Effects of short-term strenuous endurance exercise upon corpus luteum function.
OBJECTIVE
The present study tested whether short-term, abruptly initiated training can cause corpus luteum dysfunction when exercise is limited to either the follicular or luteal phase of the cycle.


METHODS
Reproductive hormone excretion and menstrual characteristics were studied in sedentary women who exercised only during the follicular (N = 5) or the luteal (N = 4) phase. Six women served as controls, three of whom exercised at a low volume and three who remained sedentary. Weekly progressive increments in exercise volume continued until either ovulation (follicular group) or menses (luteal group) occurred. Physical activity and nutrient intake were closely monitored with the intent to maintain body weight.


RESULTS
No luteal phase disturbances occurred in any of the control subjects, whereas 40% of follicular and 50% of luteal exercisers experienced luteal defects. The proportion of menstrual cycles disrupted was not different between luteal and follicular exercisers (50% vs 30%, respectively) but was significantly greater than the proportion of cycles disrupted in control subjects (P < 0.05).


CONCLUSIONS
These results suggest that exposure to abrupt onset of training can alter luteal function, regardless of the menstrual cycle phase in which exercise occurs. This study also demonstrates that a relatively low volume of exercise suffices to induce mild disturbances in luteal function.
Department of Health Sciences, Sargent College, Boston University, MA, USA. niw1@psu.edu
N I
NI
Williams
B A
BA
Bullen
J W
JW
McArthur
G S
GS
Skrinar
B A
BA
Turnbull
D000328:Adult; D000704:Analysis of Variance; D019540:Area Under Curve; D001823:Body Composition; D003338:Corpus Luteum / Q000503:physiopathology*; D004032:Diet; D005260:Female; D005498:Follicular Phase / Q000502:physiology; D012739:Gonadal Steroid Hormones / Q000652:urine; D006801:Humans; D008183:Luteal Phase / Q000502:physiology; D010101:Oxygen Consumption; D010806:Physical Education and Training; D010807:Physical Endurance; D011446:Prospective Studies; D011863:Radioimmunoassay
D012739:Gonadal Steroid Hormones