Doubling it naturally? Only way that is possible is if you were below baseline and trying to recover. Then yes, you could double it. Under normal circumstances well within the normal range however? I smell bullshit.
''Relax, smile and dont ask anything. Just buy my book'' - Rob Lipsett
His 5 Proven Methods are just nothing else but principles what an every person working out should be focusing on. Recovery, well balanced diet, good training regime and stress management thats all you need to keep good level of tetsosterone.
His testosterone went up because he gained more weight-body fat. Thats it.