing experience to crash out. How to re-group?
"Mentally, I'm sure he's disappointed," says Baker. "It's a setback, but he's been through these things and I'm sure he'll go through it again, unfortunately. This is a hard sport.
"Physically, with these upper body injuries, although you've got a broken bone, you can still ride on the indoor trainer. I'd expect Mark to back to his pre-crash form in a week or so.
"He'll be disappointed but he'll be looking for new goals. Mark is very goal-orientated. He'll be looking at the calendar and saying, 'Okay, maybe I can win something here, or here.' I think he'll be positive and looking forwards. He'll be looking to make the biggest comeback he can."