How do you gain weight by lifting weights?

Answer:
Exactly as you said: by lifting weights. Regardless of what type of weight-lifting program you are following, lifting weights will (and should; if not, increase the weight/reps) will increase muscle size and ultimately lead to a heavier weight.
Contributor: Derrick
First answer by Squirrel Man. Last edit by Squirrel Man. Contributor trust: 2061 [recommend contributor recommended]. Question popularity: 4 [recommend question].