Effect of a Three-Month Exercise Regime on Androgens and Sex Hormone-binding Globulin of Premenopausal Students of Nnamdi Azikiwe University, Nnewi, Nigeria

Abstract

Background: There is traditional conviction that if premenopausal women engage in prolonged physical exercise, they are likely to become masculinized and develop infertility. Androgens, although traditionally thought to be male sex steroids, play important roles in female reproduction. That both excess and deficiency of androgens can cause female infertility is poorly recognized. This study assessed the effect of a three- month moderate-to-vigorous intensity exercise on androgens and sex hormone binding globulin (SHBG) in premenopausal female students of Nnamdi Azikiwe University (NAU), Nnewi. Study Design: This was a longitudinal comparative study. Methods: This study involved 80 participants aged between 19 and 25 years, randomly selected and assigned to exercise group and control group. The exercise group comprised 40 participants who engaged in moderate –to-vigorous intensity exercise using elliptical bicycle for 30 minutes, five days a week for 3 months.  Only 30 individuals completed the exercise. The control group comprised of 40 individuals that did not participate in the exercise; only 30 individuals also completed the study. Two mililitres of blood was collected from each participant at baseline, 1 month, 2 months, and 3 months.  The SHBG, total testosterone and free testosterone were determined using ELISA method. The independent Student’s t- test was used to assess statistical significance, with p set at p<0.05, while paired t-test was used to assess the mean differences.   Results: Serum free testosterone was significantly lower (1.115±0.177pg/ml) after 3 months of exercise compared with the control (1.463±0.175pg/ml). Total testosterone on the other hand did not differ from both control and baseline values after 3 months exercise. The level of SHBG was significantly higher (64.76±3.34 nmol/l) after 3 months of exercise compared to baseline (62.96 ± 3.22 nmol/l) and control (62.80±3.25 nmol/l). Conclusion:  Moderate –to-vigorous intensity exercise for 3 months may reduce the bio-available androgens in premenopausal women. Further studies are needed to confirm these preliminary data.