The relationship between physical activity and reproductive health is one that many women think about when they’re trying to conceive, and for good reason—lifestyle factors including exercise are frequently discussed in the context of fertility. For women over 35, where fertility discussions often carry added complexity, understanding what current research actually says about exercise and fertility can help inform balanced, realistic expectations.
The short version of what research suggests is this: moderate regular physical activity appears to be beneficial for reproductive health in most women, while extremes in either direction—very high-intensity training or a highly sedentary lifestyle—may be associated with less favorable fertility outcomes in some individuals. The nuances, however, matter considerably.
This article explores the evidence on exercise and fertility for women over 35, including what types and amounts of exercise appear to be supportive, what factors might complicate the picture, and how to think about exercise as part of a broader fertility-supportive lifestyle.
What Research Shows About Exercise and Female Fertility
The relationship between exercise and fertility has been studied in various contexts, including population-based studies, studies of women undergoing IVF, and research on specific conditions such as polycystic ovary syndrome (PCOS). The findings are not entirely uniform, which reflects both the complexity of the relationship and differences in study populations and methodologies.
According to research published in several reproductive medicine journals and supported by data from the Nurses’ Health Study, moderate physical activity is associated with a lower risk of ovulatory infertility compared with inactivity. This relationship appears to hold across weight categories, suggesting that the benefit of exercise is not solely mediated through weight management.
The National Institute of Child Health and Human Development acknowledges that healthy lifestyle behaviors, including appropriate physical activity, are supportive of overall reproductive health—though specific exercise prescriptions for fertility optimization are not well-established by current evidence.
Moderate Exercise: What This Means in Practice
When research refers to “moderate” physical activity in the context of fertility, this generally means activities that raise the heart rate and breathing meaningfully but still allow for conversation—walking briskly, cycling at a comfortable pace, swimming, yoga, Pilates, and similar activities. Current physical activity guidelines for adults (which apply regardless of fertility considerations) suggest at least 150 minutes of moderate-intensity aerobic activity per week.
From a fertility perspective, research suggests that exercise in this range is generally supportive of hormonal balance, ovulatory function, insulin sensitivity, and overall metabolic health—all of which are relevant to reproductive function. For women with PCOS in particular, regular moderate exercise is associated in research with improvements in insulin resistance and hormonal parameters that may support ovulation.
Understanding the broader picture of lifestyle factors and fertility after 35 can help frame exercise as one supportive element within a wider approach.
High-Intensity Exercise: A More Complex Picture
The relationship between very high-intensity or very high-volume exercise and fertility is more complex. At the most extreme end—competitive endurance athletes, women in very intensive training programs—exercise-induced suppression of reproductive hormones (sometimes called exercise-associated menstrual dysfunction or relative energy deficiency in sport, RED-S) is well-documented. This appears to occur primarily when energy expenditure significantly exceeds intake, creating a deficit that the body compensates for by downregulating reproductive function.
For the majority of women doing regular vigorous exercise who are eating adequately, this level of reproductive suppression is unlikely. Research suggests that reproductive concerns related to high-intensity exercise tend to arise in the context of insufficient energy intake relative to output, rather than from exercise intensity alone.
Women who train extensively and notice cycle irregularities—shorter cycles, longer cycles, missed periods, or very light periods—may want to discuss this with a healthcare provider, as it may indicate that energy availability is a factor. Tracking menstrual cycle patterns relative to training load can be informative.
Exercise During Fertility Treatments
For women undergoing fertility treatments such as IVF or IUI, the question of whether to continue exercising is a common one. Research in this area is still evolving. Some studies have found associations between high-intensity exercise during IVF stimulation and lower success rates, while others have found minimal effects of moderate exercise on outcomes.
Most reproductive medicine specialists suggest reducing very high-intensity exercise during ovarian stimulation and around the time of embryo transfer, primarily due to increased ovarian size and the risk of ovarian torsion during stimulation. Moderate activity during treatment is generally considered acceptable for most women, though individual guidance from a treating specialist is essential.
