My little 200 pound oinker...DOOODOOOoooooooooooooooooooD.
I spent 11 years in broadcast news, so I often speak to a wide audience, and not just the poster as an individual,...just to clear that up.
Mayo has done some great anti-aging research, on how androgens protect the heart and protect you from diseases of aging. I've posted those elsewhere on this site, but, you can google on anti-aging and mayo and read all about it. It's not right that you were mislead.
With regard to hitting it harder: that's poor advice. It drives your androgens and recovery down. National Geographic recently did a program that talked about the perils of over-training.
If you want to stay anabolic (growing), you need to stimulate, but, not overtrain. Overtraining can make you go highly catabolic (losing), and hitting it harder, without proper caloric intake, and without enough androgen, can be highly detrimental to your training goals. If you train like an idiot, you'll look like one, too.
Most folks don't realize the intensity of resistance training on their body. Stimulate, eat, rest / recover. Guys use androgen not just to feel better, avoid disease, have improved sexual function and cognitive ability but also and certainly the reason athletes chose to use science in such a way is ...to change the rules of recovery. If you're not 18, and you aren't eating enough, and you are not anabolic...you'll lose ground by overtraining. That advice was not sound, and would be detrimental to your overall goals.
Again: more is NOT better. Don't be an idiot. Stimulate; eat; recover. If you aren't eating enough, or aren't anabolic for whatever reason, more training will only slow you up.
Speaking to the poster, if you can train yourself to eat, or...and listen closely, there's nothing wrong with being thin. Without calories, though, lifting is nice way to stay firm, but, you won't gain without the calories. I literally eat until it hurts, and then, eat extra. I don't get fat, because I carry so much lean muscle, and I weighed 175 in high school at 12%. I look at weights and grow, and I vacuum food in. Just how I am. A machine. You can buy weight gainer, and so on, but, there's no real substitute for real honest food. Eat, if you want to gain. You'll get used to eating if that's what you want.
dood has gained 60 pounds by following his diet to the letter. He stuffs it down, in much the fashion I do. He wants it, and that's what it takes. He's also type 1 diabetic, and insulin dependent and is able to keep himself anabolic through smart insulin management.
Carbs, and insulin management, along with proper protein, are how you make gains. It's really not rocket science in the way that some would think.
I've seen many a collegiate football player gain 60 to 80 pounds on beer, pizza, fast women / guys, the training table, and intervals (suicides).
Whatever it is you seek, you should like doing it. That makes it easier.
I like eating. I like lifting. I like looking as I do. I love working out at high intensity. I've been doing it 33 years now. Find what works for you, and have fun with it.