Few questions come up more often in fertility clinics than this one: "Is it okay to keep exercising?" The answer is almost always yes — with important qualifications around type, intensity, timing, and whether you're in an active IVF cycle. This guide covers what the research shows at every stage of the fertility and IVF journey.
The General Case for Moderate Exercise
Physical activity has well-documented benefits for reproductive health. Moderate exercise improves insulin sensitivity (critical for ovulation, especially in PCOS), reduces chronic inflammation, supports healthy weight maintenance, and improves stress hormones — all of which support reproductive function.
The NIH physical activity guidelines recommend at least 150 minutes of moderate-intensity aerobic activity per week for adults — roughly 2.5 hours spread across the week. Research consistently shows this level of activity is not only safe for fertility but beneficial.
A landmark analysis by Chavarro and colleagues from the Nurses' Health Study found that women who engaged in vigorous physical activity had lower rates of ovulatory infertility — but the relationship was more complex at the extremes. The same researchers found that very high levels of vigorous exercise in lean women were associated with ovulatory disruption.
Summary of the moderate exercise benefit:
- Improved insulin sensitivity and glucose regulation (especially relevant for PCOS)
- Reduced BMI and adiposity (excess body fat impairs hormone signaling)
- Lower systemic inflammation (supports implantation and endometrial receptivity)
- Better mental health and stress resilience (reduces cortisol dysregulation)
- Improved sleep quality (see our sleep and fertility guide)
Excessive Exercise and Anovulation: Hypothalamic Amenorrhea
The most serious fertility risk of exercise is not from moderate activity — it is from excessive exercise combined with inadequate caloric intake. This combination triggers hypothalamic amenorrhea (HA), a condition in which the brain shuts down the reproductive axis to conserve energy.
Hypothalamic amenorrhea occurs when the hypothalamus stops releasing gonadotropin-releasing hormone (GnRH), which is the upstream trigger for the entire hormonal cascade: GnRH stimulates pituitary LH and FSH release, which drive follicle development and ovulation. Without GnRH, ovulation ceases entirely.
HA is common in:
- Elite or competitive female athletes
- Women doing >10 hours of vigorous cardio per week
- Women in caloric deficit while training heavily (regardless of BMI — lean women with low energy availability are especially vulnerable)
- Recreational runners, dancers, and cyclists who dramatically increase training volume
Warning signs of exercise-induced HA:
- Loss of period or irregular cycles (oligomenorrhea or amenorrhea)
- Difficulty sleeping despite exhaustion
- Low libido
- Frequent stress fractures or slow recovery from training
- Low energy availability (eating less than exercise output demands)
Important: HA is not just about BMI. Normal-weight and even slightly overweight women can develop HA if energy availability drops below approximately 30 kcal/kg of lean body mass per day.
The treatment for HA-related infertility is reducing exercise volume and/or increasing caloric intake — not fertility medications, which are often ineffective unless the underlying energy deficit is corrected.
BMI Effects on Fertility and How Exercise Fits In
Body weight is a major modifiable factor in fertility. Both low BMI (<18.5) and high BMI (>30) are associated with impaired fertility and worse IVF outcomes. Exercise's primary role in fertility for most people is maintaining a healthy weight and metabolic environment.
For overweight and obese women, even modest weight loss (5-10% of body weight) has been shown to restore ovulatory function and significantly improve IVF success rates. Exercise combined with caloric restriction achieves better sustained weight loss than diet alone.
For underweight women with HA, the prescription is the opposite: reduce training load, increase caloric intake, and in some cases gain weight to restore the reproductive axis.
For women in a healthy BMI range, exercise at moderate levels does not negatively affect fertility and is likely beneficial.
Taking Charge of Your Fertility Journey
Optimizing your exercise habits is one of many steps you can take to support your fertility journey.
Before or alongside clinical treatment, many people explore at-home insemination. MakeAMom makes reusable at-home insemination kits — the CryoBaby for frozen or low-volume sperm, the Impregnator for low-motility sperm, and the BabyMaker for those with sensitivities — all designed for home use without a clinic visit.
Explore home insemination kits at MakeAMom →
Male Exercise and Sperm Quality
Exercise and male fertility have a similar dose-response relationship. Moderate exercise supports testosterone production, improves insulin sensitivity, and reduces inflammation — all beneficial for sperm production.
