Say you exercise alot and weight train, is the Metabolism that you increased in speed permanent or not? Like people who are born as Ectomorphs have a permanent fast metabolism, at least..until they get older.

No... it doesn't really change your "body type". That classification is just to give you an idea of what you need to do to work with your body, as opposed to taking general advice that may not work for you. Whether you gain fat easily or you gain mass with extreme difficulty, you will be fighting that condition probably your whole life, at least to some extent.

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Keep your body lean, your blood clean and your mind sharp. -Rollins