Its all broscience, you cannot cover up gynecomastia. Look at a member from the UK who's just had surgery
https://www.gynecomastia.org/smf/20/my-story-raising-the-cash/105/
scroll down to the second post, and thats what gland looks like. No amount of lifting weights will cover up gland and generally people who think there can be having been lied to by reading misinformation on body-building forums. Im not saying this to dishearten you, but the gym isnt the answer im afraid.
Hey, are those my burgers you're talking about?
As you can probably guess from my photos, I've never set foot in a gym! - but around 15 years ago in my mid-20's I did diet to the point of being seriously thin, too thin, people said I looked really ill and were genuinely concerned about me - but still the moobs remained almost unchanged. I say almost, as in actual fact because every ounce of the "normal" layer of fat went off my chest and torso, if anything they were even more pronounced, very pointy and cone-like.
Once I realised for myself they definitely were not fat, I put weight back on again, and for most of my life have been 30-50 lbs over "ideal weight" - and with a bit of fat on the chest it actually smoothed the contour out so that nipples were not so pointy, just more of a fuller chest shape. With a little bit of belly too, shirts sort of hung OK and disguised the problem as good as was ever going to be possible. Still never wore a t-shirt, only button-up shirts with double chest pockets on them, and usually checked or striped or very heavy fabric like denim.
3 years ago I started to seriously research surgery options, and started saving hard in October 2011. over last summer I brought my weight back down to 11 stone, which is about right to me, and have maintained it there since. In a few weeks time when healing is advanced enough, I hope to start toning up a bit.
When I saw the photo of those two huge piles of nasty tissue Mr Levick had cut out of me, and that there was almost zero fat in the liposuction jar, I felt fully justified in having surgery, as there was clearly no other possible way I was ever going to get rid of those damn moobs. The miracle, still, is how on earth he managed to get that much meat out of two tiny little slits in my armpits! - the man is a genius.
I'm updating my thread with daily photos at the moment, so you can follow recovery progress if interested - click link in my signature
Good luck!