STRENUOUS EXERCISE WITH CALORIC RESTRICTION - EFFECT ON LUTEINIZING-HORMONE SECRETION

To test whether strenuous exercise with and without caloric restrictio n alters LH secretion, and whether these changes are apparent in the i mmediate post-exercise period, LH pulse parameters were studied in fou r moderately trained eumenorrheic women over three successive menstrua l 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 w ere eucaloric on days 1-7, and performed no exercise on days 5-7. Duri ng STTI (short-term training increase), subjects were eucaloric and co mpleted 90 min runs on days 5-7. During DIET/STTI, subjects consumed 6 0% of the calories necessary to maintain weight on days 1-7, and exerc ised as in STTI. A significant decrease in overall(0700-1830 h) LH pul se frequency during DIET/STTI compared with CONTROL and STTI treatment s was observed. No changes were found in mean serum LH levels or peak amplitude. These results suggest that high-volume training combined wi th caloric restriction may predispose one to exercise-induced changes in LH pulse frequency, while adequate caloric intake may prevent these changes.