Sports Medicine: Just the Facts

CHAPTER 32 • ENDOCRINE CONSIDERATIONS 185

3. There was no significant difference between men
   and women.


4. Cortisol levels were significantly reduced at rest
   (8 weeks).

• Cortisol levels acutely increase with heavy resistance
  protocols in men and women (Hakkinen and
  Pakarinen, 1995; Kraemer et al, 1990; 1998).


• Cortisol levels increase in women immediately after
  resistance training.


• Higher levels were seen with a multiple set protocol
  when compared to a single set protocol (Consitt et al,
  2002).


• Chronic exercise: Increased levels of cortisol have
  been reported in overtraining (Consitt et al, 2002).


• Elite endurance female athletes had significantly
  greater cortisol levels than their sedentary counter-
  parts.


• Chronic resistance exercise results in decreased rest-
  ing levels of cortisol (anabolic effect).

1. Kraemer et al (1998) found decreased values after
   8 weeks of heavy resistance training.
   2.Marx et al (1998) showed a decline in resting corti-
   sol in female athletes who completed a high-volume
   protocol versus low-volume protocol.

B. Aldosterone

• Endurance exercise:Aldosterone increases to help
  decrease the sweat loss of sodium chloride following
  acclimatization to a hot environment (Brooks, Fahey,
  and White, 1995).
  
  
  • Prolonged exercise (90 min at 60% VO2max) signifi-
    cantly increased aldosterone levels in untrained men.
  
  
  
  

ADRENALMEDULLAHORMONES ANDEXERCISE

Epinephrine/Norepinephrine (Catecholamines)

• Endurance exercise:Ninety minutes at 60% VO2max
  significantly increased catecholamine levels in previ-
  ously untrained men (Roy et al, 2001).


• Intensity less than 50% VO2max had no effect on cate-
  cholamine levels; intensity above 50% VO2max
  increased catecholamine release.


• Norepinephrine increased more than epinephrine
  (Brooks, Fahey, and White, 1995).


• Untrained men exercising for 60 min at 50% VO2max
  increased catecholamine levels during the exercise
  session (Marion-Latard et al, 2003).
  •A significant increase in epinephrine/norepinephrine
  resulted with 2 bouts of exercise (75 min, 75% VO2max)
  
  
  1. Bouts were followed by a 3-h rest period or 6 h of
     rest.
  
  
  2. Increased levels were more profound than after 2
     bouts of exercise with 6 h of rest.
  
  
  3. The 2nd bout exhibited greater increase in cate-
     cholamine levels (Ronsen et al, 2002).
  
  
  
  


• Catecholamine levels increased two- to fourfold with
  moderate exercise (<80% VO2max)
  
  
  1. Intense exercise (>80% VO 2 ) resulted in a four-
     teen- to eighteenfold increase of epinephrine/nor-
     epinephrine.
  
  
  
  

TABLE 32-3 Adrenal Cortex Hormones

GLAND HORMONE CONTROL ACTION ENDURANCE RESISTANCE CHRONIC

Adrenal Cortisol Stress, diurnal rhythm, Glucose sparing; Increased; increased Increased Decreased with
cortex Glucocorticoid hypothalamic promotes use of intensity and/or acutely resistance training;
CRH, ACTH fatty acids and protein; increased duration; decreases protein
insulin antagonist; glucose sparing degradation leading
anti-inflammatory to fiber hypertrophy;
effects volume related
Aldosterone Angiotensin, Balance Na+and K+ Increase; intensity Unknown Unknown
Mineralcorticoid renin, potassium levels; kidney fluid and duration
levels; ACTH maintenance dependent; because
(stress at the of constriction of
hypothalamus) blood flow to kidney

TABLE 32-4 Adrenal Medulla Hormones

GLAND HORMONE CONTROL ACTION ENDURANCE RESISTANCE CHRONIC

Adrenal Epinephrine Hypothalamic Augment SNS; glycogen Increases;intensity and Intensity dependent;
medulla Norepinephrine sympathetic catabolism; FA release; duration dependent; response decreased
nerves increases cardiac output; blood flow distribution, during submaximal
flight or fight response cardiac contractility, exercise; with
glycogenolysis maximal exercise
and lipolysis response >or =to
untrained