By Toby Davis

LONDON (Reuters) - At 50 years old, Spanish table tennis player He Zhiwen has a simple mantra for staying at the top of a sport reliant on reflexes, speed and agility.

"I take care of myself, I eat Chinese food and I get good rest," the world number 41 said after bowing out of the Olympics in the third round on Monday.

"I lack the speed, but I am really good at serving and the tactical side of things."

The Chinese-born He took up the sport in 1971, 17 years before current world number one and Olympic favorite Zhang Jike was born, and competed in Athens and Beijing.

Playing with a particularly awkward-looking pen-hold grip, he nips around the table with cat-like reflexes that belie his age.

His London Olympic campaign ended in disappointment when he was beaten 4-2 by the higher-ranked Adrian Crisan from Romania.

"I am probably not going to be at the Rio Olympics," He said as he emerged from his duel dripping with sweat. "I am 50, but we'll see." (Editing by Sonya Hepinstall)