NO sooner has Ishbel Holmes opened the front door than mayhem ensues. Out of the corner of my eye I see a flash of golden fur disappearing down the path. A few seconds later, a barefoot Holmes thunders past in pursuit, shouting: "Simba! Come back!"

It transpires that Holmes is dog-sitting and one of her charges has made a break for freedom. A search party is formed – me, Holmes, the photographer, some neighbours and a community group working on a gardening project – to comb the surrounding streets for an errant bull lurcher.

Finally, with the bold Simba lured back by the prospect of dog biscuits, we collapse in a sweaty heap in the living room. Curled up on the floor is Jack, a greyhound who Holmes is also looking after, and her own dog Maria, a whippet-cross she brought to Scotland from Brazil earlier this year.

It is perhaps fitting that interviewing Holmes should involve a canine-themed drama. The adventure cyclist is publishing a memoir, Me, My Bike and A Street Dog Called Lucy, which recounts her life-changing experiences as she pedalled across Turkey.

Part travelogue, part autobiography it charts her journey saving Lucy – and ultimately being saved herself – as Holmes sought to salve the battle scars from a fractured childhood and confront head-on the abandonment issues that have blighted much of her life.

It was four years ago this summer that Holmes, 37, from Stirling, set off to cycle the world. Her wanderlust was fuelled by more than derring-do. Holmes says she felt disillusioned and frustrated, her sense of self-worth eroded by years of neglect and abuse.

"I never spoke about my past because I was so ashamed of who I was and all the things that had happened," she says. "I thought it was all because of me and what a bad person I was."

Scots-Iranian by birth – she changed her surname from Taromsari last year – Holmes was five when her parents split. Her father left and moved to England. Holmes was visiting him when an acquaintance of her father sexually assaulted her.

"He asked me to sit on his knee," she writes. "When I did, his hand travelled up the inside of my leg. That was the moment when I knew, really knew deep down, that I was a bad and awful girl. And I began hating myself. Just like that."

It is a memory that Holmes had suppressed for many years – and only surfaced as she cycled through Turkey. She credits that to finding a kindred spirit in Lucy, a three-pawed street dog that began following her on a coastal road along the Sea of Marmara.

Holmes saw herself mirrored in Lucy: a fellow soul who had been broken and rejected by others. Having initially tried to cycle away as fast as possible ("I kept repeating the mantra: 'I'm cycling the world and stray dogs are not my problem,'" she says) it became clear the dog wasn't giving up.

She has no idea why Lucy chose her. "I didn't clap her or feed her," recalls Holmes. "I didn't even notice her at first. In bike racing, it's called the 'blind spot' – where you tuck in behind your competitor and stay out of sight, conserving energy – and that's where she was, just padding along."

It became her single-minded mission to get Lucy safely to an animal sanctuary some 340 miles (550km) away. She fashioned a dog carrier from a wooden crate fastened to the front of her bike and off they set.

Lucy towered above the handlebars, attracting laughter and curious stares. Yet, undaunted the pair cycled through an unforgiving landscape where they were chased by packs of wild dogs and Holmes frequently had to fend off unwanted interest from leering men who would shout: "Sex!".

Along the way Holmes's voice grew from a whimper, hamstrung by fear and doubt, to a mighty roar. At the same time, she was slowly beginning to piece together the sequence of events that had led to her throwing a leg over the saddle to traverse the globe.

"I never had flashbacks before," says Holmes. "I was the queen of blocking things out. Then, when I met this street dog, there was so many parallels between her and me."

Cycling across Turkey opened a floodgate of memories, but it was only while writing her memoir that Holmes was able to process the tsunami of emotions it had unleashed.

Her story makes for tough reading. By the time Holmes was nine, she was punishing herself by not eating. At 13, consumed by self-hatred, she would think of ways to kill herself. Holmes kept this building inner turmoil hidden from everyone, not least friends and family.

During her teens, Holmes's relationship with her mother began to deteriorate, marred by heated arguments.

