Effects of Exercise Intervention on Preventing Letrozole-Exposed Rats from Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a prevalent endocrinological disorder in reproductive-age women and is often associated with a metabolic syndrome. To investigate whether exercise intervention promotes PCOS prevention, a rat model was used. Polycystic ovary syndrome was induced by letrozole administration, and animals presented with obesity, sex hormone disorder, no ovulation, large cystic follicles, and increasing fasting insulin (FINS) and leptin levels. The intervention was set at 3 different intensities of swimming exercise: low (0.5 h/d), moderate (1 h/d), and high (2 h/d), and compared with a PCOS model group (letrozole administration without exercise intervention) and a control group. The exercise intervention in the low-intensity group did not produce changes in obesity, testosterone, progesterone (P), and follicle-stimulating hormone (FSH) levels. Moderate-intensity exercise reduced body weight, retained ovulation, and P levels were increased but remained lower than those in the control group. The FSH levels were significantly higher, and FINS and leptin levels were lower than in the model group (P < 0.05) but not in the control group. The high-intensity group demonstrated the greatest effect of PCOS prevention. Testosterone, luteinizing hormone, FINS, and leptin levels were significantly lower in the high-intensity group, and FSH and P levels were higher compared with the model group. These results suggest that high-intensity exercise intervention can effectively prevent PCOS development.