Many women want to start strength training because they hear about all the benefits, but they don't know where to start, or if they are doing it correctly. Some just need the motivation of having someone else coach them or from being in a group environment.
It's important to build up to using heavier weights and/or more challenging exercises, which is essential for building lean muscle. Not to be confused with bulky muscles, which women just do not have the hormones to build naturally.
Increasing your lean muscle mass is important in many ways. For one, as you age, your lean muscle mass naturally starts to decline. When this happens, your body fat levels rise and your metabolism slows down. This can also happen as a result of dieting. If you are not eating enough calories to meet your basic metabolic needs, your body starts to use your muscle for fuel, which decreases your lean muscle mass, causing your body fat levels to rise and your metabolism to slow. This hits most middle-aged women with a double weight loss disaster. You can not healthfully alter your body composition by doing endless hours of cardio and dieting! You will ultimately be setting yourself up for failure.
You must have a balanced combination of strength training, cardio, and nutrition, to see the results that will help to improve your health, and achieve that lean, firm body that you're after.
It's also important to take regular body fat measurements to make sure you are on the right track. Why body fat and not weight? Well when you are strength training you are building lean muscle which weighs more than fat, so the scale is not the most reliable way to measure your progress. If the numbers are not moving in the right direction, you will know right away that you will need to take a look at what you are eating, and if you are sticking to the program, and make some changes from there.