Arnold Schwarzenegger and his teenage son Joseph Baena spent some time bonding at a gym on Thursday.

The 69-year-old action star was pictured leaving Gold's gym in Venice, California with his 18-year-old lookalike son in tow.

Donning a red Team USA t-shirt the Terminator actor looked proud as punch to be joining his offspring for a post-workout bike ride.

Pumping iron: Arnold Schwarzenegger and his son Joseph Baena were spotted leaving Gold's gym in Venice on Thursday

And having the iconic movie muscleman as his fitness mentor has clearly rubbed off on Joseph as the student showed off his impressive arm muscles in a red tank top.

After pumping some iron the former Governor of California was roped into taking a selfie with an eager fan outside the famous gym.

However once they got pedaling the twosome looked in great spirits and enjoyed a leisurely cruise around the beach city.

California boys: The duo coordinated in red as they cruised around the beach town together

Like father like son: Having the iconic movie muscleman as his fitness mentor has clearly rubbed off on Joseph as the student showed off his impressive muscles in a red tank top

Joseph is the Terminator star's child from an affair he had in the 1990's with his housekeeper Mildred Patricia Baena, known as Patty.

The actor was married to Maria Shriver at the time it occurred and Patty fell pregnant with Joseph in 1997.

It only came to light that the action hero had fathered a love child in 2011, when Maria, 60, ended the marriage and moved out of their home.

The actor himself was unaware he was Joseph’s father for many years, and told 60 minutes that it wasn’t until the boy 'started looking like me, that's when I kind of got it. I put things together'.

Standing out: The 69-year-old actor donned a red Team USA t-shirt and grey shorts

Arnold and Maria have four children - Katherine, 26, Christina, 25, Patrick, 22, and Christopher, 18, who was born just five days before his half-brother.

Their divorce is yet to be finalized.

Meanwhile the Predator star has been keeping busy recently filming Why We're Killing Gunther.

He was spotted on the set of the Taran Killam-directed comedy in Vancouver earlier this month.

Popular patrons: Arnie was roped into a selfie with a fan as the duo prepared to head out

Family time: Joseph is the Terminator star's love child from an affair he had in the 1990s with his housekeeper