Cycling: From poor amateur to the world title, Mark Cavendish reveals his hardest journey

With three days left to go as reigning world champion, British cycling star Mark Cavendish yesterday gave the world's top junior riders a compelling masterclass in what they face if they continue in the sport – and warned them that, at higher levels, the challenges did nothing but increase.

The star speaker alongside the Dutch Olympic gold medallist Marianne Vos at a conference organised as part of the week-long World Championships in Maastricht, Cavendish pointed out that, compared with junior racing up to 18, amateur racing – the next category – "was almost a different sport" in which you "could not take anything for granted.

"Suddenly you're racing against amateurs who could be in their thirties and could have been racing at that level for years. You have to keep training and training and there's a big difference in a physical sense," Cavendish explained.

"At junior level the maximum permitted for a one day race was 130km [81 miles], and you could get by if you were a bit fat and trained for three or four hours.

"Suddenly you have to teach your body to resist a pounding that can last for days. It's no longer a hobby. The hardest thing I had to learn as an amateur was maintaining that kind of physical consistency."

Cavendish also revealed he had been "nothing special on the world level" as a junior but had still had an inner conviction from a young age in his talent as a cyclist – and had channelled a large part of his energy towards improving it.

"When you're 14 you know when you're good enough for something. I did everything I could towards that. I learnt German and French at O level and, because GB wasn't that big in cycling at the time and I had to go to mainland Europe, I had to leave school at 16 and go and work in a bank for two years to get some money."

Asked to advise the juniors in their upcoming World Championships races – today is the women's while the men's take place on Sunday –Cavendish said: "Don't change anything you normally do, treat it like a bike race even if there's a medal and a [world champion's jersey] at the end of it.

"But putting on that GB jersey and doing your country proud is something that's really important, too, he stressed."

Other areas covered by the UCI's two-hour conference ranged from the role of supervising races to the media and equipment. The euphemistic term "prevention" was used to introduce the fight against banned drugs.

However, the whisper that went up among the public as Cavendish stepped into the auditorium midway through the congress indicated that the world champion was one of the biggest draws for the juniors present.

The GB junior coach, Matt Winston, said: "Moving into the amateur level is a massive step and, although you can prepare the riders for when they enter the U-23 [amateur] category, it's a huge thing to hear it from someone as well respected as Mark.

"Things like him working in a bank or something to do with education rather than being a full-time rider at that age – which is not something we would want for a junior – are important for them to pick up," Winston emphasised.

Looking at today's race, where GB junior Lucy Garner will be defending her world champion jersey, he said: "The course is very different, so it doesn't necessarily play to our strengths, but... we will be going out there to try and get a result.

"We have got riders to cover the breaks," he added. "And if it is still a bunch of riders together at the top of the [final climb of the] Cauberg, then we will be in with a good chance, too.