MOSCOW (AFP) - The secrets of Russian President Vladimir Putin's buff physique and youthful appearance are the result of herbal health remedies and swimming regularly to combat stress, his doctor revealed on Monday.

Mr Putin "doesn't look his age", the Kremlin's top doctor Sergei Mironov told Russian weekly Itogui, chiefly because the 60-year-old is "sceptical about medication".

Russia's strongman "prefers grandmother's remedies: tea with honey, the sauna or massage" to keep him looking young, complemented by regular swimming and taking care to get enough sleep, Dr Mironov said.

Although the president flew "more than the average pilot", he sleeps while onboard, Dr Mironov added.

Despite persistent rumours of ill-health and plastic surgery, Russia's strongman is well known for his photo-ready feats of athleticism, most recently landing a 21kg pike on a weekend fishing trip to Siberia.

"It's a habit in Russia to inflate stories about the health of our highest officials," the doctor said.

"I don't see a reason to keep this type of thing secret, though of course we bear in mind patient-doctor confidentiality." In late 2012, rumours swirled in the press about a back injury sustained during a paragliding stunt that forced Mr Putin to skip a meeting with EU leaders.

His spokesman Dmitri Peskov said that although the president did have an old sporting injury, it was not interfering with his ability to carry out his duties.

And in 2010, Mr Putin's appearance with a black eye poorly covered with makeup led to media speculation that he had undergone plastic surgery to lend himself a more youthful complexion.

A former KGB agent and black belt in judo, Mr Putin has also been pictured firing a crossbow at a whale in 2010 and commanding an inflatable raft amid high seas off the remote Kamchatka Peninsula in Russia's Far East.

In 2008 controversy erupted over Mr Putin's apparently heroic shooting of a tiger with a tranquiliser dart, just in time to save the assembled group from an attack by the beast.

Environmentalists later claimed the tiger was driven hundreds of kilometres to be used as part of a stage-managed stunt, the Guardian newspaper reported.

Media coverage of Mr Putin's leisure activities is carefully managed by the Kremlin to cultivate his image as a tough nature-loving action man, which his minders believe still appeals to many Russians.

Last month, Mr Putin dived in a small submersible to inspect a shipwreck at the bottom of the Baltic Sea.