title: Effects of sustained moderate exercise on cholesterol, growth hormone and cortisol blood levels in three age groups of women.
abstract: OBJECTIVE
  The objective of this study was to determine the effects of sustained moderate exercise on cholesterol, cortisol, and growth hormone blood levels in women of three age groups.
  
  
  METHODS
  A four-week exercise program followed by one week of no exercise. The exercise program consisted of 20 minutes of moderate exercise three times a week for four weeks. Venipuncture was performed weekly.
  
  
  METHODS
  The exercise and venipunctures took place in a large room with phone access and ample space to move.
  
  
  METHODS
  A convenience sample of five pre-menopausal (20 to 30 years), 11 peri-menopausal (40 to 50 years), and 9 post-menopausal (60 to 85 years) healthy women participated in the study.
  
  
  METHODS
  Paired samples t-tests were used to compare changes in cholesterol, growth hormone, and cortisol of individuals from week zero (pre-exercise) to week four (last exercise) to week five (one week post exercise).
  
  
  RESULTS
  There were no significant differences between pre-exercise and post-exercise growth hormone levels for post-menopausal women, however, there appeared to be a trend in growth hormone increase over time. There were no significant differences between pre-exercise and post-exercise cholesterol levels for any of the three age groups of women but trends for decreased cholesterol levels were observed in the peri-menopausal and post-menopausal women. Cortisol levels did not appreciably change in response to regular exercise.
  
  
  CONCLUSIONS
  Although this study did not generate definitive data there were trends toward the proposed hypotheses. Future studies may include increasing the number of participants, implementing a longer test period to validate exercise-induced increases in growth hormone and decreases in cholesterol levels, and employing insulin-like growth factor (IGF-1) as an indicator of growth hormone levels.
authors.affiliation: Clinical Laboratory Sciences Program, School of Allied Health Professions, Northern Illinois University, DeKalb IL 60115-2854, USA. dcearlock@niu.edu
authors.forename: D M
authors.initials: DM
authors.lastname: Cearlock
authors.forename: N A
authors.initials: NA
authors.lastname: Nuzzo
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002784:Cholesterol / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005260:Female; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008875:Middle Aged
chemical_list: D019382:Human Growth Hormone; D002784:Cholesterol; D006854:Hydrocortisone