Interesting, thanks. I did do a basic consumer blood test which reported my testosterone as "normal" (whatever that means), but I should probably do a more in-depth one and check these things.
^ has information on why 'normal' isn't a good range for everyone.
> The Art of Manliness participates in affiliate marketing programs
Seems like a terrible resource. Much better would be blood work at your PCP (and a possible referral to an endocrinologist).