When Holmes was 15, her mother called social services and asked them to remove her daughter from the family home. She was placed in foster care. It only compounded all the negative things Holmes already believed about herself.

At 16, she was walking back to her foster placement from a Saturday job stacking shelves when two men stopped their car and asked for directions to a nearby loch.

Insisting they were lost, the men suggested Holmes get in and show them the way, promising they would bring her straight back. They drove her to a remote spot where she was raped.

"It was like a self-destruct button had been pressed," she says. "This is the sad thing about it all. It's not about me being in foster care at 16 – it is the fact I was happy that bad things were happening to me because that was my punishment for being such a bad girl that my own family didn't want me.

"I used to look around me at school and see what the other kids were getting up to – and they were doing some naughty stuff and being caught – but they all had families and I didn't so that meant I must have been worse than everyone else."

After running away from foster care and leaving school, Holmes worked in a biscuit factory to pay for B&B accommodation. "The only other option was to go into a homeless unit for 16 to 18-year-olds and I was too petrified to do that," she recounts.

Holmes paints a picture of a young woman adrift in the years that followed, too numb and damaged to form any real or lasting bonds. Cycling would become her saviour and the creation of her World Bike Girl blog saw the first seeds of a new identity began to take root.

In 2009, Holmes cycled the length of Pyrenees from the Mediterranean to Atlantic and toured France, Spain, Andorra and Portugal. She took up bike racing and when the Sir Chris Hoy Velodrome opened in Glasgow in 2012, Holmes was talent-spotted for having a flair for track sprinting.

Her goal was to gain the qualification time to compete for Team Scotland at the 2014 Commonwealth Games in Glasgow, but that plan was derailed when Holmes was knocked off her bike after a collision with a car while on a training ride.

Afterwards Holmes suffered anxiety when cycling on the road. She was referred to a therapist trained in cognitive behavioural therapy (CBT), paid for by an insurance policy. Within weeks, says Holmes, the therapist began trying to instigate an inappropriate relationship with her.

"He thought he had fallen in love with me," she writes. Emotionally and psychologically ill-equipped to deal with the situation, Holmes says it left her feeling "utterly destroyed". She lodged an official complaint and following a hearing, the therapist was struck off.

The official report, she says, stated that his behaviour suggested a pattern of grooming, but according to Holmes the biggest shock was reading that her personal history had made her vulnerable to predatory behaviour.

It was only then the penny dropped. "That was the point I knew I had issues from the past," she says. "I didn't assert myself. If someone wanted to harm me or do bad things, I would have allowed it."

Holmes had a sudden sensation of the rug being pulled from beneath her. "I was really angry about it," she says. "I felt like that bad experience took away any opportunity I had to deal with what had happened in my past. I went through a full mental breakdown.

"I had worked so hard to get to where I was in life. I started out with nothing. I didn't have food, a bed or one single human being. I had to work so much harder than a lot of other people. Then I went into therapy and had a really bad experience. I felt like I was back where I started."

She had broken off her round-the-world cycle to return to the UK for the hearing. Holmes flew back to Turkey in mid-December 2014, a time when the Syrian refugee camps along the country's southern border were becoming perilously full.

In the months that followed, countless refugees approached Holmes asking her to record their stories. "I kept saying: 'I have a cycling blog. I'm not a journalist.' But they didn't care. They just wanted their stories recorded somewhere in case they died.

"At that time, when I arrived on the Turkish-Syrian border, it was before the mass movement into Europe began. The refugee camps were over capacity. There was no room left."

Most she met faced an unenviable decision about the future. "They'd had to flee Syria because they were going to die or be tortured," says Holmes. "In Turkey, they didn't have anything, but they were safe.

"Their choice was to stay there and suffer as their money ran out, leave by boat and risk drowning or go by land and potentially be shot.

"I had dinner with one Syrian family and later got a message from the father to say they were about to board a boat and if anything happened to them would I please publish their story, so that people knew they existed.

