Studying and playing go hand-in-hand. How much you should study will depend on how well and how far you want to get. For example, I don't plan on playing higher than the $2 mtts (maybe a few shots at $3-$5 mtts), so I don't need to study a lot of mtt strategies for mid buy-in (or higher) games because it just wouldn't apply to me as much. At the same time, I need to make sure I know how to beat my opponents at my current level.
On top of studying, knowing how and when to apply what you've learned is also crucial. It doesn't make sense to learn how to do something but never apply it. So, part of studying and playing is being able to apply what you know. I also think it helps with figuring out your own style and strategy as well, because not every strategy is going to be a one-size-fits-all deal. So, knowing the hows/whys of strategies and knowing how to apply a bit of everything to your own approach to the game.
To give an example, someone playing 15 $1 mtts a day, multi-table 3-5 mtts at a time will have a much different strategy than someone playing 3-4 $1 mtts a day, 1 table at a time. At the core, the basic strategy might be the same but individual strategy will differ and it's good to figure out what works for you in your situation. These are both me. I had to adjust my own strategy and how I approached the game, it's different levels, etc in order to do well. My strategy changed compared to my previous days of playing when I played a higher volume and because of that, while at the core my general strategy stayed the same, I had to make adjustments in other parts in order to do well.