The Spain international revealed new boss Antonio Conte has put extra effort into building up the players’ fitness.
And Pedro believes their superior conditioning has helped them storm to the top of the Premier League table.
“I have worked with many managers, but this is the one who has made us train the hardest, definitely,” he told the Telegraph.
“We’re all very fit, unlike last year when we weren’t that fit”
Chelsea forward Pedro
“But it’s very good because you can see the results of it.
“It’s not just me, everyone in the team is very physically fit right now.
“We’re all very fit, unlike last year when we weren’t that fit and we were not really at the top.
“This year, Diego and everyone, we are all very fit and we are all working really hard.”
Conte has attracted plenty of attention for his passionate displays on the touchline.
He angered Jose Mourinho for whipping up the Stamford Bridge faithful during the thrashing of Manchester United.
But Pedro has defended his manager’s displays.
“The manager is a strong character and a passionate guy, and he’s very emotional,” he said.
“He’s always on the lookout.
“He’s screaming and shouting at everybody and making everybody go a little bit more and I think that helps us.
“I do hear it in games, you can’t not hear it!”