COLIN Hill is 74; his grandson Shane 'Shano' Dwyer is 17 and every week they send each other head over heels as they practise Aikido, the Japanese "art of peace."
Colin said he was attracted to Aikido as part of keeping active rather than for its self-defence benefits.
"I'm a pretty quiet sort," Colin said.
"A friend was doing it and I just wanted to get into something."
"It's mainly if people attack you, you know how to defend yourself."
He has been doing Aikido for 19 years and was a 2nd Dan before he changed styles.
He joined sensei Kevin Andrews' Woolgoolga class just over a year ago and said because of the different style involved, he was back to being a beginner at Aikido.
His grandson joined him six months ago and Colin said Shano was enjoying it so much he would like to work out every night
Colin has macular degeneration and no longer drives.
Instead he walks and rides his bicycle.
He said in addition to these forms of activity, Aikido's stretching, rolling and harmonious movements helped him with his asthma and emphysema as well as some back problems.
"It helps me a lot with my breathing," Colin said.
"I used to swim every day, but it was getting so I couldn't regulate my breathing when I was swimming."
Colin said even if his chest felt tight at the beginning of an Aikido session, he could feel his breathing improving as he began rolling and flipping and it had solved his back problem.
It has even helped him cope with accidents.
When a car clipped his bicycle from behind when he was cycling, a bystander, who happened to be his son in law, said he saw Colin instinctively drop into a roll which cushioned his fall.
Colin, a retired technician, said some other martial arts styles were 'a young man's game' but Aikido allowed men and women of all ages to participate.
"You don't need strength" Colin said.
"I weigh 70kg and I'm only five feet five tall.
"You use the other person's strength and movement."
"If I can do it, anyone can."
Colin's sensei, Kevin Andrews, who has been practising this original Aikido style from Tokyo for 38 years and teaching it for 30, said while it was based on ancient and lethal Japanese flighting arts, today it was used purely for protection.
That said, anyone who attacks an Aikido exponent is likely to find themselves surprised and if they persist, probably floored.
Kevin said he had needed to use his defensive arts only three times and the third time only counted as half because his attacker was so drunk.
He said Aikido exponents, like some musical instruments, improve with age.
During a trip to Japan in 1991 for a major Aikido gathering, Kevin discovered it was the elderly masters who had truly mastered the art.
"The old guys were the ones that you wanted to train with," he said.
"They were absolutely lethal.
"These were 80-year-olds - the oldest was 92 and he wasted me for an entire afternoon."