The Briton told Reuters at the Hungarian Grand Prix that he first met the Serbian in Monaco some years ago and admired his professionalism and dedication to human performance.
"I bumped into him at the gym and we walked home together," explained Russell.
"We’ve shared ideas together and he’s been really open with me with things he’s trying and what’s working for him," added the two times race winner.
"We’re just talking, many different ideas. Physical and mental.
"I don’t want to share too much because they are private conversations but I just really like how he’s constantly wanting to learn more and that inspires me to learn more about myself, what works for me, what works for them and pushing the boundaries."
Russell, whose seven times world champion team mate Lewis Hamilton is 39 and moving to Ferrari next season, said Djokovic wanted to learn more about motor racing and planned to attend a grand prix.
"There’s a lot that he knows that I won’t and vice versa and you’ve got to take all these ideas from the best in each profession and see what you can take for yourself," he said.
"I feel fit, healthy and in a great place right now at the age of 26 but I need to make sure that I’m fit, healthy and as motivated in 10 years’ time, 15 years’ time, who knows 20 years’ time.
"I’m trying to put in work now."
Russell attended Wimbledon with his Spanish girlfriend this month, with Djokovic losing in the final to Spaniard Carlos Alcaraz.
"I love the tennis. It’s probably my favourite sport to watch. I don’t play tennis but (I have a) huge amount of respect for the players," said the driver.
"For these tennis players, their body is like how the car is for us.
"We’ve got man and machine, for them they are out there by themselves so the physio, the training, the cooling, the hydration, the nutrition - all of that is the fuel that we put in our car, the aerodynamics."
