12 weeks of combined exercise is better than aerobic exercise for increasing growth hormone in middle-aged women.
BACKGROUND
The purpose of this study was to examine the effects of combined exercise training on growth hormone (GH), insulin-like growth factor-1 (IGF-1), and metabolic-syndrome factors and determine whether the changes in GH and/or IGF-1 induced by exercise correlate to the metabolic-syndrome factors in healthy middle-aged women (50-65 years of age).


METHODS
The participants were randomly assigned into an aerobic-exercise training (walking + aerobics) group (AEG; n = 7), a combined-exercise training (walking + resistance training) group (CEG; n = 8), or a control group (CG; n = 7). Exercise sessions were performed 3 times per wk for 12 wk. The aerobic-exercise training consisted of walking and aerobics at 60-80% of heart-rate reserve, and the combined-exercise training consisted of walking and resistance exercise at 50-70% of 1-repetition maximum.


RESULTS
GH, percentage body fat, fasting glucose, systolic blood pressure, and waist circumference were significantly improved in CEG (p < .05). However, GH induced by exercise training showed no correlation with metabolic-syndrome factors. IGF-1 was not significantly increased in either AEG or CEG compared with CG.


CONCLUSIONS
These results indicate that the combined-exercise training produced more enhancement of GH, body composition, and metabolic-syndrome factors than did aerobic-exercise training.
Seo
Dong-Il
DI
Institute of Sports Science, Seoul National University, Seoul, Korea.
Jun
Tae-Won
TW
Park
Kae-Soon
KS
Chang
Hyukki
H
So
Wi-Young
WY
Song
Wook
W
D000368:Aged; D000375:Aging / Q000097:blood / Q000502:physiology; D001823:Body Composition; D005260:Female; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D024821:Metabolic Syndrome / Q000097:blood / Q000517:prevention & control*; D008875:Middle Aged; D017698:Postmenopause; D055070:Resistance Training; D012307:Risk Factors; D016138:Walking / Q000502:physiology*
D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I