My son’s not just a champion swimmer – he made me change my life

Bert said his son had set world records and won gold on a bigger stage – but that the victory in Glasgow was “as emotional as the first one”.

He added: “I realise that my little kid – who is now a pensioner! – was unbelievable in what he achieved.”

In a wide-ranging interview with BBC Scotland, 69-year-old Bert said his life had been “revolutionised” by his son.

He recalled how Chad had prompted him to quit smoking at age 12 – he asked his father to give up the habit instead of buying him a Christmas present.

Bert hasn’t had a single cigarette since that day.

Bert – who weighed 140kg (22 stone) at the time – also stopped drinking every day and lost 41kg (6.45 stone).

“He made me change my life,” said Bert.

“I would probably be dead now if I had continued the way I was. That’s a good lesson for other parents.”