The Relationship Between Exercise & Fertility
With other lifestyle factors such as smoking, diet and alcohol consumption being contributors to infertility, the relationship with exercise is not as well defined.
Engaging in regular physical activity can positively influence fertility in women but the type and intensity of exercise for the specific person should be considered and individualized. Studies have shown that participating in moderate-intensity activities for approximately 30 minutes per day has been associated with improving fertility. This relation is most likely due to maintaining a healthy body weight and hormonal balance, which are both essential for ovulation and fertility.
On the other hand, a study compared runners (running around 32km/week) with sedentary women and examined their menstrual cycle with hormonal markers. The study showed that 58% o the runners had menstrual cycle abnormalities, including anovulation and insufficiency luteal phase vs. only 9% of the sedentary women. Instead of tracking the specific kilometres the runners were running, they examined the energy balance. Specifically, cycles that were categorized as anovulatory were associated with a lower energy balance than those with other types of cycles.
An instance where exercise has been shown to be advantageous is in women who are diagnosed with polycystic ovarian syndrome (PCOS). Studies indicate that as little as 30 minutes of vigorous exercise three times per week can significantly enhance conception chances among overweight women with PCOS. This improvement is attributed to better insulin sensitivity and hormonal regulation resulting from consistent exercise.
Another study demonstrated that women who are more physically active, particularly during pregnancy, experience a shorter active labor period. Additionally, women with increased physical activity levels were less likely to require oxytocin or an epidural during labor.
In summary, regular moderate exercise, such as 30 minutes per day, can improve fertility by maintaining a healthy weight and hormonal balance. However, excessive exercise, like long-distance running, may cause menstrual irregularities and anovulation due to energy imbalance. The type and intensity of exercise should be tailored to individual needs for optimal fertility.
References:
Mussawar M, Balsom AA, Totosy de Zepetnek JO, Gordon JL. The effect of physical activity on fertility: a mini-review. F S Rep. 2023 Apr 14;4(2):150-158. doi: 10.1016/j.xfre.2023.04.005. PMID: 37398617; PMCID: PMC10310950.
Watkins VY, O'Donnell CM, Perez M, Zhao P, England S, Carter EB, Kelly JC, Frolova A, Raghuraman N. The impact of physical activity during pregnancy on labor and delivery. Am J Obstet Gynecol. 2021 Oct;225(4):437.e1-437.e8. doi: 10.1016/j.ajog.2021.05.036. Epub 2021 Jun 1. PMID: 34081895; PMCID: PMC10564562.
Savla R, Mullerpatan R, Agarwal B, Kuttan V, Kumar S. Influence of Physical Activity Including Squat Exposure on Trunk Muscle Strength and Labour Outcome in Pregnant Women. Int J Exerc Sci. 2024 Apr 1;17(1):504-516. doi: 10.70252/VGAK1504. PMID: 38665166; PMCID: PMC11042859.