It's Tuesday afternoon but the usual rush of endorphins generated by his morning training session is absent, the low water levels of the Clyde making it too dangerous to row. Consequently, he is grouchy and lethargic, but it would take a brave man to venture that taking a day off is perhaps not the worst thing at his age.
Day celebrated his 80th birthday in January, yet four times a week – summer or winter – he can be found at Clydesdale Amateur Rowing Club's Glasgow Green boathouse preparing for a 60-minute stint with the three other pensionable members of his crew. He might have six or seven years on Owen McGhee and Duncan Paterson, and more than a decade on Mike Colgan, but the oldest member of the quartet bristles at any suggestion that his colleagues might be carrying him.
"Not at all," he chastises. "I go to the local gym myself on a Wednesday morning and do weights and all sorts, but the boys tell me to give it a rest because they can't do it. Furthermore, I keep on getting in bother because I'm rowing too hard – it's a bit of a sore point."
Slowing down, however, is something Day refuses to contemplate. As long as he continues to enjoy the sport he first experienced 66 years ago, and he has people willing to row with him, he will keep going. What would he do with himself instead?
The Glaswegian readily concedes that the prospect of what might become of him should he stop scares him, a concern perhaps fuelled by experience. Nine years have passed since the death of his long-term partner Ian Stanners, a man he taught to row and with whom he competed with great distinction on the veterans circuit for almost 15 years, winning the World Masters Regatta eight times.
"One Sunday morning, we had a tremendous session then, on the Monday, he phoned to say he wasn't feeling too well," Day recalls. "He thought he had rheumatism or some such so we decided not to bother weight training that week but I never saw him again. Less than a fortnight later he was dead."
At that time, Day was a member of the Clyde Rowing Club but was invited for a row by various other organisations along the river "just to help me out". Few of those clubs, though, would have failed to recognise the alluring prospect of enticing a world champion to join them. Clydesdale were ultimately successful in doing so, and matched the Bishopbriggs native with their own veteran crew in an association which has since yielded a series of Scottish Championship successes.
That should come as no surprise given Day's past. As well as his World Masters domination, he also rowed for Scotland in the 1958 Empire Games in Wales, finishing third some 14 years after taking up the sport. "I was playing rugby at Allan Glen's School and I broke my nose when a scrum collapsed," he explains. "A pal of mine found out what had happened and suggested I try something different and took me on a tram down to Glasgow Green, where I started rowing. I was tickled pink by it but I wasn't allowed to go out in a boat myself until I learned to swim -"
By the time he began his national service in 1953, that slight problem had been overcome and, two years later, he survived a rigorous selection process to be included in the 12-strong RAF rowing squad that travelled around Europe for regattas.
"I don't know how I managed to get away with it; for six months I was out of uniform and into a boat," Day says, chuckling. "My most memorable race was in Hamburg; the RAF had destroyed the city just a few years earlier but they seemed to have forgotten that when they welcomed us."
Another occasion, on which a friendly conversation with a Russian rival in Amsterdam was disturbed by the furious intervention of a diminutive female KGB agent, is among his most cherished recollections from a career during which he served as vice-president of the Scottish Rowing Association, welcomed The Queen and Duke of Edinburgh for the 1986 Commonwealth Games and served on the selectors panel for the Olympic Games in 1980 and 1984.
Unsurprisingly, then, he has no ambitions left to fulfil but insists that should not be perceived as any indication of an impending retirement. "I think they're going to have to carry me out of the Clyde," he says. "I've mentioned to my wife Eileen about stopping once or twice and she's said 'no, no, carry on because it keeps you healthy' and she's quite right, of course. I enjoy it and that's the key; that and keeping up with the boys. Or maybe getting ahead of them -"
Contextual targeting label: