Strenuous exercise with caloric restriction: effect on luteinizing hormone secretion.
To test whether strenuous exercise with and without caloric restriction alters LH secretion, and whether these changes are apparent in the immediate post-exercise period, LH pulse parameters were studied in four moderately trained eumenorrheic women over three successive menstrual cycles. Blood samples were obtained 5 h before and 5 h after 90 min of running at 74% VO2max. Each test was preceded by a 7-d treatment of controlled diet and exercise (74% VO2max). During CONTROL, subjects were eucaloric on days 1-7, and performed no exercise on days 5-7. During STTI (short-term training increase), subjects were eucaloric and completed 90 min runs on days 5-7. During DIET/STTI, subjects consumed 60% of the calories necessary to maintain weight on days 1-7, and exercised as in STTI. A significant decrease in overall (0700-1830 h) LH pulse frequency during DIET/STTI compared with CONTROL and STTI treatments was observed. No changes were found in mean serum LH levels or peak amplitude. These results suggest that high-volume training combined with caloric restriction may predispose one to exercise-induced changes in LH pulse frequency, while adequate caloric intake may prevent these changes.
Department of Health Sciences, Sargent College, Boston University, MA, USA.
N I
NI
Williams
J C
JC
Young
J W
JW
McArthur
B
B
Bullen
G S
GS
Skrinar
B
B
Turnbull
D000328:Adult; D001835:Body Weight; D004032:Diet; D004038:Diet, Reducing; D002149:Energy Intake; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D008597:Menstrual Cycle / Q000502:physiology; D015596:Nutrition Assessment; D010101:Oxygen Consumption; D012307:Risk Factors; D012420:Running / Q000502:physiology; D015431:Weight Loss
D007986:Luteinizing Hormone