Rosberg believes that a driver reaches his peak during their early 30s - but that experience counts for a lot in contrast to raw speed.
"The best age for racing drivers is 30, 31, 32 - and that's because your ability as you're getting older slightly decreases, but experience counts for so much in this sport," Rosberg said.
"So experience will outdo the small decrease in your natural ability as a human as you get a bit older."
Hamilton, who will turn 35 next January insists that he doesn't care what Rosberg has to stay, as everyone has their own opinion.
"I've never seen the blog," Hamilton said. I don't know who follows it, but it has no bearing on anything that I do. I don't care, everyone has their own opinion.
"Whether he's right or wrong, I don't really care. All you have to do is look at my tally of results over the years and they kind of speak for themselves.
"So naturally there will be people that have not had the success that I've had, and might want to talk it down, but that's okay. I'm 34 years old, but I feel like I'm driving better than ever. Hopefully today you can see that I've not lost any speed.
"Qualifying is not always going to go great, you just have to move on. Races are not always going to go great, the last one [Germany] sucked.
"But you know what, you move straight on, let it go. There's nothing you can do about the past, all you can do is try to shape the future.
"Honestly, I couldn't be more proud. Ultimately you want to be proud of yourself, and I feel really proud of myself today, how I drove, because that's how I always want to drive, and then how we delivered as a team."
Bahrain International Circuit - Winter testing