Sports Medicine: Just the Facts

CHAPTER 98 • THE FEMALE ATHLETE 573

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98 THE FEMALE ATHLETE

Rochelle M Nolte, MD

Catherine M Fieseler, MD

INTRODUCTION

• In 1971, there were fewer than 300,000 girls partici-
  pating in high school athletics, compared to 3.7 mil-
  lion boys. Title IX was passed in 1972, mandating
  nondiscrimination in all extracurricular activities
  and varsity athletics that received federal funding.

In 2000, there were 2.7 million girls involved in high

school sports compared to 3.8 million boys (Slater

and Stone, 2002).

•Benefits of exercise for girls and women include

decreased cholesterol levels and heart disease,

decreased incidence of breast, endometrial, gall

bladder, and colon cancer, improved self-image,

body-image, and sense of well-being, increased con-

fidence and improved social skills and decreased

school dropout rates, and decreased rate of unwanted

or unplanned pregnancy (Lopiano and Modern,

2000).

ANATOMY AND PHYSIOLOGY

• Prior to puberty, there are no gender differences in
  testosterone and estradiol concentrations (Strickland
  and Metzl, 2002).


• Girls start puberty an average of 2 years earlier than
  boys.


• Peak height velocity for girls ranges from 10.5 to 13
  years and for boys, 12.5 to 15 years (Sanborn and
  Jankowski, 1994).


• Menarche occurs approximately 1 year after peak
  height velocity.


• Adult height is reached by age 17 to 19 years for girls
  and by age 20 to 22 for boys.
  •Skeletal maturity is completed by age 18 to 19 for
  girls and age 21 to 22 for boys.
  
  
  1. Overall, osseous development correlates better
     with sexual maturation than does age, height, or
     weight (Sanborn and Jankowski, 1994).
     •VO2maxaverages around 50 mL/kg/min in prepubes-
     cent children, and changes little in boys throughout
     puberty, but decreases in girls with puberty secondary
     to a change in body composition and a decreased per-
     centage of lean body mass.
  
  
  
  


• After puberty, metabolically active muscle averages
  40–45% of total body weight in boys, but only
  35–38% in girls (Lillegard, 2001).
  •Women on average are shorter, weigh less, and have
  shorter limbs and smaller articular surfaces, narrower
  shoulders and smaller thoraces, and a wider pelvis in
  relation to their waist and shoulders than men. Women
  have less muscle mass per total body weight than
  equally trained and conditioned men. The average
  young adult female has approximately 20 to 27%
  body fat, while the average young adult male has 12
  to 18% body fat (Sanborn and Jankowski, 1994;
  Fieseler, 2001).
  •Women have a smaller heart size, smaller stroke
  volume, and higher heart rate for a given submaximal
  cardiac output (Mittleman and Zacher, 2000).