When it comes to the physical make-up of men versus women, many of the differences are obvious. Men, on average, are 10-15% larger than women, weigh 20% more, and are 30% stronger (especially when considering upper body strength). Testosterone is one of the major hormones active in a man's body. Men also produce more HGH (human growth hormone). Testosterone stimulates muscle enlargement and bone growth and also raises the level of red blood cells in a man's blood stream.
What you may not know, however, is that all of these factors combine to make oxygen much more available to a man's cells than a woman's cells. That means a man could be working at 50% of his capacity during physical activity, but a woman would have to be working at 70% of her capacity in order to keep up. It is not as easy for her cells to absorb oxygen.
This is due partly to the fact that women have a smaller percentage of lean tissue (muscle, organs, etc.) and a much higher percentage of body fat. Though this is detrimental in a short sprint, a higher percentage of fat means that women can power their cells longer from their body's reserves without stopping to eat or drink in order to refuel. This may translate into greater endurance. Studies comparing men and women in running, swimming, and speed skating have all shown that the differences in time vs. distance decreased between men and women as the length of the event progressed.
Hundreds of studies have showed some interesting differences between men and women in nearly every area. Looking through the research, you would discover all kinds of facts such as how much more likely women are to wear a seatbelt than men (2 times more likely), to how often they are the sexual initiators in a monogamous relationship (65% of the time).
As interesting as those facts may be, let's concentrate on the differences between men and women that have an effect on women's physical fitness. These differences are primarily found in the functioning of a woman's hormones and the construction and function of her fat cells. These two factors influence everything from the way a woman's metabolism functions; to how likely she is to suffer from stubborn fat and other health related diseases such as osteoporosis.
Though the construction of the male and female fat cell is basically the same, they differ vastly when is comes to size and function. To begin with, a women's fat cell is five times larger than a man's! In addition, not only are women's cells capable of holding more fat, they are genetically programmed to do so. It all comes down to enzymes:
Lipogenic- Fat Storing Enzymes
Lipolytic- Fat Releasing Enzymes
Though these enzymes are present in both men and women, women's bodies have two times the number of Lipogenic (fat storing) enzymes, and only half the number of Lipolytic (fat releasing) enzymes. This is the genetic legacy of women's role as the childbearing and nurturing gender of the species. Nature wanted to ensure that women were carrying around enough fat cells to nurture their growing babies and to breast-feed them once they were born. A baby in-utero requires the mother to burn at least 300 extra calories a day and breast-feeding can require as much as 500 extra calories.
In addition to the normal caloric needs of a baby, our foremothers also held onto extra body fat in case of a drought or famine. This extra fat was stored in the hips, thighs, and buttocks. Therefore, the females who survived famine and drought to pass down their genes were the women whose bodies were adept at storing fat. Skinny thighs in the past were a serious liability, serving only to increase the risk of death when food supplies became scarce. These enzymes tend to be balanced in a healthy person. Too much l of either develops an unbalanced system develops and leads to insulin resistance, leading contributor to stubborn fat.
Other contributors to stubborn fat are estrogenic compounds called xenoestrogens. These chemicals are a byproduct of fertilizers, plastics, soy isoflavones, certain herbs and petroleum products. These compounds in our food and water supply mimic estrogenic functions and aid in binding to estrogenic fat receptors. This produces induced aromatase influence. Aromatase is an enzyme which helps convert androgens (male hormone) to estrogenic compounds.
When this occurs, it enhances the production of estrone, which is the main culprit in stubborn fat gain in both men and women. Look at many children today and you can see that they take on some very feminized features such as breast fat.
To benefit from a program that reduces stubborn fat, you must first recognize that estrogenic compounds are all around us (and in us). To combat this problem, you need to look at the food you consume and the liquids you drink, as there are many culprits that cause stubborn fat gain.
You move in the direction of gaining stubborn fat when you develop bad eating and lifestyle habits, which cause insulin resistance, a toxic overburden on the liver and elevated estrogen. These all contribute to the fat that will not go away. To open these cells, you should start by heading down the food chain. Minimize or eliminate all refined foods, eat plenty of fruits and vegetables (preferably organic), and exercise.
In the third and final part, you will learn more about how specifically to get this stubborn fat out of you life forever.