Wood leaned out over the break and showed up to the annual pre-season media day looking significantly fitter.
The move has been welcomed by Walkinshaw Andretti United.
On the eve of the Sydney 500, his team boss Bruce Stewart lauded the 21-year-old for dedicating himself to cutting back.
“It’s fair to say the team is super excited. The drivers are well prepared. I don’t know if you’ve seen, but Ryan Wood looks like his younger brother right now,” said the WAU CEO.
“That’s been an amazing thing for the team because to see a super talented young driver like that go away and then come back so well prepared — everyone is a foot taller and it’s a credit to Ryan and it’s great for the team.”
Stewart said there was no directive from the team to lose weight, but noted Murphy had been in Wood’s ear.
Murphy has acted as a mentor to Wood and worked hands-on with him at the Taupō Supercars round during his rookie season.
“I’ve got to be quite frank, it’s been off his own bat,” said Stewart.
“Ryan has a mentor in New Zealand, a really strong-willed character called Greg Murphy.
“The guy, we’ll call him Murph, doesn’t take fools easily so he was quite direct in his feedback.
“It’s great for Woody to have someone like Murph there because they are so strong together.
“And I’ve got to give a shoutout to Greg and all of his family who have supported back in New Zealand because he came back from New Zealand and we were like ‘Wow!’
“It’s so good, it’s such a huge culture jab in the arm, it’s great.”
Wood was a standout in Race 1 of the season, finishing 11th after a spirited battle with Triple Eight’s Will Brown.
“Qualifying was really good today, it was nice to be in the top 10. Disappointed I didn’t quite piece it together in part two but we have another shot tomorrow,” said Wood on Friday.
“I had some pretty fun battles out there with Will, the Mobil 1 Truck Assist Racing No. 2 didn’t quite have the race pace towards the end of each stint so it was hard to fight at the end there.
“We go again tomorrow, we have a bit of work to do overnight, we know we have the pace to be starting further up the field tomorrow, just got to piece it all together, looking forward to it.”
