Haas' Kevin Magnussen says a week of pre-season testing confirmed the driver's expectations that F1's new generation of cars are physically demanding.
The sport's new rules which have brought increased downforce and mechanical grip have clearly led to faster cars this season, and Magnussen clearly felt the strain after two days of solid running behind the wheel of Haas' VF-17.
"Yeah it's tough, especially I found under braking it's pretty hard on your neck," said the Dane who, like his colleagues, ramped up his physical preparation over the winter.
"But I got through it, and it's good to know where we need to work on."
Magnussen joined Haas following a year at Renault and had nothing but good words to say about the US outfit.
"It's a really well organised team. We have a good bunch of guys here, good engineers, designers, and Dallara is doing a good job.
"Really, really, really impressed with them. They stepped up their game.
"I wasn't here last year obviously so I can't tell really how they did then, but you know the job they've done this year with the quality of the car and the component and the chassis is very nice."
The former McLaren driver hopes to pick up next week where he left off when pre-season testing resumes in Barcelona on Tuesday, and continue the development of what he considers to be a very promising car.
"It feels very good. The work we've done so far has paid off, we've got a direction in which we need to work, and we're happy with the progress we've made so far.
"Of course we would've liked to have more laps yesterday but if you think about how small this team is, and the resources, it's not bad what we've done these two days."
