Twitter has broken down social barriers, put boys in touch with girls and allowed fans to rejoice in the inane mutterings of their idols. Yesterday it brought perhaps the greatest cyclist together with a town that, to put it kindly, is a bit of a stranger to extreme physical activity.

Lance Armstrong, the seven times Tour de France winner, alerted his fans on Monday evening that he was in Scotland and would be cycling through the streets of Glasgow the next morning. On his Twitter site he posted: “Hey Glasgow, Scotland!! I’m coming your way tomorrow. Who wants to go for a bike ride??”

A later posting said: “Hey Glasgow — ride’s at 12 noon. Location tbc. Stay tuned! Still dialing it in. And yes, I have my rain coat!”

Yesterday morning the cyclist, who was in Glasgow to see a U2 concert, posted that he would be starting outside the Ashtree House Hotel in Paisley, home to Scotland’s most deprived estate and where health professionals have long anguished about diets, lifestyles and mortality rates. When asked whether he knew much about cycling in Paisley, Armstrong admitted with a smile: “I know nothing about it.”

Yesterday he did his best to improve the nation’s health. Hundreds came on to the streets on a variety of bikes while scores more lined the town’s high street to cheer the impromptu ride. He said he and his team had decided two nights previously to attend the U2 gig at Hampden Park. “I said, ‘Hey, let’s have a bike ride’. It’s a chance to meet lots of people,” he explained.

Those who turned up to meet a man who is a hero to many after his battle with cancer and his determination to raise awareness about the disease, admitted that the event felt surreal. Alexander Sneddon, 41, of Rutherglen, Glasgow, said: “It started off a little bit vague on Twitter. I wasn’t sure what to make of it. It just seems so incredible to be here. To be so close to the great man is unbelievable, he’s such a hero.”

Julie Watson, a nurse, aged 44, from Fife who has been cycling for ten years, agreed that the event was “a bit out of this world”.

“It’s quite dream-like,” she said. “It’s a chance in a lifetime to ride with my hero. He’s an inspiration that I’ve followed for years.” Also joining Armstrong was former world champion Graeme Obree. “It’s fantastic — I know my friends will be jealous,” said the Scot, who broke the one-hour distance record in 1993 and 1994. “He does have such a draw.”

The appreciation appeared to be mutual as Armstrong later described Obree — on Twitter, naturally — as a “legend”.

“Thanks to everyone who turned up to ride in Paisley! I figured we’d have a nice ride for a dozen or so. But 100s came. Haha! Awesome!”

“And hopw [sic] great was it that the Flying Scotsman Graeme Obree came out?? Legend.”

Armstrong said he had had no route planned when he arrived at the hotel at about noon. He took the majority of the 150 or so riders, who had the appearance of serious cyclists kitted out in expensive helmets and clothing, on a two-hour journey around the town. Most of those with bikes appeared to have come from other parts of Scotland while those on foot were local. Police closed the High Street while the cyclists got under way.

It also seemed that Paisley was a hit with Armstrong. Before heading to the concert, he tweeted: “Just up from a quick snooze. U2 tonight at Hampden Park. Could be a late night. Still buzzing from the ride 2day. Loved it.”

He is due to compete in the Tour of Ireland, which starts on Friday.