EXERCISE AND FERTILITY: How much is too much?
I get this question at least weekly in clinic and since it’s a pretty hot topic and we haven’t blogged about it in quite a few years, I thought I would shed some light and include some more up to date information and studies. The first thing we need to do is separate the facts for men and women.
Exercise and Male Fertiltiy
MEN: Exercise has been shown to greatly improve male fertility. Studies show that exercise can improve testosterone levels and semen quality for men. Another study states, “Physically active subjects seem to have a more anabolic hormonal environment and a healthier semen production.” Men who were engaging in exercise for one hour per day had a 48% higher concentration of sperm than men who were engaging in less than one hour per week. So far, there hasn’t been any studies to show that overexercising is harmful for male fertility. However cycling is typically discouraged due to its effect on raising testicular temperature and negatively affecting spermatogenesis. Men who rode a bicycle for more than an hour and a half each week had 34 percent lower sperm concentrations than men who did not bike.
Obesity in men (with a BMI over 30) has been shown to raise scrotal temperature negatively impacting spermatogenesis, lower testosterone levels, and increase sperm DNA fragmentation. Daily exercise is crucial in these cases to bring BMI to healthier levels for fertility (18.5-25). Increase in BMI over 25 has been shown to correlate with poorer level of semen quality.
Exercise and Female Fertility
WOMEN: For women it gets a little bit more complicated. A study published in Fertility and Sterility showed that vigorous exercise for 3-4 hours per week has been shown to have a negative correlation in fertility for women. 22% lower chances of pregnancy for women who are overweight (BMI 25 and above), and 30% lower chances of pregnancy for women of healthy weight (BMI 25 and lower). Vigorous exercise for 30-60 minutes per day carries an increased risk of anovulation and disrupted HPA (hypothalamus-pituitary-adrenal) axis and resulting hormone imbalance.
What counts as vigorous exercise then? I typically tell patients that if they are not able to somewhat hold a conversation during exercise, or feel depleted or exhausted after exercise as opposed to energized, then that counts as too vigorous. This may mean that bootcamp or intense Soul Cycle class may not be the best. I encourage my patients to practice yoga, go for light jogs, walks, practice strength training, gardening, swimming, and other less intensive exercises when trying to conceive.
Exercise and IVF / IUI Outcomes
This is especially important when you are going through assisted reproductive procedures like IUI and IVF. Data shows that intense cardio exercises like running, cycling, and stair climbing were detrimental to IVF outcomes.
This does not mean to be afraid of exercise when you are trying to conceive! Studies show that regular exercise IS important for healthy fertility as it promotes hormone balance and detoxification, reduces stress levels, and lowers oxidative stress/inflammation. An active lifestyle in the preceding year favorably impacts IVF outcomes.A handful of studies have shown that exercise for overweight/obese women suffering from PCOS or anovulatory infertility can lead to resumption of ovulation and more regular cycles (and thus improved fertility) with exercise regardless of diet.
If you have any more questions about fertility and want to talk about a treatment plan to increase your chances of conception, give Acubalance a call at 604-678-8600 to schedule a complimentary 15 minute phone consultation with one of our experienced practitioners.