LONDON • There was a period during Mark Cavendish's difficult recovery from glandular fever when doctors restricted him to a maximum heart rate of 100 beats per minute, which, for a speed freak, was a form of torture.
He would go out training, this fearsome sprinter, and have to trundle along while middle-aged men in Lycra would surge past on their weekend rides.
"I was getting passed not even by amateurs in full kit but people with their helmets back to front," he said. There might even have been a few bikes with shopping baskets.
Given that his enforced go-slow was only a few months ago, it will be remarkable if Cavendish can put himself among the fastest men in the world at the Tour de France this month.
Only the Tour, with all its prestige, could have tempted Cavendish to the start line. The illness floored him, an elite sportsman needing to take a lie-down after walking up the stairs.
"I was absolutely on my hands and knees," he added. "It was horrible. Honestly, you feel like you are never going to be able to do anything.
My team manager... said at the time, 'You are going to be cooked next year'. But I went for it. It's just now I am paying the price.
MARK CAVENDISH, on being brought down to earth by the Epstein-Barr virus.
"That sounds exaggerated but when you are used to feeling tired from training and then you feel this bad and you haven't even done anything, as a professional athlete it's very hard to get your head around."
The debilitating effects of the Epstein-Barr virus were, he now realises, payback for a year when he tried to "aim for the stars - and I got pretty close to reaching them".
Last year, his workload and ambitions were vast as he chased the biggest prizes on road and track; a world champion in the velodrome in March, reverting to the road to win four Tour stages and wear the yellow jersey for the first time in July.
This was followed by a return to the track for his first Olympic medal in Rio with silver in the omnium, and then second place in the road race at the World Championships in Doha.
"My team manager, Rolf Aldag, even said at the time, 'You are going to be cooked next year'." Cavendish said. "But I went for it. It's just now I am paying the price."
The first signs of a depleted immune system showed themselves in Abu Dhabi in February.
At first, Cavendish thought that he had a bad cold. He won a stage but knew that he was not quite right. He was sleeping all the time.
On the bike, he was putting in the work but struggling to hold the wheel. He kept checking his equipment, wondering if there was something wrong. Then he started picking up injuries.
"It was my body telling me to stop," he said.
He raced on through Tirreno-Adriatico and Milan-San Remo in March but was due for a quarterly blood test with the UCI (International Cycling Union).
"That's when it came up that I was ill. It all made sense, feeling so bad, picking up an Achilles injury that I'd never had in my career," the 32-year-old Briton said.
But he got a lot worse before he got better. There were days when he was sleeping for 18 hours.
Worried that he was growing fat through inactivity, he even fled the family home and a stocked fridge in England and left for Italy so that he could better structure his diet.
Eventually, blood tests showed that he was ready to return, gently. It was doubtful that he would make the Tour but his team Dimension Data has invested a lot in him and not just in that salary of more than £2 million (S$3.6 million) a year, which runs into next year.
"The Tour is exposure for them and the Qhubeka charity," Cavendish added.
It may feel a very long road, and defeat will not come easy to a man who has won at least one stage in every Tour since 2008, and six in 2009.
"The hardest thing for me is sprinting and losing," he insisted.
"Not just because it's damaging to my morale, the team's morale, but it's actually good for the other sprinters' morale.
"The competitive fires are burning but I have to be realistic. It's like, you know, Ducatis are going to be faster than Hondas. I'm not firing like a Ducati right now."
But, he adds: "In sprinting, you can get lucky", which, in itself, makes him think it is worth a go.
THE TIMES, LONDON