You sound like an ectomorph. I suggest you pick up, "Arnold Schwarzennegger's Encyclopedia of Bodybuilding."
It will talk about diet and exercise...(including weights... types,reps, angles etc...which all lead to atrophy.
Somewhere they will get into body styles. The ectomorphs code is: "Never run when you can walk, never walk when you can sit, and never sit when you can lie".
Pump up the Volume (M.A.R.S.)
Rise above the storm and you will find the sunshine ~ M.F. Fernandez