Arnold Schwarzenegger is ''very happy'' his son is following in his bodybuilding footsteps.

The former Mr. Olympia's 21-year-old son Joseph Baena - who he had with former housekeeper Mildred 'Patty' Baena - is keen to compete in a classic physique competition and the Hollywood star would be delighted to see it happen.

He told Extra: ''He's very serious about it and I'm very happy about it because I said to him, 'It's important to take care of your body, train hard, if you're passionate about that, but also study hard, because the key is to get your business degree at Pepperdine.'''

Although Schwarzenegger wants Joseph to make sure he gets an education, he is also supportive of his bodybuilding ambitions.

He added: ''Yeah, yeah, he is very serious about this whole thing. He wants to compete in one of the classic physique competitions ...

''He's training very hard ... I'm a big believer in also training for strength ... I put it on 455 and he did two reps. I saw him do one and I was like, 'Go for the second one, Joseph...'''

The 71-year-old actor has also praised Chris Pratt, the Hollywood actor who is engaged to his daughter Katherine.

He said: ''He's a wonderful guy. They both look really great together, they're both happy together, so I wish them both the best of luck.''

Meanwhile, Chris - who has a six-year-old son called Jack with his ex-wife, actress Anna Faris - recently admitted he wants to have ''lots of kids'' with Katherine.

Asked about his future plans and ambitions, Chris said: ''The future? Oh ... Lots of kids. Maybe less time spent working, more time spent enjoying life.''