The main factors for an extended life , I do believe, are partly in the genes; number two is life style, including balanced diet and standard exercise. I walk, work and swim every day. However, I believe a lot of workout is also harmful because of over-stress; often people who workout too much time daily die early.
The great issue about’Arrow’is we never state never on the show. Ideally the show can have a great extended life , and all manner of things can potentially happen.