Exercise and Weight: Untangling the Relationship
Body weight and adiposity are associated with fertility outcomes—both very low body weight and obesity have been linked to reproductive challenges in research. Exercise is often discussed in relation to weight management, which can make it difficult to separate the effects of exercise itself from the effects of changes in body composition.
Research suggests that the benefits of exercise on reproductive health are at least partially independent of weight effects. Women across a wide range of body sizes who engage in regular moderate activity appear to have better fertility-related outcomes than sedentary women at comparable weights. This supports the idea that physical activity has value for reproductive health beyond its role in weight management.
For women concerned about how body weight may be interacting with fertility, a conversation with a healthcare provider can help contextualize individual circumstances in a non-judgmental, evidence-informed way.
Practical Considerations for Exercise When Trying to Conceive After 35
For most women over 35 who are trying to conceive, regular moderate exercise is likely supportive of both fertility and overall wellbeing. A few practical considerations worth noting:
Starting or significantly increasing exercise before trying to conceive—rather than making dramatic changes mid-cycle—may be a more comfortable approach for many women. If you’re currently sedentary, gradually introducing walking, swimming, or yoga is a reasonable place to start. If you’re already active, maintaining your current routine with attention to energy intake and cycle patterns is generally appropriate.
Heat exposure—such as prolonged hot yoga or extended time in hot tubs—is worth being mindful of, as some research suggests elevated scrotal temperature can affect sperm in male partners, and heat exposure in early pregnancy is generally recommended to be limited. For women trying to conceive, excessive heat exposure during the luteal phase is sometimes discussed in fertility communities, though definitive evidence for this specific concern in female fertility is limited.
Frequently Asked Questions
Is it okay to keep running while trying to conceive after 35?
For most women, moderate running is considered compatible with trying to conceive. If training volume is very high, paying attention to menstrual cycle regularity and adequate caloric intake is worthwhile. Discuss your specific training routine with your healthcare provider if you have concerns.
Should I start exercising more to improve my fertility?
If you’re currently sedentary, introducing regular moderate activity is associated with benefits for overall and reproductive health. If you’re already moderately active, dramatically increasing exercise specifically for fertility purposes isn’t well-supported by current evidence. Consistency and balance are likely more important than intensity.
Can exercise affect my menstrual cycle?
Very high training volumes combined with insufficient caloric intake can disrupt hormonal patterns and affect cycle regularity. Moderate exercise typically does not disrupt the menstrual cycle and may support regularity. If you notice changes in your cycle pattern correlating with changes in your exercise routine, discuss this with a healthcare provider.
What type of exercise is best for fertility?
No single type of exercise is proven to be superior for fertility in the general population. Research suggests that moderate-intensity activities—walking, cycling, swimming, yoga—that support hormonal balance and overall health are appropriate choices for most women. Individual preferences and enjoyment matter too, as sustainable activity is most beneficial.
Key Takeaways
- Moderate regular exercise is associated with better fertility outcomes in most women and appears to support hormonal balance and ovulatory function.
- Very high-intensity or high-volume exercise combined with insufficient energy intake can disrupt reproductive hormones—cycle irregularity is worth monitoring and discussing with a provider.
- Benefits of physical activity on reproductive health appear at least partly independent of effects on body weight.
- During fertility treatments, guidance from a treating specialist about exercise is important, as recommendations may differ during stimulation phases.
- Consistency and balance are generally more important than exercise intensity for fertility support.
Medical Disclaimer
This content is for informational purposes only and does not constitute medical advice. Individual health situations vary significantly. Always consult a qualified healthcare provider before making decisions related to your health, fertility, or pregnancy.
About the Author
Emily Carter is a women’s health writer focused on fertility, pregnancy after 35, and sleep changes in midlife. She writes research-informed, non-alarmist content to help women navigate reproductive and hormonal transitions with clarity and confidence.