gaining muscle during calorie deficit?

Erm...huh??? No, your body changes as you lose weight and gain muscle. A pound of fat is the same weight as a pound of muscle, but the pound of muscle is leaner.

If people do NOT exercise, they likely will not build muscles as they lose. But if you do exercise, even if you don't lose weight, you still build muscle somewhere along the way.

Here's an article about it:

http://www.gain-weight-muscle-fast.com/lose-fat-gain-muscle.html

In studies that have been done, people in calorie deficit lost lean muscle mass. However, if they do strength training, they didn't lose as much strength as people who dieted and didn't strength train.

So doing strength training is still a good thing to do while dieting, even if doesn't mean you will be gaining pounds of muscle.

It depends on your muscle building goals I think.

As Brenda said, if you want to really bulk up, you need calories to do that. I don't think you will find anyone to contradict that statement.

But, if you are eating a healthy diet, your body is getting the nutrients it needs. If you are in a calorie deficit you are not getting all the calories you need, so your body will burn fat to make up that difference.

Adding lean body mass is, for almost anyone, not a rapid process. Muscle builds slowly. Every time you exercise your body makes adjustments to make you stronger for that exercise in the future. That comes from increases in muscle as well as increases in capillaries to feed oxygen to those muscles. The next day you are always marginally better for having done some exercise, no matter what shape you are current in.

You can lose fat and build muscle, if you have realistic goals for both. I ride my bike to/from work every day and do weight lifting two nights a week and run on a treadmill two nights a week as well. I could not do any of that when I started losing weight, but while losing and exercising I have been building muscle and increasing cardiovasclar health. It didn't happen overnight, but it did happen.

Muscle weighs more then fat. SO 5 lbs of fat mass is huge compared to 5 lbs of muscle and muscle burns 50 calories per pound while fat is 2 calories per lb. It is really hard to put on muscle without some sort of weight resistence training and eating lots of veggies, fruits and at least 6-9 oz of protein per day. Just like the big Rhino that eats grass but his genetics allows him to get big well your genetics plays a huge rule. But just because a women is big does not mean she has much muscle mass. :noway:

I'm probably on the verge of doing it, but I'm a genetic freak.

For the last 4 months I've been on about a 500 calorie a day deficit and eating most of my exercise calories. I have maintained my weight within a few pounds, and gotten measurably more muscular - not just in terms of definition, but in terms of actual measured size (bicep & chest). I have lost significant bodyfat (measured waist) which has led to muscular definition I've never seen before.

I realize that I'm probably not really in calorie deficit at all. Logically, if I was, I'd just about have to lose weight. As Sweetie said " You can't have excess energy at the same time that you don't have enough energy. ". My BMR is probably lower than MFP's estimate, so my "Deficit" food intake is actually meeting my needs.

When the crew of The biggest loser gets all "Rocky IV" on you with the testing and the meters and the blood work etc. etc. then you'll know exactly what your picture looks like. But until then we have to go by estimates, and in my case I think MFP's estimate was a little off. Maybe yours is a little off too.

Interesting stuff...

Yep. You don't get "abs" by building your abdomenal muscles - though that will help a little. You get abs by losing the blanket of bodyfat that was obscuring your abdomenal muscles.

You're probably not getting bigger muscles - very hard for a female to build a lot of muscle mass (it's a hormonal thing, sorry). You're probably losing a layer of bodyfat - and removing that fat is making your muscles more visible.

You're also getting stronger and more toned & fit - and that's fantastic. But "Toned" is not "Bigger",,, two different things.