Thirty years ago, in the searing heat and smothering humidity of Tokyo, Liz McColgan laid waste to her rivals and became 10,000m world champion.

McColgan junior has faced an array of challenges throughout her career, from serious injury to loss of funding, a change in events and what her mother and coach describes as “health issues”.

Yet, aged 30, she has roared into form as the Games loom, shattering Paula Radcliffe’s 5,000m British record – a benchmark that had stood for 17 years.

“It was like a coming of age, all that hard work and all the disappointments,” says Liz McColgan, a former Commonwealth champion and Olympic silver medallist.

“She is world class. She has just shown people how good she is. I have believed all along, but others haven’t.”

Having competing at London 2012 – her first Olympics – as a steeplechaser, McColgan switched to focus on the 10,000m and 5,000m.

But in the lead-up to Rio 2016, she spent 18 months sidelined by an ankle injury and a host of related issues, then had her funding cut by British Athletics.

“There has always been some form of negativity about her running and I think Eilish doubted herself a lot of the time – ‘I am just not good enough’,” says her mother.

“She has really not had a lot of support from the governing body. She was told if she wanted to be on funding, she had to drop me as her coach. She has had lots of issues with low iron, problems with heart palpitations and she has always had problems with her periods.

“I think a lot of people would have given up but, Eilish being Eilish, she has just battled against it. It shows that through determination, you can still achieve great things.”

‘It’s a partnership, a discussion’

The dynamic between mother and daughter, coach and athlete, has evolved over the years.

Eilish was a nine-month-old infant when Liz stormed to gold in Tokyo and grew up watching her mum compete. Now the roles are reversed and Liz feels a deep swell of maternal pride when she sees what her offspring has accomplished.

“When your daughter does something pretty amazing, as a mother it just overrides everything,” she says. “As a coach, to have an athlete that has achieved that standard, is really good on my part.

“Eilish is 30 now, so it is not like I’m telling her, ‘this is what you’re doing’; it’s a partnership and it’s a discussion. We are just in a really interesting time now where she is on the top of her game. The next couple of years are going to be really exciting for both of us.”

Tokyo will present new and exhilarating challenges. McColgan’s mother believes a gold medal is just beyond her, given the strength of the field, but is confident she can earn a podium finish.

However, she will not be able to travel to Japan to be there trackside.

“It would have been really special to go. I did a lot of my best running in Japan; I set the world record for the half marathon there, I won the Tokyo marathon, I won my world championship there,” the 57-year-old says.

“You have got to look at it holistically and say in the big scheme of things, me not being able to go is just a very small bit, I am just surprised and happy that the athletes are allowed to perform at the Olympics.

“So I will watch it on the TV and get as nervous as everybody else and wish I was there.”

‘I just want to do my family proud’

For Eilish, honouring her mother’s legacy gives her “a real drive”.

“Every time I get close to my mum’s PBs or better them, I just know that she’s exceptionally proud to be part of that,” she told BBC Scotland.

“It’s her training that has allowed it. There’s definitely a family, emotional element every time I compete now because I just want to do my family proud and do the name proud.

“Having someone who’s been there and done it and have that person be your mum, is just another motivational factor.”

The younger McColgan is fully aware of the challenge she faces in Tokyo.

“There’s probably about six women, three of which are from Ethiopia, that could probably break the world record tomorrow or the next day,” she explained.

“So the depth in those events is absolutely crazy and it could be that I go there, I run a huge personal best, a national record, the fastest time in GB history, but finish eighth or tenth. Equally, a PB could get me in the top four or top five and I’d be over the moon.

“I’m not putting any medal expectations on myself. Certainly in the 10,000m I’d love to break my mum’s national record, which is 30.57. That’s something that I’ve felt all of this year that my mind was set on.”