Bouldering is a sport based on free climbing that is performed on small rock formations or artificial rock walls without the use of ropes or harnesses. In Japan, where the sport has become increasingly popular, the most popular type of bouldering involves artificial rocks and boulders fitted with protrusions called "holds" providing the required resistance to climb.

Those who compete as bouldering athletes are usually very muscular since they need to train their bodies to hold their body weight.

Bouldering is so popular in Japan that even cats are getting into it:

This is a picture posted by Twitter user ミルフィーユ丼 mirufīyudon showing his cat boldly climbing up a bouldering wall.

Making full use of its long torso, the flexible feline clings to the holds. If you didn't know otherwise, you'd think the cat was a natural.

The cat's bouldering prowess elicited comments such as, "He's got a strong back," "He's got the muscles of a trained athlete," and "He must have been a mountain cat in a previous life."

According to the cat's human, he's only been bouldering a few times before.

Maybe he only does it when he's up for a good challenge...