A man's leg is about 80 percent muscle, compared with about 60 percent muscle in a woman's leg, Kraus said. That extra muscle can help men run faster, she said. Also, men's muscles tend to have larger fast-twitch muscle fibers, which help with sprinting, than women do, Kraus said.
Summary: Conventional wisdom holds that men run 10-12 percent faster than women, regardless of the distance raced. But new research suggests that the between-sex performance gap is much narrower at shorter distances.
Because men possess a larger aerobic capacity and greater muscular strength, the gap in running performances between men and women is unlikely to narrow naturally.
Meanwhile, when girls start going through puberty at 11.5 years, they increase in fat mass and their hips widen, which can substantially affect their running performance in the years following puberty.
Furthermore, the performance on each sprint phase is uniformly affected by the chronological age. Boys run faster than girls in all running phases, and the span between genders increases after the age of 15 years.
Boys become stronger from puberty on, which positively influences the rate of limb movement and speed.
This change in performance occurs inconsistently and is not always related to training factors. Female runners need to be aware that as the human body physically matures, many adolescent athletes note a decrease in performance.
A woman who stays fit by running is considered attractive by 35 percent of men—coming in second only to a woman who makes them laugh.
During puberty, body size increases for both sexes, but boys also get a burst of testosterone which results in larger, stronger muscles to control their new body; girls do not get this same rapid growth in muscle power.
The Pattern is Not New
“We found that there was no difference between elite male and female marathoners and that the age all marathoners peak, on average, is 29,” says Hunter.
Among humans, women's life span is almost 8% on average longer than men's life span. But among wild mammals, females in 60% of the studied species have, on average, 18.6% longer lifespans.
However, science suggesting women have greater muscle endurance than men could level the playing field once and for all, according to a new study recently published in the journal Applied Physiology, Nutrition, and Metabolism.
A sprinter's peak is generally reached between the ages of 23 and 30. The best sprinters (i.e. Gold Medals) generally peak at ages 22, 26, or 30. The mean AND median age is 26.
Testosterone and other hormones: The average male runner has built-in, physiological advantages over the average female runner. Higher testosterone levels are associated with more muscle mass, and muscle is what powers the human frame in movement.
There's a very broad range of time in which kids hit puberty-related growth spurts: Most girls start their sexual development between the ages of 8 and 13 (the average age is 12), and have a growth spurt between the ages of 10 and 14.
In Stage 4, puberty hits full stride. Between the ages of 10 and 15: Their breasts continue growing, and their nipples start to protrude. Pubic hair is still in a triangle, and there are now too many hairs to count.
Athletic guys tend to prefer women who enjoy working out, participate in one or more sports and who aren't always obsessed with their hair or make-up.
Dr. Postma writes, “Females often prefer to mate with high-quality males, and one aspect of quality is physical performance.” Physical prowess can trump conventional attractiveness. This goes back to the idea that women generally want partners who are physically fit to protect them.
The extra flexibility is a result of a woman's body structure and function — our hips are wider and our hormones allow our tendons to stretch for childbirth. We also have less muscle mass, allowing our bodies to move more freely.
The average age for girls to start puberty is 11, while for boys the average age is 12. But it's perfectly normal for puberty to begin at any point between the ages of 8 and 13 in girls and 9 and 14 in boys.
Researchers and physicians hypothesized about possible causes for the increase in early puberty, such as increasing rates of obesity; greater exposure to endocrine-disrupting chemicals found in food, plastics, and personal-care products; and stressful or abusive home environments.
Puberty results in very rapid somatic growth, brain development, sexual maturation, and attainment of reproductive capacity. It is accompanied by final maturation of multiple organ systems and major changes in the central nervous system and in psychosocial behavior (Patton and Viner 2007).
Puberty in boys can start as early as 9 but really hits between 11 and 14 and lasts for 3 to 4 years. Boys can continue to grow until they are 18 or even 20. The first thing your boy will notice is that his private area will be changing.