However, excessive exercise has measurable negative effects on sperm:
Overtraining syndrome: Elite endurance athletes and extreme exercisers show suppressed testosterone levels due to hypothalamic-pituitary-gonadal axis suppression — the male equivalent of HA. Low testosterone means impaired spermatogenesis.
Body temperature: Sperm production requires temperatures 2-4°C below core body temperature, which is why the testes are located outside the body. Any prolonged elevation in scrotal temperature can temporarily impair spermatogenesis.
Anabolic steroids: This deserves special emphasis — anabolic steroids, even short-term use, cause profound and sometimes long-lasting suppression of natural testosterone production and spermatogenesis. Men who have used anabolic steroids may need 12-24 months after cessation before sperm production recovers, if it recovers at all. This should be disclosed to any fertility physician.
For male fertility, the evidence-based exercise guidelines are:
- 150 minutes moderate aerobic exercise weekly is beneficial
- Weight training (non-extreme) is beneficial for testosterone
- Avoid extreme endurance training (>10 hours/week of vigorous cardio)
- Avoid anabolic steroids entirely
- Address the cycling controversy below
The Cycling Controversy: Scrotal Heat and Sperm
Cycling — particularly long-duration cycling on narrow saddles — has been a topic of fertility concern for two reasons: scrotal heat and perineal compression.
The scrotal heat argument is intuitive: prolonged cycling, especially on a traditional narrow saddle, can compress scrotal blood flow and raise testicular temperature, temporarily impairing spermatogenesis.
The evidence is mixed but lean toward caution for men with existing sperm quality issues:
- Multiple studies show recreational cyclists (<5 hours/week) have normal sperm parameters
- Some studies of male cyclists doing >5 hours/week show reduced sperm concentration and motility
- The effect appears to be largely reversible upon reducing cycling volume
Practical guidance for men with sperm concerns:
- Consider reducing cycling to <5 hours/week while trying to conceive
- Use wider, cutout saddles that reduce perineal compression
- Cycling is not a fertility sentence — but moderation is sensible for men with borderline sperm
High-Impact vs. Low-Impact Activity: What's the Difference?
For women (not in an IVF cycle), the distinction between high-impact and low-impact exercise matters less than the overall intensity and volume:
High-impact exercise (running, jumping, HIIT): Benefits bone density and cardiovascular health. Safe at moderate volumes for fertile women. May temporarily elevate cortisol, which is fine if recovery is adequate.
Low-impact exercise (walking, swimming, yoga, cycling, rowing): Broadly safe and generally recommended as the foundation of a fertility-supportive exercise routine. Lower injury risk and lower cortisol response.
The key variable is not impact — it's intensity relative to your current fitness level and overall energy balance. A challenging yoga class and a moderate run produce similar physiological stress.
Exercise During the Two-Week Wait (TWW)
The two-week wait — the period between ovulation or embryo transfer and the pregnancy test — is one of the most anxiety-provoking periods in a fertility journey. Countless online forums debate whether exercise in the TWW affects implantation.
The honest evidence-based answer: there is no high-quality research showing that moderate exercise in the TWW impairs natural conception or IVF implantation.
General guidance for the TWW:
- Moderate exercise (walking, gentle yoga, swimming) is safe and psychologically helpful
- Avoid high-intensity exercise that causes significant physical stress (marathons, intense HIIT sessions)
- Avoid exercises that significantly raise core body temperature (hot yoga, hot tubs, saunas)
- Use common sense: if something feels uncomfortable or painful, stop
The psychological benefit of maintaining gentle exercise during the TWW — reducing anxiety, improving sleep, maintaining routine — is likely worth more than the marginal physical risk of a brisk walk.
What to Do During an IVF Cycle Specifically
IVF cycles have unique physical considerations that require modifying your exercise routine. Here are the evidence-based guidelines:
During Ovarian Stimulation (Days 1-Trigger)
As your ovaries develop multiple follicles, they can grow to several times their normal size. This creates a real risk of ovarian torsion — a medical emergency where the ovary twists on its blood supply.
Avoid during stimulation:
- High-impact exercise (running, jumping, HIIT, aerobics classes)
- Exercises with sudden direction changes (racquet sports, soccer, basketball)
- Core-heavy exercises that increase intra-abdominal pressure
- Heavy weightlifting
Safe during stimulation:
- Walking (at any pace)
- Gentle yoga or stretching
- Swimming (low intensity)
- Light cycling on a stationary bike
- Pilates (gentle, not reformer with high resistance)
After Egg Retrieval
The risk of ovarian torsion is highest after retrieval, when the ovaries are maximally enlarged and at risk. Ovarian hyperstimulation syndrome (OHSS) — which causes further ovarian enlargement and fluid accumulation — is also a risk.
