Dmitry Medvedev told Finnish media that Putin does a lot of sports to stay in shape.
Asked whether Putin had any serious injuries, Medvedev said that he had "nothing serious," adding that "each of us has some small things we have to address."
Putin has canceled several foreign trips in the last few weeks and spent most days at his suburban residence, visiting the Kremlin only rarely. One newspaper report claimed that he had injured his back in a widely publicized flight with Siberian cranes in a motorized hang-glider in September.
His spokesman denied the claim and said that Putin pulled a muscle during judo training.
Medvedev's comments were released by his office on Wednesday.