Strenuous exercise with caloric restriction: effect on luteinizing hormone secretion
Williams, N.I.; Young, J.C.; McArthur, J.W.; Bullen, B.; Skrinar, G.S.; Turnbull, B.
Medicine and Science in Sports and Exercise 27(10): 1390-1398
1995
ISSN/ISBN: 0195-9131 PMID: 8531610 Document Number: 448299
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% ovrhdot VO-2max. Each test was preceded by a 7-d treatment of controlled diet and exercise (74% ovrhdot VO-2max). 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.