I'm not sure how Renault does their fitness and mental training, but there has been stories about McLaren's work in the last months since they work with a Finnish fitness centre and have a Finn for a team doctor. According to Kovalainen, McLarens approach physical and mental training is more professional than what they had at Renault.
In that sense Dennis's comments, which BTW are similar to what he has said before the first race, wouldn't be far off the truth.