The Leicester City legend, 38, has five goals in 15 Serie A games so far this season.
After their 2-2 draw with Cagliari, Vardy was asked about his secret behind his fitness: "I think it's a matter of experience and knowing how to manage my body.
"I know exactly what it takes to be ready for the game, and I take care of rest even when I'm at home; I think that's the main thing. These are all aspects to take into account."
Asked if he is enjoying himself, Vardy also said: "If I didn't enjoy it, I wouldn't play anymore. It's my passion, and that's why I'm still on the pitch today. We'll keep working, analyze what went wrong, and try to figure out how to improve for the next match."
On his first-half of the season, Vardy added: "On a personal level, playing always helps, I feel good: I hope to continue like this for the rest of the season.
"The standings are positive, but we can't afford any lapses in concentration. We had a good first half of the season and we need to keep pushing. Fingers crossed and hope to get enough points to play in Serie A next year too."