Hi Coolpari! I do not have enough time to lay out an entire training plan but I can provide some basic knowledge to help you along. First, I used to be considerably under weight and I used bodybuilding to increase my weight. I began at 132 pounds and eventually got up to 180 pounds. I learned a lot during that period about what works and what doesn't.
You can either increase muscle or increase fat and since muscle looks good, I will assume you want more muscle.
People who need to gain weight often have a fast metabolism. That means you should adjust your exercise to limit the number of calories you use during exercise and adjust your diet to increase lean body mass.
Your exercise should include your weights but you should do short, intense work outs instead of long workouts. You will get better results by training 3 or 4 days a week at the most and resting as much as possible on off days. And it is best to do basic exercises that use a lot of muscle such as squats, lunges, presses, and rows etc using heavy weights.
Diet is a huge obstacle for people under weight because they naturally don't eat enough to get fat. If they are available where you live, creating a protein shake is probably the best way to introduce additional food into your diet because liquid digests easier so they are less likely to interfere with regular food intake. Try a good quality whey protein a couple times per day between regular meals. Start small and work up, meaning just add the protein to water at first. You can gradually increase the calories by using blender to make higher calorie nutritious shakes once your body gets used to the new food by blending in a banana and/or milk or juice, later some yogurt and banana, and later peanut butter.
I did this by making a shake either the night before or in the morning and drinking half of it between breakfast and lunch and the other half in the afternoon.
One last thing: just like trying to lose weight--don't look for quick results--results take time
Good luck!