After retrieval: Complete rest for 24-48 hours. Then return only to very gentle walking. No vigorous exercise until the ovaries have reduced in size (confirmed by ultrasound or until bleeding stops). Your clinic will give specific guidance — follow it.
During the Luteal Phase and After Transfer
After transfer: There is no evidence that bed rest after embryo transfer improves implantation rates. ASRM guidelines explicitly state that routine bed rest is not recommended. However, vigorous exercise (particularly anything that dramatically elevates heart rate or raises core temperature) is generally advised against for 5-7 days after transfer.
Safe after transfer:
- Walking
- Gentle yoga (avoid inversions if they feel uncomfortable)
- Gentle stretching
- Swimming after the 5-day mark (avoid pools in the first few days due to infection risk)
Exercise as Stress Reduction During Fertility Treatment
One underappreciated benefit of exercise during fertility treatment is its role in psychological wellbeing. The emotional toll of IVF — the injections, the waiting, the uncertainty — is significant. Moderate exercise is one of the most effective evidence-based interventions for anxiety and depression.
The key is choosing exercise types that feel restorative rather than depleting. For many people, vigorous exercise that previously served as a stress outlet may need to be temporarily replaced with gentler modalities — walks, yoga, swimming — that provide the mental health benefit without the physical demands that aren't appropriate during stimulation.
Summary: Exercise Guidelines by Stage
| Stage | Recommended | Modify/Limit | Avoid |
|---|---|---|---|
| Trying to conceive (natural) | 150 min/week moderate activity | Extreme endurance training | Anabolic steroids, HA-risk levels of exercise |
| IVF stimulation | Walking, gentle yoga, light swimming | Nothing vigorous | Running, HIIT, weights, high-impact |
| After retrieval (48h) | Rest | -- | Everything except gentle movement |
| Luteal/TWW | Walking, gentle yoga | Vigorous cardio | Core-temp-raising activities (hot yoga, saunas) |
| After transfer | Walking, swimming (after day 5) | Any vigorous activity | HIIT, heavy weights, inversions |
For more on how body weight specifically relates to IVF success rates, see our BMI and IVF success rates guide.
Frequently Asked Questions
Q: Is it safe to exercise during IVF? A: Generally yes, but intensity and timing matter. Low-impact exercise (walking, light cycling, gentle yoga) is considered safe throughout most of the cycle. During ovarian stimulation, when the ovaries enlarge, avoid high-impact activities that could increase the risk of ovarian torsion. After egg retrieval, rest for 48 hours, then return to gentle movement. After embryo transfer, continue light walking but avoid vigorous cardio, heavy lifting, and heat-generating activities through the two-week wait.
Q: Can too much exercise reduce fertility? A: Yes, in extremes. Very high training loads — particularly in women with low body fat — can suppress the hypothalamic-pituitary-ovarian (HPO) axis, leading to irregular or absent ovulation (functional hypothalamic amenorrhea). Elite athletes and those in intense endurance training are most at risk. If you exercise heavily and have irregular cycles, discuss this with your reproductive endocrinologist before beginning fertility treatment.
Q: What type of exercise is best when trying to conceive naturally? A: Moderate aerobic exercise (150 minutes per week of brisk walking, swimming, or cycling) combined with resistance training is associated with the best reproductive outcomes in population studies. This level improves insulin sensitivity, regulates weight, and supports hormonal balance without the suppressive effects of extreme training loads.
Q: Does exercise improve IVF outcomes? A: The evidence is mixed and mainly comes from small studies. Moderate pre-cycle exercise may improve embryo quality by improving mitochondrial function in oocytes. However, no randomized trial has demonstrated that starting an exercise program during IVF treatment improves live birth rates. The safest current interpretation: maintain your existing moderate exercise routine, but avoid starting intense new training immediately before or during an IVF cycle.
Q: Should I do yoga during IVF? A: Restorative yoga and gentle stretching are appropriate throughout most of the IVF cycle. Avoid hot yoga (raises core temperature), Bikram yoga, vigorous vinyasa, and inversions. During stimulation and after retrieval, poses that compress or twist the abdomen should be avoided. After day 5 post-transfer, gentle walking and light yoga can resume.
