Craig Williams was already on a weight loss program for the spring when he threw his hand up for the ride on Castelvecchio in the Cox Plate.
Castelvecchio is the only three-year-old in Saturday's $5 million weight-for-age feature and carries 49.5kg.
Williams says he feels great having already achieved the weight, the lightest he has ridden in two years.
Chasing a third Cox Plate victory after wins on Fields Of Omagh (2006) and Pinker Pinker (2011), Williams says he has been able to retain his strength.
“We've had plenty of time to work on doing it and we've done it right,” Williams said.
“We were already getting light and it worked out two weeks ago that we needed to get this light, so to have that management plan in place and being able to execute it, that's the good thing.”
“He is taking on these weight-for-age horses but he'll put himself in a great position from the draw (4),” Williams said.
“The first three-quarters of the race will all be about resting then we'll need a bit of luck.
“Hopefully we've got the horse to deliver.”
“He obviously follows the horse and really likes the horse, so we're very privileged to have him on,” Litt said.
“I think it's an honour to have him on and have a horse good enough for him to want to ride.
“That's very exciting for us.”