Numb/tingly hands while cycling

[PamNY]

My hands are starting to bother me -- I never had much problem before. I have gloves and might or might not wear them. Never seemed to affect me much one way or the other.

Same bike, same routes, same distances as usual. My bike is a Trek fx series, so I lean forward a little, but not as much as on a road bike.

I have been lax about upper body and core exercise lately. Is it reasonable to suppose that I'm weaker and therefore leaning harder on my hands without realizing it? Anything else I should consider?