Weight training expert and researcher Wayne Westcott, PhD, from the South Shore YMCA in Quincy, Massachusetts, gives 10 important reasons why women need to take strength training seriously:

You'll Lose More Fat Than You'll Gain in Muscle. Westcott and his colleagues have done numerous weight training studies involving thousands of women and have never had anyone complain about bulking up. In fact, Westcott's research shows that the average woman who strength trains two to three times a week for eight weeks gains 1.75 pounds of lean weight or muscle and loses 3.5 pounds of fat. Unlike men, women typically don't gain size from strength training, because compared to men, women have 10 to 30 times less of the hormones that cause bulking up, explains Kraemer.

Your New Muscle Will Help Fight Obesity. As you add muscle from strength training, your resting metabolism will increase, so you'll burn more calories all day long, notes Westcott. For each pound of muscle you gain, you'll burn 35 to 50 more calories daily. So, for example, if you gain three pounds of muscle and burn 40 extra calories for each pound, you'll burn 120 more calories per day, or approximately 3,600 more calories per month. That equates to a loss of 10 to 12 pounds in one year!

You'll Be a Stronger Woman. Westcott's studies indicate that moderate weight training increases a woman's strength by 30 to 50 percent. Extra strength will make it easier to accomplish some daily activities, such as lifting children or groceries. Kraemer notes that most strength differences between men and women can be explained by differences in body size and fat mass; pound for pound, women can develop their strength at the same rate as men.

Your Bones Will Benefit. By the time you leave high school, you have established all the bone mineral density you'll ever have-unless you strength train, says Westcott. Research has found that weight training can increase spinal bone mineral density by 13 percent in six months. So strength training is a powerful tool against osteoporosis.

You Will Reduce Your Risk of Diabetes. Adult-onset diabetes is a growing problem for women and men. Research indicates that weight training can increase glucose utilization in the body by 23 percent in four months.

You Will Fight Heart Disease. Strength training will improve your cholesterol profile and blood pressure, according to recent research. Of course, your exercise program should also include cardiovascular exercise and flexibility training.

You Will Be Able to Beat Back Pain and Fight Arthritis. A recent 12-year study showed that strengthening the low-back muscles had an 80 percent success rate in eliminating or alleviating low-back pain. Other studies have indicated that weight training can ease arthritis pain and strengthen joints.

You'll Be a Better Athlete. Westcott has found that strength training improves athletic ability. Golfers, for example, significantly increase their driving power. Whatever your sport of choice, strength training may not only improve your proficiency but also decrease your risk of injury.

It Will Work No Matter How Old You Are. Westcott has successfully trained numerous women in their 70s and 80s, and studies show that strength improvements are possible at any age. Note, however, that a strength training professional should always supervise older participants.

You'll Strengthen Your Mental Health. A Harvard study found that 10 weeks of strength training reduced clinical depression symptoms more successfully than standard counseling did, Westcott says. Women who strength train commonly report feeling more confident and capable as a result of their program.