There’s a difference between building strength and adding bulk. You can do the former without getting bigger, and the latter without necessarily getting stronger. What is key is that you know what it is you want to achieve.
If bulk is what you’re after, here are some key points to remember:
1. Know your max rep.
Knowing what you’re capable of is key, because you’ll need to lift about 50 – 60% repetitively to add bulk.
This will cause your existing muscle to get bigger without eating into your fat reserves or causing your body to get too lean.
Lifting more than that will eat into your fat reserves and result in a leaner form.
2. Make friends with a protein shake.
Try to consume a quality form of whey protein within an hour after your workout. This is when your body most needs to replenish its stores, and when it’s most likely to absorb the nutrients.