Arnold Schwarzenegger was 21 in Hercules in New York when he played the character 'Hercules'.
That was over 54 years ago in 1970.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 76, and has starred in 130 movies in total, 127 of those since Hercules in New York was released.
In Hercules in New York, I think Arnold Schwarzenegger looks: