AGED 24, Alastair Humphreys left his home in Airton to cycle round the world in August 2011.

He was waved off by his dad, David, who mused how far he would get.

In fact, his journey along the length of the Earth’s three great landmasses (Africa, the Americas, Eurasia) took more than four years to complete.

He rode from England to South Africa, crossed the Atlantic by yacht and then cycled from Patagonia to Alaska. Crossing the Pacific by freighter, Alastair completed his expedition by cycling back to England from eastern Siberia.

Adventurer Benedict Allen called the ride “an epic adventure” and Sir Ranulph Fiennes described it as "an old-fashioned expedition: long, lonely, low-budget and spontaneous. It was a life on the road rather than a whirlwind break from home.”

There were blood, sweat and tears along the way, but Alastair returned home triumphant after cycling an amazing 45,000 miles around the world.

Familiar surroundings, home cooking and Christmas and birthdays with friends had all been put on the back burner while he completed his ambition to cycle across five continents and 50 countries.

Alastair completed the challenge mostly alone - and for his favourite charity Hope and Homes for Children.

His achievement, which began as a dream back at university in 1998, was totally his own doing. He even financed the adventure after failing to get any financial sponsorship.

He saved £7,000 from his university loans which he estimated would last him four years if he was frugal. It did.

He also managed to earn a bit extra by teaching occasional classes in various countries en route. Some children lapped up his adventure while others looked at him as if he was an alien, or just plain mad.

He said his journey had made him more optimistic and positive about people.

"Many of the countries I went through were poor, but people were extremely generous offering accommodation and food. To them I was a curiosity.

To be honest, most people thought I was totally mad. Being fair haired and white, I looked totally different. Most of the time people just stared," he said.

His memories included seeing East African Masai warriors wearing customary red cloaks and Manchester United shirts, eating fried worms, scorpions and sheep's head and talking his way out of trouble with the Japanese police for riding his bike naked!

Alastair purposely slowed down on his last leg through Europe so he could enjoy it. "I could easily have sped up knowing I was almost home," he said.

Ironically, he had escaped injury until just miles from home when he fell off his bike at a roundabout in Keighley!

After four years, Alastair rode into Airton to a welcome by friends and neighbours who have been following his journey on his website and in the media. But he remained totally unaffected by the enormity of his achievement which saw him go through three Rockhopper mountain bikes.

"I'm very glad to be back, knowing that I achieved what I set out to do, but because I have been travelling so slowly it has been part of my life and part of living for the past four years. I haven't yet had time to look back and think about what I have done," he said.

Mum Jenny told the Herald she hadn't realised just how relieved she was that he was back safely until he rode into Portsmouth.

"I purposely had tried not to worry up until then, even though I can worry for England, but it hit me when he got back, " she exclaimed.

Dad David also sent a silent prayer up each day that he stayed safe, but was not unduly worried about his son.

"He's a grown man and I knew he would be able to look after himself. People in this world are basically good. I knew he would never be refused help if he needed it, " he said.

Ten years ago, Alastair was considering what he was going to do for a living. He was qualified to teach biology at high school level, but was hoping to earn money by giving talks, after-dinner speeches and slide shows.

Today he describes himself as adventurer, author and motivational speaker - and he still a wanderlust.

He describes himself as adventurer, author and motivational speaker and over the past decade, has taken on the icefields of Greenland, crossed Iceland on foot, canoed 500-miles down the Yukon, trekked 1,000 miles into the Empty Quarter desert, walked 600 miles across India, taken part in the Marathon des Sables - described as the toughest race on earth - and rowed 3,000 miles across the Atlantic.