https://www.livestrong.com/article/80930-gain-pounds-muscle-months/

Intervals

Perform this workout 3x or more a week (ex: Monday, Wednesday, and Friday)

Low Reps -> Power
Medium Reps -> Muscle-growth (9 - 12)
High Reps -> Endurance

Stop each exercise at the point of positive failure.
Example: if you can complete 12 reps with 135 pounds on bench presses, increase the weight by 10 pounds for your next set.

Excercises

Compound mass movements for each muscle group then ollow each compound movement with one or two sets of a contraction exercise for that muscle group:

Bench presses -> chest
Lat pulldowns -> back
Upright rows -> shoulders
Decline close-grip bench -> triceps
Barbell curls -> biceps d
Squats and deadlifts -> legs.

Dumbbell flies -> chest
Under-grip lat pulldowns -> back
Lateral raises -> shoulders
Kickbacks -> triceps
Concentration curls -> biceps
Leg extensions & curls -> legs (quadriceps & hamstrings)

Diet

5-8 meals

  • 20-30g of protein (4-ounce roasted chicken breast gives you just over 25 grams of protein)
  • 1 serving of low-glycemic carbs (oatmeal, brown rice, sweet potatoes, whole-grain bread, pasta, fresh fruit)
  • 1 serving of healthy fats (flax seed oil, avocado, peanut butter, olive oil, nuts+seeds, egg yolks)

Drink a post-workout protein shake

  • 50g of whey protein.
  • 100-200g of carbohydrates, such as fruit juice.
  • 30g healthy fats, such as flax seed oil or medium-chain triglycerides.

Drink two shakes per day: 1 scoop protein, 1 pint fruit juice, 1 Tbsp oil