Part of that post read: "for the track team…Success is not final. Failure is not final. It’s the courage to keep on that matters..…for 2021".

Cowan, born in Hackney, north London, was an international high hurdler who went on to coach a generation of grateful British athletes including world and Olympic 400 metres champion Christine Ohuruogu and Commonwealth Games and European 110m hurdles champion Andy Turner.

And his life bore out the message he posted about having the courage to keep on.

Having taken over the career of Ohuruogu in 2005, he guided her to the Commonwealth 400m title in Melbourne in 2006 - but shortly afterwards her expected challenge for the European title in Gothenburg was traumatically ended as she was banned for a year after becoming one of the first and highest-profile athletes to transgress rules on her whereabouts, failing to be contactable for a random test on three occasions within an 18-month period.

The independent disciplinary committee that imposed the ban was unanimous, but added the comment that she had been guilty of a minor infraction due to "forgetfulness". The crucial third failure had occurred when Ohuruogu had arrived at her normal training venue in Mile End and found it was full of schoolchildren, so then drove over to the Crystal Palace arena without changing her notification of whereabouts.

In the aftermath Ohuruogu, a linguistics graduate from University College, London, was shocked and considering retirement because of the automatic Olympic ban that went with such doping cases according to a British Olympic Association statute.

History records that she won an appeal against that ruling "due to significant mitigating circumstances" and she went on to win the Olympic title in Beijing, having become world champion in Osaka just a few days after her ban had elapsed.

Four years later, in a stadium less than a mile from where she had been brought up, Ohuruogu added an Olympic silver at the London 2012 Games from lane eight, before winning a second world title in Moscow the following year.

Ohuruogu, who retired in 2018, told The Times last year: "The new breed of coaches are more like scientists but he [Cowan] was one of those who saw sport as an art.

"Lloyd never went to the Olympic Games or the World Championships but he had this way of being that meant he was the only person I would listen to.

"Nobody could get in my head like he could."

In October 2007 she recalled how Cowan had given her the impetus to carry on with her career while she was, effectively, in the wilderness. "There were some times when my coach, Lloyd Cowan, really had to give me a kick to keep me going. But I’m glad I didn’t give up during my low points."

When Ohuruogu's Olympic ban was overturned a month later it emerged that Cowan’s quick-thinking and action had prevented her inadvertently missing another test while suspended when she was training at Pickett’s Lock in north London, which would have meant returning to competition with one strike already against her.

"The testers were sitting up in the bleachers while Christine was training, watching all the athletes getting on with things, but they didn’t make themselves known," Cowan recalled. "When we found out who they were Christine had gone.

"They thought she was coming back, but I told them she had gone home. I didn’t even wait to ring her - I drove the guys straight to her house."

Cowan was someone who would always give you a straight answer when you spoke to him. He was also a gent. In the dizzying wake of Ohuruogu’s Olympic victory in Beijing, when the world wanted to speak to her, he noticed a female radio reporter in some distress after being apparently sidelined by the media organisation, and deliberately took time out to answer her questions. Classy.

The outpouring of emotion from athletes he had coached, or even tangentially helped, has been extraordinary.

Ian Hodge, the hugely knowledgeable athletics statistician, posted: "As a hurdler he was successful internationally, as a coach he reached the absolute peak, as a Man he had unmatched influence on those he met in the sport."

Britain’s former European 200m champion and world 4x100m gold medallist Adam Gemili posted: "The athletics community has lost a real one. Lloyd Cowan wasn’t just a great coach but also just a great human. It didn’t matter if you were Olympic Champ or just starting out, he was always willing to help athletes any way he could. You will be missed dearly."

Turner, pictured with Cowan above, commented: "Heartbroken, absolutely heartbroken to hear that my coach Lloyd Cowan had passed away. 12 good years with this man. I owe him everything. Gutted."

Later he added: "There will never be another @cowanlloyd, truly one of a kind. Lloyd knew me better than anyone, we had some amazing times and even better stories along the way. He made such an huge impact on my life, what a sad, sad day."

The other post on Cowan’s Facebook was this: "Know the true value of time; snatch, seize and enjoy every moment of it. No idleness, no delay, no procrastination; never put off till tomorrow what you can do today."