I am sorry but they do not say Physical Strength at all. They said "Strengthens their Rubbery Body". Strengthens their >> Rubbery << body. Which means that his Rubber Ability has upgraded. It could imply that his Physical Strength has upgraded but their wording is >> Rubbery Body <<. And lastly for Luffy it doesn't matter how if he gains Physical Strength because his ability allows him to bypass that anyways which is why Zoro trains with weights and Luffy does not.
If you have actually read my reply carefully you would have actually seen that i was saying Luffy's ability ignores Physical Strength entirely. But meh lol.
If you have actually read my reply carefully you would have actually seen that i was saying Luffy's ability ignores Physical Strength entirely. But meh lol.