(Photo: San Diego Zoo/Ken Bohn)Xiao Liwu is a Giant Panda at San Diego Zoo.

A panda cub is getting buff, according to his vets at San Diego Zoo. Panda cub Xiao Liwu has been slimming down and gaining more muscle on his legs, vets announced after his 6 month check up this week.

The 6-month-old cub reportedly now weighs 19.4 pounds (8.8 KGs) and measures 24.6 inches long (88 cms), the zoo has announced, according to Live Science.

Much of the new muscle growth has come from climbing around his public exhibit at the zoo, and the panda cub appears to be developing perfectly as he continues to lose his baby fat.

Xiao Liwu has suffered no sprains or injuries so far as he tumbles around his exhibit area and learns to develop his climbing skills.

Matt Kinney, a veterinary resident at the San Diego Zoo, said in a statement: "We expect them to fall on exhibit as they learn to climb."

Kinney also explained that pandas' fur is naturally flexible and allows them to be protected from getting hurt.

He added, "When they hit the ground, they can roll out of their fall so that helps dissipate the force so he's not hitting the ground really hard like other animals might."

Xiao Liwu' mom Bai Yun, is a veteran mother, and the cub is her sixth. His name means "Little Gift."

It is likely as the cub grows stronger he will later be moved to the Chinese panda conservation and breeding program, where four of his siblings have already been transferred to.

Only 1,600 giant pandas are thought to be left in the wild, making experts at the zoo desperate to succeed in their breeding program to ensure the giant panda's continued survival.