Geov

• Testosterone


  Secreted by the male testes, has a powerful anabolic effect in causing greatly increased deposition of protein everywhere in the body, especially in the muscles
• A male with normal testosterone levels

  Has muscles that grow about 40% larger than those of a comparable female without testosterone
• Estrogen


  The female sex hormone, probably also accounts for some of the difference between female and male performance, although not nearly so much as testosterone
• Estrogen


  Increases the deposition of fat in the female, especially in the breasts, hips, and subcutaneous tissue
• The average young (age 16–19 years) nonathletic female has about 34% body fat composition, in contrast to the nonathletic young male (age 16–19 years), who has about 23%
• Muscle strength


  Determined mainly by its size, with a maximal contractile force between 3 and 4 kg/cm2 of muscle cross-sectional area
• A person who has enlarged their muscles through an exercise training program will have correspondingly increased muscle strength
• Endurance


  Depends on the nutritive support for the muscle, more than anything else it depends on the amount of glycogen that has been stored in the muscle before the period of exercise
• A person who consumes a high-carbohydrate diet stores far more glycogen in muscles than does a person who consumes either a mixed diet or a high-fat diet
• Endurance is enhanced by a high-carbohydrate diet
• Heat stroke


  During endurance athletics, even under normal environmental conditions, the body temperature often rises from its normal level of 98.6°F to 102°F or 103°F (37°C to 40°C)
• Heat stroke


  With very hot and humid conditions or excess clothing, the body temperature can rise to 106°F to 108°F (41°C to 42°C), at this level the elevated temperature becomes destructive to tissue cells, especially the brain cells
• Symptoms of heat stroke

  • Extreme weakness
  • Exhaustion
  • Headache
  • Dizziness
  • Nausea
  • Profuse sweating
  • Confusion
  • Staggering gait
  • Collapse
  • Unconsciousness
• Failure to treat heat stroke immediately can lead to death
• Even though the person has stopped exercising, the temperature does not easily decrease, partly because at these high temperatures, the temperature-regulating mechanism often fails
• A second reason is that in heat stroke, the very high body temperature approximately doubles the rates of all intracellular chemical reactions, thus liberating still more heat
• Treatment of heat stroke

  1. Remove all clothing

  2. Maintain a spray of cool water on all surfaces of the body or continually sponge the body

  3. Blow air over the body with a fan
• This treatment can reduce the temperature either as rapidly or almost as rapidly as any other procedure, although some physicians prefer total immersion of the body in water containing a mush of crushed ice, if available
• As much as a 5-to 10-pound weight loss has been recorded in athletes in a period of 1 hour during endurance athletic events under hot and humid conditions
• Essentially all this weight loss results from loss of sweat
• Loss of enough sweat to decrease body weight only 3% can significantly diminish a person's performance, and a 5% to 10% rapid decrease in weight can often be serious, leading to muscle cramps, nausea, and other adverse effects
• It is essential to replace fluid as it is lost
• Anabolic steroids


  Use of male sex hormones (androgens) or other anabolic steroids to increase muscle strength undoubtedly can increase athletic performance under some conditions, especially in women and even in men
• Anabolic steroids also greatly increase the risk of cardiovascular disease because they often cause hypertension
• Anabolic steroids in men

  Lead to decreased testicular function, including both decreased formation of sperm and decreased secretion of the person's own natural testosterone, with residual effects sometimes lasting at least for many months and perhaps indefinitely
• Anabolic steroids in women

  Can cause facial hair, a bass voice, ruddy skin, and cessation of menses because she is not normally adapted to the male sex hormone
• Amphetamines and cocaine


  Have been reputed to increase athletic performance, but overuse can lead to deterioration of performance
• Experiments have failed to prove the value of these drugs except as a psychic stimulant
• Some athletes have been known to die during athletic events because of interaction between such drugs and the norepinephrine and epinephrine released by the sympathetic nervous system during exercise, one of the possible causes of death under these conditions is overexcitability of the heart, leading to ventricular fibrillation, which is lethal within seconds
• Multiple studies have shown that people who maintain appropriate body fitness, using judicious regimens of exercise and weight control, have the additional benefit of prolonged life
• Especially between the ages of 50 and 70 years, studies have shown mortality to be three times less in the most fit people than in the least fit people
• How body fitness prolongs life

  Greatly reduces cardiovascular disease through maintenance of moderately lower blood pressure, reduced blood cholesterol and low-density lipoprotein along with increased high-density lipoprotein
• How body fitness prolongs life

  Reduces the risk for several chronic metabolic disorders associated with obesity, such as insulin resistance and type 2 diabetes
• How body fitness prolongs life

  Reduces the risk for several types of cancers, including breast, prostate, and colon cancer
• Much of the beneficial effects of exercise may be related to a reduction in obesity, but exercise also reduces the risk for many chronic diseases through mechanisms that are, at least to some extent, independent of weight loss or decreased adiposity
• Musculoskeletal problems account for about 10–20% of outpatient primary care clinical visits
• Orthopedic problems


  Can be classified as atraumatic (ie, degenerative or overuse syndromes) or traumatic (ie, injury-related) as well as acute or chronic
• The history and physical examination are sufficient in most cases to establish the working diagnosis
• The mechanism of injury is usually the most helpful part of the history in determining the diagnosis
• Adhesive capsulitis ("frozen shoulder")

  Very painful shoulder triggered by minimal or no trauma, with pain out of proportion to clinical findings during the inflammatory phase, stiffness during the "freezing" phase and resolution during the "thawing" phase