My Recommendations on Exercise and Fertility

As a double board-certified reproductive endocrinologist and OB-GYN, I love answering common questions about fertility. One of the most common queries from patients and followers is about lifestyle: How much should I exercise when I’m trying to conceive? 

(In fact, this other post about fitness and fertility is one of the most popular blogs on my site.) 

In general, exercise is good for you. Moving your body is wonderful. Exercise decreases the risk of high blood pressure, insulin resistance, and diabetes. It helps your mental health and overall well-being. Yet, some data suggests that too much exercise might negatively impact fertility.

If you’re confused about this topic, you’re not alone. It seems like wherever you look, someone or some resource has a different opinion on fitness and fertility. In this blog post, I’m going to review evidence to answer what you should (and shouldn't do) while you're trying to conceive, grouped by common sub-questions related to the topic.

Are there fertility benefits to not exercising?

Everyone is different when it comes to fertility and exercise. There’s no one-size-fits-all answer. You might have received advice to hold off on exercise entirely. While your unique needs need to be discussed with your doctor, there is an interesting study I want to share.

This study explored the benefits of movement regardless of weight. It was discovered that women who fit into a “normal” weight on a medical chart have lower fertility rates if they’re sedentary. Food for thought.

What body weight is best for fertility? 

When people are trying to conceive, it’s common to focus on exercise as a tool for weight loss. Obesity has been associated with irregular menstrual cycles, lower success with fertility treatment, and decreased fertility rates. 

However, it’s hard to say that a certain number on a scale is going to impact someone’s fertility. There are some people who are fertile at a weight considered “overweight” or “obese by definition. It’s not black and white. As archaic of measurement as it is, there’s no BMI (body mass index) that’s going to instantly make someone more fertile because we’re all fertile at different weights. Every person’s body is different, and you generally can’t equate a number on a scale with health or reproduction. 

There is some data that suggests a high body weight can impact overall fertility. While this article is from 2015, it explores how high insulin levels can impact ovulation and how high levels of estrogen stored in fat cells can impact reproductive wellbeing. 

How much is too much exercise? 

One study in Norway looked at the self-reported lifestyles of over 4,000 women. The data showed that moving your body up to three hours per week was associated with regular menstrual cycles and higher fertility.

But, on the flip side, the data indicated that too much exercise (read: exercising to the point of exhaustion) causes stress on your body that can lower fertility rates. 

Another study showed that high-level athletes who engaged in highly active and strenuous exercise took a long time to conceive. There was an impact on overall fertility. 

The takeaway? Balance is key. 

Are there exercise recommendations I can follow? 

We know that moving your body is good. We also know that being overweight can be associated with lower fertility rates. We’ve also seen that strenuous exercise in high-level athletes can create a longer time conceiving. 

If you’re looking for a sweet spot for recommendations, you might want to look at this meta-analysis, where multiple studies were pulled together to arrive at a recommendation. Regular exercise more days than not (but not to the point of exhaustion) seems to be the universal recommendation.

Can I exercise intensely if I have regular menstrual cycles? 

Some mentors in my training told me that as long as women were having menstrual cycles, they are not exercising too much. The menstrual cycle is a litmus test. In my eyes, it’s a vital sign of reproductive health because there’s so much internal communication within your body to even have a menstrual cycle once a month. When a menstrual cycle is regular, it can be an indication that a lot of factors are working. 

However, a regular menstrual cycle isn’t the end-all-be-all of reproductive health. There are people with regular menstrual cycles who take longer to conceive. With this in consideration, my recommendation is to modify exercise for your unique situation. 

Can I exercise intensely if I keep my heart rate below a certain number? 

Some people are told to exercise all they want but keep their heart rate under 140bpm. That might be okay for a lot of people, but I don’t think this can be a universal rule for everyone. 

The fitter you are, the more your heart can perform at a lower heart rate. Some incredible athletes might have a heart rate that never goes over 100bpm. 

While heart rate can be an indicator of intensity, it’s hard to make a specific number fit a mold when it comes to exercise and fertility. Focus on movement and overall health—more low impact than HIIT or other exercises with intense bursts of energy use.

My recommendations about exercising for fertility. 

While everyone is different, here is what I tell my patients:

Move your body. Don’t stop exercising, but think about modifications. 

When you push your body to exhaustion (where you’re sweating profusely and unable to talk from panting), you’re getting an endorphin rush, but you’re also pushing out cortisol. As a stress hormone, cortisol can push your body into fight or flight mode. The more strenuous exercise you put on your body, the less your body will focus on reproduction. 

If you follow me on Instagram or TikTok, you know I love my Peloton. It got me through some of the most stressful times during quarantine because I couldn't do other forms of exercise. I often tell my patients to do low-impact rides on the Peloton. Aim for instructors like Cody or Robin, not Alex or Kendall. Try low-impact and recovery rides, not tabata rides.

Yoga is also wonderful, but there are some really intense yoga classes out there, like ones with high heat. You might do some low-impact yoga and modify to cut out inversions or anything too strenuous. 

Can you please recap? 

To exercise or not to exercise? My answer is different for every person. Talk to your doctor about what’s right for you. You don’t need to completely cut out exercise, but you might need to modify. 

I hope this was helpful. For any other questions, please comment on my YouTube video.