Workout Routine (Hard Gainers):

* Intense lifting: machine weights, bodyweight (Calisthenics) whatever suits you; increase reps as you gain.

My Calisthenics Workout Routine:
Arms & Back - https://youtu.be/_9bXjKFDT64 & https://youtu.be/RTF4ADblouI
Chest - https://youtu.be/_q_-adYzkh0
Legs - https://youtu.be/1JjuaKI1W-U

* Eat A LOT. You might think you already do but you prolly eat 2 big meals a day. Eat like 4. Or just eat in small Increments often. Eat foods heavy in protein. Try to take it at least 60g of protein a day or more for noticeable results. Protein shakes help A LOT. Aim for 2500+ calories a day, depending on how much you want to gain weekly.

* Do cardio once a week (or twice) don’t do too much bc ur goal is to gain muscle, too much cardio burns off the muscle you gain and makes it hard to gain weight. Workout moderate/intense 4-5 times a week for 1 hr. let ur body rest for 1-2 days and get back to work.

* Eat healthier, lots of fruits and veggies, home cooked meals, high protein low carb diet. stay away from fast food. Every once in a while is ok but it fucks with your mood and health over time.