Dhaka, March 21 -- Cristiano Ronaldo was 40 last month and is top scorer in Saudi soccer's top flight. Lewis Hamilton hit the same age in January after an eighth Formula One title. LeBron James, also recently 40, is the first NBA player to score 50,000 combined points.

They are big name examples of the growing multitude of modern sportspeople performing at remarkable levels at an age when in yesteryear they would probably be long retired. Experts attribute the growing longevity in elite sport to a host of steadily-evolving conditions: from improved diet and mental wellbeing to better recovery and training facilities.

"A whole constellation of factors . it's like pouring gasoline," Canadian performance nutritionist Dr Marc Bubbs, author ...