It is the reason why, 52 years after taking his first session, the septuagenarian can still be found at Meadowbank Stadium six days a week, gently cajoling elite performers, kids and those with a disability alike to shave one more second or inch from their previous bests in pursuit of their own personal glory.
It is also the reason why he will spend tomorrow afternoon at the Kelvin Hall in Glasgow, awkwardly stepping into the spotlight at the Aviva International Match to be presented with Winning Scotland Foundation's annual Winning Difference Award 'in recognition of his exemplary achievements and significant and lasting contribution to Scottish sport'. Walker scoffs at the suggestion he might mark the occasion, insisting that it is more cause for concern than celebration.
"I'm worried that by getting this they maybe think I'm about to die or something, that's the danger at my age," he says, judiciously ignoring congratulations.
Instead, he insists, his reward comes from the success of those in his command. And how rich that reward has been. Some of Scotland's finest have come under his tutelage over the years, most notably Alan Wells, who worked on his starts with Walker in the months leading up to his 100m gold in the Moscow Olympics.
"A coach is only good if they've got a good athlete and Alan was never satisfied and always looking for improvement," recalls Walker, clearly more at ease when not talking about himself. "He always felt he couldn't be perfect so he was self-motivated, which served him well when he went out and beat every American afterwards after people tried to talk down his achievement."
The increasing paucity of world-class Scottish competitors in the intervening years means winning a track-and-field gold in London later this year is unimaginable. As much as it pains Walker to acknowledge as much, the fact is that athletics struggles to attract the most gifted youngsters in the face of more financially appealing disciplines, such as football, tennis and golf, amid an ever expanding sporting spectrum.
Consequently, the standard has dropped – "at one time I had two part-time 800m runners doing 1.45/46mins who would be superstars now" – despite the prevalence of sponsorship deals and development of more appealing facilities affording young Scots a better chance than ever to reach the top in their chosen event.
"It's still feasible if they are prepared to work but I think it's a different animal now," Walker says. "Kids don't have the mobility and range of movement they once had because they are always sitting down playing on computers rather than being outside. Sure, we are working on identifying those weaknesses and working on them but without those basic motor skills we are starting from a lower level and their technical capabilities are limited because of that."
With that in mind, Edinburgh Athletic Club take kids in at the age of nine but cap their membership to ensure the coach to athlete ratio remains 1:12 and release those who fail to show sufficient talent so others on the waiting list can be afforded the opportunity.
One thing they must do, though, is demonstrate an appetite for work. Having completed his national service with the RAF first in Bath, then Leuchars, Walker values discipline highly, even if his ability to run the 440 yards in 49.1secs on grass ensured his time in the forces was far from taxing. "There weren't enough jobs for everybody so I was pushed into sport to get rid of me," he explains. "I ended up running with them and basically getting a big skive because I was practically a full-time athlete. In fact, it was so good that I signed on for an extra two years."
When he did finally leave the RAF, Walker worked at electrical engineering firm Ferranti and it was there that he began coaching, setting up sessions for colleagues who had spotted him training alone. That continued when he moved to Heriot-Watt as a physics lecturer – guiding, among others, Herald Sport's athletics correspondent and erstwhile steeplechase hopeful Doug Gillon – and has not abated.
"It keeps me young and, as long as the athletes are giving me everything, I'm happy," explains Walker, whose science background led him to dabble in photo finish and electric timing technology years before it became popular. "If they are committing themselves, they deserve the same commitment back but I won't tolerate skiving. If they are wasting my time I will tell them, no matter what level they are at. With that attitude, I think they'll have to carry me off the track in a coffin in the end but that would maybe be quite a nice way to go."