Aims: The effect of menstrual cycle and its factors on the health is a significant part in the women studies. In each phases of menstrual cycle, different physiological and hormonal changes occur in females’ body that all affect their performance capacity. This study was undertaken aiming at investigating the effect of menstrual cycle on growth hormone and aerobic power in non-athletic girls.

Methods: This causative cross-sectional post hoc was conducted clinically on the population of 15 to 17 year old girls in Ghom, Iran, who were studying in high schools of the given city in 2010-11 and 15 students were selected using purposive cluster sampling. Subjects referred to the specialized laboratory in three different menstrual cycles including menstruation or menstrual bleeding phase (the third day), follicular phase (the twelfth day) and luteal phase (the twentieth first day) for measurement of growth hormone. Data was analyzed using SPSS 17 and LSD persuasive test.

Results: The mean of growth hormone level in different phases of menstruation, follicular and luteal had a significant difference (p<0.001). However, the mean of aerobic power revealed no significant difference (p>0.05).

Conclusion: In spite of the lack of effect on the aerobic power, different phases of menstrual cycle affect the level of growth hormone in the non-athletic girls of 15-17 years of age however, it doesn’t impose any limitation on aerobic exercise in practice.