Martinez was born and raised on a ranch in Salinas, California. At a young age, Martinez would strength train under a tree with a non-revolving exercise bar and weights. He would tie some of these weights on the bar with just a rope so that they would stay on while he would lift. Martinez was so strong that he eventually began bending all of his bars because of all the weight he load on. He would then take a hammer and bend the bars back into place to straighten them and continue on with his training.
Martinez's lifting career in Olympic weightlifting lasted for over 23 years. Throughout his career, he earned himself 10 national championships, 3 olympics including a silver medal and a 4th plave finish, 3 Pan Am medals, on top of being the first American to snatch over 400 lbs. and clean & jerk over 500 lbs in competition. Martinez had very rough training techniques. He was well-known for his bent-arm pulling style. When he would rack his cleans, only his finger tips would be on the bar and he had to regrip for the jerk. When his hands were to slip off, he would have to grab the bar again.