Ive had many people tell me that in order to get big you must get strong first. Is this true? My main goal is gaining size. So ive been doing a 3 day a week full body routine with decent results, which was recommended to me. Im 6 2" 175 lbs. Im not really that strong yet, but dont care that much.
Muscle is built by stimulating the body with progressive resistence and supplying it with raw materials by eating a caloric surplus. Fact: progressive resistence will make you strong.
You will get bigger while getting stronger if you eat enough, size and strength go hand in hand. You should always be trying to get stronger whether it be weight lifted or reps anyways.
Think of it more like a figure of speech rather than literal advice. It's not like: Step One: Gain Strength. Step Two: Gain Muscle. If your goal is to "look more like a bodybuilder," 9 times out of 10 you should get bigger while also getting stronger.
Let's say six weeks goes by and you've gained strength without gaining size, it means you haven't been eating enough. On the other hand, if time goes by and you've been gaining bodyweight without increasing the weights you're lifting, odds are you're adding more fat than muscle, which we don't want.
Not to sound like a dick, but i was 6'2" and 170 in high school and that's still very skinny. Please define "decent results".
How much bodyweight have you gained in the last eight weeks.
I know you said you're "not really that strong", but what are your current best lifts in the squat, deadlift, flat bench press, overhead press, row, and pull-up/pulldown?
It is true that you make a muscle bigger by making it stronger (if your nutrition is enough to support growth), however that does not mean you must powerlift in order to build your muscles.
There is a difference between moving a great weight from point A to point B, and stimulating a muscle with a great weight (and that difference is going to look like two totally different people).
If you want to take bodybuilding very seriously and see real significant results, then I suggest you stop with the 3x/week fullbody foo foo routine, and start doing a traditional bodybuilding routine... and get help from this forum on creating a bodybuilding diet.
I will also say that you need to create serious, and specific goals for yourself if you want to make progress. "I want to get bigger" is not a goal. For example, "I want to be 200lbs with 17 inch arms and a 275lb bench/squat" is a goal, and something you can create a plan to achieve.
You won't get bigger without forcing your body to get stronger. Your body adapts to deal with the stresses you place upon it. If you don't force it to get stronger, why would it need to get bigger?
It's really more of a mental cue, I think. Like ripping the bar apart when you bench. You're never going to rip the bar in half, but it helps you get your mind right.