In Japan, which is hosting the Rugby World Cup this month, 150 clubs stage competitive matches for players above the age of 40 - and Tokyo's Fuwaku Rugby Club has three over-90s.
Of Japan's 120,000 rugby players, about 10,000 are over the age of 40.
Ryuichi Nagayama (below left), 86, says: "You tackle and battle each other but the gathering after the play is so enjoyable and fun.
"We talk about how each other plays and no-one gets angry about how we played. The atmosphere is great."
As a practising doctor, Mr Nagayama is very aware of the risks involved in playing a high-impact sport at his age.
The Fuwaku Rugby Club's website gives detailed advice on health precautions and includes links to a life-insurance company.
