However, you may not be aware of our research studies that led us to this conclusion. In fact, you may have heard that women should not do strength exercise for one of the following reasons.

(1) Strength training makes women too muscular and bulky.

(2) Strength training is a waste of time for women because they are not capable of developing strong muscles.

(3) Strength training is dangerous for women because their bodies are not designed to exercise with resistance.

Of course, none of these reasons is valid and such misinformation is incorrect. Actually, very few women have the genetic potential or enough natural testosterone to develop large muscles. Firm, fit, functional muscles, yes-large muscles, no. On the other hand, women most certainly can achieve high levels of muscle strength. In fact, our studies show that females develop muscle strength at the same rate as males, and on a pound-for-pound basis are equally strong. Finally, it is ridiculous to think that women's bodies are too frail to perform resistance exercise. After all, what physical activity is more demanding than childbirth?

To clarify some of the above statements let me share some of our research findings. In one of our largest studies, with over 900 male and female participants, we tested the leg strength of both genders. In terms of actual weight lifted, the men were 50 percent stronger than the women. However, the men also were, on average, 50 pounds heavier than the women. We therefore decided to compare leg strength relative to the individual's lean body weight. On a muscle-for-muscle basis we found essentially no difference in male and female leg strength. Both genders performed 10 computer-monitored leg extensions with 75 percent of their lean body weight. Other researchers have attained similar results, and no scientist can distinguish between male and female muscle tissue under the microscope, because there is no physiological difference.

Over the past 15 years, we have performed dozens of research studies and taught hundreds of classes with women strength trainers of all ages (children, teens, young adults, middle agers, and seniors). To date, not one participant has complained about becoming big or building too much muscle.

Remember, women who do not strength train lose about 5 pounds of muscle every decade of adult life. That leads to a lower metabolism and a gradual increase in fat weight (about 15 pounds per decade), as well as a less fit, firm and attractive appearance. So, in most cases, the added muscle simply replaces the muscle previously lost through lack of use. And women who start strength training typically lose twice as much fat as they gain muscle. In one of our studies, more than 700 women performed about 25 minutes of strength training (13 Nautilus exercises) and 20 minutes of aerobic activity (treadmill or cycle) 2 or 3 times a week for two months. On average, they added almost 2 pounds of muscle and lost about 4 pounds of fat. They also increased their muscle strength by over 40 percent, which greatly enhanced their physical abilities and performance levels.