Abstract
To determine whether recreational levels of training (jogging) will provoke short
luteal phase menstrual cycles, a prospective study was conducted. Out of 132 women
who initiated this study 57 completed it. These individuals were within normal range
of cardiorespiratory fitness for 18-40-year-old women. After a control menstrual cycle
(#1) and two additional menstrual cycles (#2 and #3) in which light calesthenics were
performed, the subjects were then assigned to run < 10 mi/wk, 10-20 mi/wk or 20-30
mi/wk for either two menstrual cycles (#4 and #5), or four menstrual cycles (#4, #5,
#6, #7), followed by a detraining period lasting two menstrual cycles (i. e. #6 and
#7 for the 2-month running groups; #8 and #9 for the 4-month running groups). Blood
samples were obtained throughout every second menstrual cycle (i. e. cycles #1, #3,
#5, #7, #9). Samples were assayed for LH, FSH and P. Body weight and body fat (%)
were not altered by training (p > 0.05). Improvements in cardiovascular fitness did
occur (p < 0.05). No change in LH attributable to running was found in any of the
6 experimental groups (p > 0.05). In some of the groups quite large changes occurred
in FSH (p < 0.05), but there was no discernable pattern of onset of these changes
among groups. Some increments in P were found (p < 0.05) but again these were not
consistent. Finally, in none of the six groups was an altered menstrual cycle length
discernable (p > 0.05), nor was the luteal phase length altered (p > 0.05) by running.
Therefore, in gynecologically mature women recreational running of up to 30 miles/week
for 4 menstrual cycles has no deleterious effects upon their menstrual cycle.
Key words
FSH - LH - progesterone - running - menstrual cycle length - luteal phase length
