Muscles in men and women are essentially identical

A muscle fiber in a woman isn't structurally different from a muscle fiber in a man. There are some chemical differences, due to the need to interact with different hormones at the cellmembrane level, but those aspects don't change a fiber's functional abilities. We may be separate genders, but we aren't separate species. Health improves with increased strength and muscle mass, and that's just as true for women as it is for men. Consider this: In a study of elderly women who were disabled to varying degrees, researchers for the u.s. National Institute on Aging found that those with the least strength were twice as likely to die from heart disease as the strongest. The researchers on that study, published in 2003, used hand-grip strength as a measure of total strength. A University of Pittsburgh study published in 2006 looked at an additional measure of strength-testing the quadriceps (the muscles on the front of your thighs)-and found a similar effect. The weakest women had 1 .65 times the risk of death from any cause, compared to the strongest. Of course, you aren't elderly or disabled. I use those examples to prove a point: Strength has very real implications for your quality of life-your entire life. And although strength isn't perfectly correlated with muscle size (obese people tend to have a lot of muscle mass, which they need to haul the extra fat they're carrying from one room to the next) , it's a pretty good way to determine how well your muscles are working. I have two goals in this chapter. The first is to look at what we know about helping women increase their strength and muscle size, and the second is to examine the small but real differences in men and women that will affect the outcome of your exercise programs.As far back as 1 986, a study in the journal Sports Medicine asked whether women should do the same workout routines as men, and came to this conclusion: "Very little difference is seen in the response to different modes of progressive-resistance strength training. " In 1990, in the same journal, two researchers noted this: "Unit for unit, female muscle tissue is similar in force output to male muscle tissue .... There is no evidence that women should train differently [from how men dol. " Translating that into English, what the researchers are saying is that the muscles of a woman are capable of performing similarly to those of a man. Because women's muscles are smaller, a typical woman's absolute strength will be less than that of a typical man. But there's nothing a man's muscles can do that a woman's can't. The technical term for muscles ' ability to generate strength and power is "muscle quality. " But a better term for this conversation might be "muscle equality. " As in, when you control for the size of the muscles of the people you're testing, there's no important difference in the genders. Studies generally show that men are a bit stronger, muscular pound for muscular pound, but the difference falls into the range of 5 to 1 0 percent.Here's something else I'll bet you didn't know: Women and men increase muscle and strength at roughly the same rate in the same training programs. That doesn't mean a woman will gain as much muscle as a man; she'll just make the same percentage increases as her male counterpart. Let's say you have two young adults who 're relative novices in the weight room. He weighs 200 pounds, with 20 percent of that in the form of fat. That means he has 160 pounds of lean mass. The woman weighs 1 20 pounds, with 30 percent body fat. (Yeah, they've both kind of let themselves go.) So she has 90 pounds of lean mass. They both do the same six-month workout program. Since the program is designed by Alwyn, they both increase their lean mass -mostly in the form of muscle-by 10 percent. His 10 percent weighs 16 pounds, a spectacular success. His shoulders are wider, his chest muscles do a little dance when he moves his arms , and his upper arms threaten to demolish the sleeves of his golf shirts. He vows to name his firstborn son Alwyn, even though he's not quite sure how to pronounce it. (For the record, it' s " ALL-in. ") She, meanwhile, gains 9 pounds of lean mass. Her reaction is ... well, to tell you the truth, she's excited, too. That's because those 9 pounds of muscle don't look anything like the 16 pounds of muscle added by her male counterpart. Her shoulders are certainly wider, which she's happy about, knowing the straps of her sundresses will finally stay on her shoulders this summer, instead of sliding off. Her arms are a tiny bit thicker, with visible ripples in her triceps and an emerging biceps bump right above her elbow. But her thighs have only increased a third of an inch in circumference, and in exchange for that small gain in size she has quadriceps that look like they were carved out of stone, rather than fudge ripple ice cream. Her waist is actually a half inch smaller. And whereas the bulked-up man now weighs 212 pounds (having lost 4 pounds of fat while gaining four times that in muscle) , Our Lady of the Weight Room still weighs 1 20 pounds. It's not the same 1 20 pounds, of course; she's now at 17.5 percent body fat, with new curves and contours everywhere she looks. You may think I'm making up those numbers and, in fact, I am . . . kind of. The upper limit of muscle gain for women is about two and a half pounds per month, so I picked a number that was between half and two-thirds of that. And the circumference measurements came directly from a variety of studies conducted between the mid-1970s and the mid-1 990s. Some of those studies show a concurrent increase in muscle size and reduction in body fat. I can't possibly guarantee that it'll happen for you specifically-as the ads say, "individual results may vary" -but it has been shown to happen. Sometimes it happens in the exact same places. You can't call it spot reduction, where you exercise a specific region of your body with the goal of shrinking the fat in that area. (This doesn't work, as you probably know.) But, since women will tend to lose fat first in their arms and bellies during a serious exercise program, they end up exhibiting a phenomenon you could call "spot substitution"­ gaining muscle in their upper arms, for example, while also losing fat there. You can't predict or train for a one-to-one exchange of muscle for fat, but in some studies it appears to have worked out that way. One of the researchers even took pictures to illustrate the point. William Kraemer, Ph.D., probably the most influential strengthtraining researcher of my lifetime, used magnetic resonance imaging (MRI) to show women's arms and legs before and after training programs. The MRls allow you to see the increase in muscle and decline in fat after twelve weeks, with only minor changes in the girth of those limbs. Different studies have shown different results, as you can imagine. Sometimes fat decreases with no increase in muscle, which means the circumferences of the arms or legs or waist or whatever's measured will decline. Sometimes the opposite happens, and muscle increases without a loss of fat. (This is most likely to happen in the lower body, where initial fat loss is usually slow when compared to the upper body; that's why you need the combination of Cassandra's diet plans and Alwyn's workouts to tip the balance.) But in no studies I 've seen have women's measurements increased more than a fraction of an inch due to muscle gain, and in many studies everything that was measured decreased. The one exception is shoulder width. Getting stronger and adding upper-body muscle tissue will almost certainly widen your shoulders. But unless you're a runway model, it's hard to see any aesthetic or functional downside to having wider, more athletic-looking shoulders. Your neck will look longer and your waist and hips will look smaller. If anyone considers those negative consequences, it's news to me.