Arnold Schwarzenegger’s son Joseph Baena rings in his 26th birthday with video of him in Speedos at the beach

Arnold Schwarzenegger’s son Joseph Baena marked his 26th birthday with a hunky video shared to Instagram.

The fitness enthusiast — whose half-brother Christopher Schwarzenegger also just turned 26 — celebrated his special day by hitting the beach in a Speedo.

The buff actor wore nothing but a pair of teeny black briefs as he took a dip in the ocean before running through the sand.

The star’s rippled abs and chiseled arms were on full display in the seconds-long clip posted for his 539,000 followers to see.

He wrote in the caption, ‘Twenty Six? More like Twenty SICK! Here’s your POV of me running into my late twenties,’ adding a crying laughing emoji. 

Less is more: The fitness enthusiast — whose half-brother Christopher Schwarzenegger also just turned 26 — celebrated his special day by hitting the beach in a Speedo

The post quickly collected thousands of likes from Baena’s digital fanbase.

Despite the overcast day, the gym rat was all smiles as he participated in a fitness circuit with others.

Written on one of his brawny biceps in black marker was the number 743, indicating his status in the event.

He also wore a red anklet as he joined others sprinting through a large, red finish line arch.

Later in the day, the multihyphenate took to his Instagram Stories to share a gym selfie.

He wore a faded black T-shirt, black athletic shorts, long white socks, and a pair of brown and white checkered slip-on Vans sneakers. 

Posing in a tall mirror, he smiled with his mouth shut and wrote, ‘BDay pump,’ with a green check mark emoji.

The posts come one day after the buff DJ shared that he completed his first triathlon.

Wow: The buff actor wore nothing but a pair of teeny black briefs as he took a dip in the ocean before running through the sand

Excited: He wrote in the caption, ‘Twenty Six? More like Twenty SICK! Here’s your POV of me running into my late twenties,’ adding a crying laughing emoji

Routine: Later in the day, the multihyphenate took to his Instagram Stories to share a gym selfie

Following in dad’s footsteps: Arnold’s son Joseph Baena has taken to bodybuilding and acting, just like his father

He uploaded a smiling snapshot of himself standing on the beach and flexing one of his impressively sculpted arms.

In a satisfied caption, he wrote, ‘Competed in my first triathlon today! What a great experience it was to compete with such amazing athletes. 

‘With my birthday coming up I wanted to challenge myself in a new way, I feel like I did really well and I’m proud of myself for going the distance. I truly believe that if you have muscles, you should be able to use them!’

Joseph is Schwarzenegger’s love-child, who was born after the actor had an affair with housekeeper Mildred Patricia Baena. He has taken to bodybuilding and acting, just like his father.