How Mars & Venus Get Fit
Part 2

Dr. Pamela Peeke was not the only scientist during the 2005 Idea World Fitness Convention to talk about the differences in the way men and women get fit. One of my favorite lecturers, Dr. Len Kravitz, spoke at length on the subject of gender differences in his presentation, “The Female Fitness Training Advantage”.

There are approximately 50 trillion cells in the body but only the reproductive cells are different in men and women. The size of an organ like the heart or liver is related to the size of the body and not the gender. Therefore, Kravitz says that you cannot distinguish an organ in the laboratory as belonging to a male or female.

It is the hormones of the reproductive system that account for the variation between sexes like height and weight.

The average woman generally has 8% to 10% more fat than a man. 5% of a woman’s body fat is sex specific meaning it is reserved for the demands of pregnancy and breastfeeding and is found primarily in the thighs, buttocks, and breasts. The body fat percentage of male and female elite athletes can vary by only 2% to 6%.

The reproductive hormones also seem to control where fat is distributed. The typical male pattern is to store fat in the abdomen and upper body while the typical female stores fat in the lower abdomen, hips, buttocks, and thighs.

Not everyone follows this stereotypical fat distribution pattern. There are women who store fat in the waist and abdomen and some males have heavier lower bodies. But again hormones seem to the cause. There is evidence that women who store fat like a man have more androgens (male sex hormones) than the average woman. Women who have much smaller waists compared to their hips have higher levels of estrogen.

Studies show that men have an easier time losing fat in the abdominal area while women have a harder time losing fat in their lower body including the lower abdomen. Fat cells have two types of receptors called alpha- and beta-receptors. Alpha-receptors inhibit lipolysis or the breakdown of fat. Women have more alpha-receptors in the hip and thigh region. Beta-receptors stimulate fat breakdown. Men have more beta-receptors in their abdominal region.

Lipoprotein lipase or LPL is an enzyme involved in fat storage. Women have 3 to 5 times more LPL in the lower body compared to their upper body. Meanwhile, hormone-sensitive lipase or HSL is an enzyme involved in fat breakdown. In females, HSL is very slow in releasing fat from the hips and thighs.

This may explain why women tend to lose fat first in the face and chin, then in the abdomen, and finally in the hips and thighs. Some experts say that a woman’s thighs will usually slim down when their body fat percentage goes down to approximately 18%.

The good news is that women burn more fat than men during low to moderate intensity aerobic exercise. This gives women an advantage in endurance sports like long distance cycling and running.

Females also have a training advantage in the sport of swimming because their higher body fat aids in buoyancy. So females have less drag and expend 20% less energy compared to male counterparts at the same pace and distance.

Men have 10 to 30 times more testosterone than women. Testosterone is the most potent anabolic hormone. Anabolic means “muscle building”. This explains why men have bigger muscles than women. Muscles make up approximately 38% of a man’s total weight while for a woman its 31%.

Testosterone helps men can build big muscles through weight training. Most women cannot. Women also have to work much harder to look “cut and defined” because they have more subcutaneous fat that covers up their muscles. Women who easily become “muscular” most likely have higher androgen levels than the average woman.

Females, in general, are 3 to 4 inches shorter and are 25 to 30 pounds lighter than males. Females are shorter because they stop growing 2 to 3 years ahead of males.

Estrogen hastens the closing of growth plates in long bones (arms and legs) thus a female has a shorter growth period. Girls usually stop growing by 18 years while males continue to grow till 21 years.

So men are usually taller with wider shoulders, more muscle mass and less fat. Women are usually shorter with wider hips and more subcutaneous fat.

Men also have more massive and dense bones than females. They have larger joints though nature has given females a larger knee joint to support wider hips. Unfortunately, wide hips also make female knees more predisposed to problems in running, jumping, and hopping.

For women with wider hips, Kravitz says that squats should be shoulder width or wider, stationary or step back lunges are less stressful than step forward lunges, and cardio activities should be low impact.

Women tend to have a greater curvature in the lumbar or lower back area, which causes them to have more problems with chronic lower back pain. So “core” exercises that teach women how to stabilize their torso when their arms and legs are in motion are a must in a woman’s exercise program, according to Kravitz.

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