Jolyon Palmer is warning that any driver lacking an optimal level of fitness at the start of the season will be 'found out' by the big physical demands of F1's 2017 cars.
The regulation changes ushered in this season will thoroughly put the emphasis on downforce and increased cornering speeds, and they will take their toll on anyone who starts the year unprepared, says the Renault driver.
"I can see it making a difference," Palmer said.
"We don't really know exactly the performance: we know the numbers, but we don't know what the tyres are going to do.
"If it is what we think, then I think it will show early on who has been in the gym over the winter and who hasn't. If drivers aren't in the gym this winter they will be found out.
"It is clearly much quicker than we are racing now, it will be a challenge to drive, physical as well. I think it will be really exciting."
The jury is still out as to whether the huge changes will have any impact on overtaking and the quality of racing in general. According to Palmer, we won't find out the exact outcome until the lights turn green in Melbourne at the end of March.
"We won't know until we hit the track," he said.
"You can look back and see when cars had a lot of aero it was quite difficult to follow, thinking 2007/2008, they didn't have DRS and they were still overtaking.
"Some of the slipstreams were massive and at the moment we are not getting much, so there will be a double effect. We will only properly know in Melbourne I think.
"I think the cars going quicker will generally be a bigger challenge, but there will be some corners that will be less of a challenge because they will be flat."