Contrary to popular belief among women,women are unable to naturally produce enough testosterone (one of the main hormones responsible for increasing muscle size) to build huge muscles. Unfortunately, the image that may come to your mind is that of professional female bodybuilders. Most of these women use anabolic steroids (synthetic testosterone) along with other drugs in order to achieve that high degree of muscularity. In addition, most also have good genetics coupled with an unbelievable work ethic that enable them to gain muscle quickly when they spend hours in the gym lifting very heavy weights. Believe me when I say that they do not look like that by accident. (see pic to left)
Women who conduct weight training without the use of steroids (see picture to right) get the firm and fit cellulite-free looking body that you see in most fitness/figure shows these days. This is the level of muscle mass a woman's body has the natural ability to build. A study published in the Journal of Strength and Conditioning Reseach showed that pumping iron two times a week can decrease back pain by 18 percent after 16 weeks and by 42 percent if you’re strength training four times a week. More research has found that just 30 minutes of strength training two to three times a week can improve cholesterol and blood pressure numbers, increase bone density and speed fat loss.
Another factor that seems to deter women from being interested in weight training is weight gain. Most women want results that show in numbers when they step on a scale. Unfortunately, muscle weighs more than fat, so if you lose 4 pounds of fat by weight training, and build 3 pounds of muscle, your scale isn't going to show much improvement.
Before I started weight training I was "skinny fat". I weighed 120 pounds, but my arms, stomach, and thighs were soft and fatty. Think lighter is better? Think again! Once I learned about proper weight training, and pushed myself hard, I GAINED about 13 pounds. I'm 5'4" and my weight now fluctuates between 130 and 135 pounds. My body is firm and toned. My stomach is flat, and even on days that I feel bloated, I have abs. (To the left is a picture of me from August 2011 @ 133 pounds)
My advice is: Get rid of your scale! It's not an accurate way to judge how much fat you are losing because the scale wont tell you that you weigh the same because you lost 2 pounds of fat and put on 2 pounds of muscle! It just tells you that you haven't lost any weight! Now isn't that a sure way to kill your feel-good buzz!
If you are looking to do some serious fat loss, my recommendation is to weigh yourself your first day of training. From then on... NO MORE than once a month! Focus on your mental and physical body changes. Are you physically stronger? Are you mentally stronger? Are parts of your body firming up? Do you feel lighter? Do you feel healthier? These are the questions it's important to ask yourself!Also, weight training creates tears in your muscle fibers, and to help fuel muscle repair (protein synthesis) your body stores glycogen and water in your muscle tissue. A potential downfall is that you may appear fuller, or slightly larger post workout due to this storage. Know this: It's in fact muscle mass making you appear fuller, not fat. If you watch your waistline to a T, this could cause some frustration and make you wonder "How can my pants be tighter when I've been working so hard?" Trust me, it wont last.
A girl friend of mine complained to me that her pants felt tighter after weight training for a week than before she started weight training at all. She wanted to quit. I had to explain to her that even though she couldn't see it yet (because she still had a great deal of fat in her midsection) her body had produced muscle mass underneath the fat, which was maker her feel fuller.
Within a couple more weeks of dedicated weight training, my girl friend who at one point was ready to give up, was holding her pants out from her waist with about a 4 inch gap. She was down 2 pant sizes! Even though her weight had only dropped about 5 pounds (because she had built heavy muscle tissue), the physical results were very noticeable. Her body was firmer, and she was noticeably thinner.
My advice is: Give weights an honest try! Don't let this temporary size adjustment deter you from continuing with weights! I promise you, if you are working hard, it is purely TEMPORARY! Your hard work will pay off!
3 More Reasons to Start Lifting:
1. You Don't Have To Plateau – To build strength, muscles need to be challenged to the max. And while yoga can be strenuous, it has its limits. Although using only your body weight can be challenging when you first start doing yoga, your muscles quickly adapt, so the benefits diminish over time. But when you lift weights you can keep taxing your muscles and get stronger gradually increasing the amount of weight you lift. 2. It Revs Your Metabolism – Your metabolism is the rate at which your body burns energy, or calories to function. Weight training causes tears in your muscle tissue (as I mentioned before) and repairing them (through protein synthesis) with the use of stored glycogen is a highly draining task for your body. When I say "draining" I mean "uses energy", and essentially energy comes from glucose, which is also stored as fat.
So even while you're fast asleep long after a workout, your metabolism is still revved at a high gear working to repair muscle tissue, and when your body runs out of glucose from the food you have recently consumed, it taps into your stored energy, which is FAT! 
