He studied at Kadambathur Government higher secondary school and then worked with Southern Railway in Chennai.

Initially interested in Kabaddi, Karunakaran took to weightlifting to gain strength and power at age 17.

Two years later he won another gold at the Commonwealth weightlifting championship and broke 6 international records in Cardiff, Wales.

Thereafter he took part in competitions in New Zealand and the Commonwealth Games in Brisbane, Australia; where he carried the Indian Tricolor.

Karunakaran captained the Indian weightlifting squad to the World Railways Meet in Bulgaria in 1984 where he won a bronze medal.