[quote]eatmorechicken wrote:
In order for a muscle to grow stronger, does it have to become bigger? Or can one still gain strength even if they are not getting bigger?
[/quote]
Yes, in order for a muscle to grow stronger it does have to become bigger. However, the muscular system isn’t the only system that needs to be taken into consideration when talking about strength training. The nervous system plays a huge (if not even equal) part in strength. You can therefore become stronger without an increase in muscular cross sectional area through increased neuromuscular efficiency.
But, this can only take you so far. Especially when it comes to absolute strength. Once your nervous system gets good at recruiting all your available muscle fibers, inhibiting the antagonistic muscles, activating the stabilizer muscles, etc… (basically gets good at the skill portion of the movement) then the only way that you can continue to increase in strength is through an increase in cross sectional area.
[quote]
The reason I ask is I’ve read here you can’t gain muscle and lose fight at simultaneously. You’re either eating more than you need in order to gain mass or creating a deficit to burn calories.
The reason I ask is I’m wanting to reduce bodyfat and up my endurance. (For both athletic reasons as well as for looks.) Would it be possible through weight lifting and cardio(HIIT and skipping rope) to lose fat and still maintain or even gain strength? My goal isn’t to look like a bodybuilder but just to get strong and lean.
I’m 5’9" and ~180 lbs. I haven’t had it measured but I’m pretty sure I’m somewhere in the 15-18% bodyfat range. I’ve really cleaned up my diet in the past month and I’m following the 7 rules of an effective diet. [/quote]
First, it’s pretty tough to just know where your body fat percentage is without having it tested (although if you post a picture of yourself holding a shoe we’ll be able to tell you for sure 
)
Secondly, in my opinion you’d be better off if you focused on either a performance increase, or an aesthetic improvement instead of trying to achieve both. If you goal is to improve athletic performance then the only thing you need to pay attention to is “is your performance improving”. If you choose to focus on looks, then your feed back should be more geared towards whether or not your appearance is improving.
It also seems like you’re under the misconception that an increase in muscle cross sectional area will decrease endurance. Sure, at a certain point this may be true. But, trust me being 5’ 9" 180 lbs is far from it. Just look at the WSM competitors. Those events take a tremendous amount of strength endurance, and while they probably wouldn’t win any bodybuilding contests, they certainly aren’t small guys. Another prime example are wrestlers. Wrestlers have phenomenal endurance and they are quite muscular and have a very low body fat %.
Hope this helps.
Good training,
Sentoguy