"The mother was pregnant, and they had two small children. They were getting on that boat and knew they might die. In Turkey, they hadn't been in danger, but they were stuck in limbo. That is the decision they faced."

Holmes later heard that attempt had failed and the family subsequently travelled overland as part of the mass migration of refugees across Europe to Germany.

During her time in Turkey, she and Lucy became famous. Word spread through social media, TV and newspaper reports about the Scottish girl who had rescued a street dog.

"When you are cycling the world, you are around strangers every day," she says. "Then suddenly it hit the news and everywhere I went people seemed to recognise me – often in the most random places. I went to watch a big pro-cycling road race and I got invited into the VIP area.

"Everywhere I went people knew who I was, and they knew Lucy too which was amazing. She got so much love. It was magnified because everyone had seen us on the news and wanted to meet Lucy. They were so happy and loved her. She gained so much from that."

Holmes made a promise to Lucy that she would help other street animals around the world and has since gone on to cycle across Chile, Argentina, Bolivia and Brazil.

Last year she returned to Brazil, rescuing former stray Maria and another dog Murphy. Both animals were close to death due to advanced tick disease but are now healthy and living in Scotland (Maria with Holmes and Murphy with a family in Aberdeen).

Their story will form part of a future book, along with Holmes's other experiences which included being robbed only hours after arriving in Anchieta in south-east Brazil. Holmes was unhurt, but her camera equipment was stolen.

"Afterwards I cycled back to the last place I felt safe," she says. "That was a campsite in Marataizes where I had first met Maria. I has been talking to some locals and misunderstood the Portuguese because I thought they were saying she was already owned.

"That is common in Brazil where dogs on streets have owners who feed them. I was so disappointed and cycled away. I got 40km [25 miles] and that's when I lost all my camera equipment. When I went back to the campsite, I learned Maria was a street dog and adopted her.

"I had no intention of adopting a dog, but I fell in love with her," says Holmes. "Maria gave me ringworm the first day that I met her. I had ringworm up my arm."

When Holmes began writing her memoir, something jarred. She realised the words being poured onto the pages were those of a mixed-up 16-year-old girl rather than a confident 37-year-old woman and made the decision to return to therapy.

"I'm a million times healthier now," attests Holmes. "It is like I have gone back to the undamaged Ishbel which is amazing because now I can enjoy life."

Despite short-lived glimmers of hope for a reconciliation with her parents – Holmes reached out to both her mother and father last year – she has since made the painful decision to cut ties for good.

"I had just started writing the book and realised there was a chance I could self-sabotage but thought: 'No, I'm not doing this any more. I need to be free to live my life.' The door is closed. It is finished. That door will never be opened."

There's no bitterness as she says it. Rather, Holmes has adopted the sanguine view that the term "family" doesn't need to apply only to those with whom you share biological ties (she speaks fondly of 75-year-old Jack, a kind man who used to help fix her bikes, with whom she spent last Christmas).

Holmes is pedalling into the future and not looking back. "I feel lucky and blessed because I know there are so many adults out there that haven't had the positive experiences I've had in recent years," she says. "My past isn't dictating things or pulling the strings in my life any more."

That doesn't mean the process of telling her story has been easy. "Once I submitted the book to the publishers I panicked and thought: 'What the hell am I doing? I need to get that book back, there's no way I can share what I have,'" says Holmes.

"I was in a panic thinking that I had made a huge mistake. Then the #MeToo campaign kicked off and I knew 100 per cent it was OK to share my story. I'll always be so thankful to #MeToo."

It is apt that she chose Holmes for her new surname because finding a permanent home between her travels is very much on her mind.

"I'm thinking, 'what if?' because I have no idea will happen next," she says. "Do you know what the 'what if' is? It's what if I could get Maria and me a home. If that happened it would be my ultimate dream."

Me, My Bike and A Street Dog Called Lucy by Ishbel Holmes is published by Bradt Travel Guides, priced £9.99. The author will be cycling on a UK book tour from August 15. Visit worldbikegirl.com and ishbelholmes.com