In recent weeks, Putin has rarely left his official residence, sparking speculation that illness or injury had laid him low.
On Thursday, the respected newspaper Vedomosti cited unnamed Kremlin-connected sources saying Putin's September flight in a motorized hang-glider accompany migrating cranes had aggravated an old injury.
But his spokesman Dmitry Peskov told the state news agency RIA Novosti that Putin had an old injury, but it was not connected to the highly publicized flight.
Peskov was quoted as saying Putin was making only infrequent trips to the Kremlin because he didn't want his motorcade to disrupt Moscow's notoriously bad traffic.
The presidential motorcade forces the shutdown of large stretches of highway, an inconvenience that many irritated drivers mark by blaring their horns angrily as the president's car races past.
Putin has also put off several expected trips abroad, including to India, Turkey and Bulgaria. The Interfax news agency cited Peskov as saying there was no single reason behind those changes.
The hang-glider flight with the cranes, which took place in September just before an international summit in Vladivostok, was one of Putin's trademark adventurous media events. The 60-year-old Russian leader has assiduously cultivated an image of vigor and daring, including being shown swimming in a Siberian river and petting a tranquilized polar bear in the Arctic.
Putin also is a skier and a judo aficionado.
"Indeed he pulled a muscle. It happened before Vladivostok. He was suffering from some muscle pain then," Peskov said, according to Interfax.
"Actually, we have never tried to conceal it because any athlete has lots of injuries, which, however, do not mean any restrictions of his activities," Peskov said.
(Copyright 2012 by The Associated Press. All Rights Reserved.)