Cole admitted last week he missed his clashes with the former Manchester United star.
Ronaldo told Sport-Express: "Ashley Cole. He's a very tough, tenacious football player. And others don't miss an opportunity.
"In England players are constantly tackling. Everyone tries to kick you. But if you're in good physical shape and quick enough, then you can dodge it.
"There are more injuries, blows, tackles and players are more physical. In general, it's much more of a battle (in England). Referees don't protect players as much and aren't always whistling for fouls.
"All the same, I still like the English league. That and the Spanish league are the best two national championships in the world."