The Science Behind Fertility Exercise | The Fertility Class

Does pelvic blood flow affect egg quality and IVF outcomes?

Ovarian Blood Flow and Egg Quality 

Research consistently shows that ovarian blood flow is directly associated with oocyte quality and ovarian reserve. Reduced circulation to the ovaries has been linked to diminished follicular function and lower-quality eggs.

• Lower ovarian blood flow is associated with reduced egg quality and function: 

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC9929747
2. https://pmc.ncbi.nlm.nih.gov/articles/PMC5819322

Ovarian Blood Flow and Follicle Development 

Adequate ovarian circulation plays a critical role in follicular development and ovulation. In ART populations, poor ovarian perfusion correlates with lower follicle maturation rates and worse clinical outcomes.

• Decreased ovarian blood flow has been associated with poorer follicle maturation and ART outcomes: 

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC3454957

The Fertility Class includes movement sequences that activate the lower abdominal and pelvic muscles. These sequences are designed to support circulation in the pelvic region, including to the ovaries.

How does uterine circulation affect implantation rates?

Uterine Blood Flow and Implantation 

Uterine blood flow is a recognized factor in implantation success. Adequate perfusion of the uterine wall is necessary to support the early stages of embryo attachment and pregnancy development. Reduced uterine blood flow has been associated with lower implantation rates across both natural conception and assisted reproduction.

• Reduced uterine blood flow has been associated with lower implantation rates and pregnancy outcomes: https://pmc.ncbi.nlm.nih.gov/articles/PMC10133733

Uterine Artery Pulsatility Index

Uterine artery blood flow resistance, measured by pulsatility index (PI), is a standard clinical marker in reproductive medicine. A higher PI indicates greater vascular resistance and reduced delivery of blood to the uterus. Elevated PI has been associated with lower clinical pregnancy rates in IVF.

• A higher pulsatility index has been linked to lower fertility and reduced ART success rates: 

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC4696374

The movement sequences in The Fertility Class engage the pelvic and lower abdominal musculature. By activating these muscle groups, the sequences are designed to support circulation to the uterine region.

What does the research show about endometrial blood flow and pregnancy rates?

Endometrial Blood Flow and Implantation 

The uterine lining must be adequately vascularized at the time of implantation. Endometrial and subendometrial blood flow are measurable clinical indicators of uterine receptivity. Research consistently shows that higher endometrial perfusion correlates with better reproductive outcomes.

• Women with detectable blood flow in both the endometrium and subendometrial region had significantly higher pregnancy rates: https://pubmed.ncbi.nlm.nih.gov/12137858/
• Increased endometrial blood flow has been associated with improved ART outcomes and higher pregnancy rates: https://pmc.ncbi.nlm.nih.gov/articles/PMC11534959

By activating the deep abdominal and pelvic muscles, The Fertility Class™ supports healthy pelvic circulation, including to the uterine lining.

Does exercise improve fertility outcomes?

A growing body of research links regular, moderate movement to improved menstrual regularity, better ovulatory function, and improved outcomes in assisted reproduction.

• Moderate physical activity has been associated with improved menstrual cycle regularity, increased ovulation rates, and better ART outcomes: 

https://pmc.ncbi.nlm.nih.gov/articles/PMC5741916

• A systematic review and meta-analysis found that maternal physical activity before IVF/ICSI cycles was associated with higher clinical pregnancy and live birth rates: 

https://pmc.ncbi.nlm.nih.gov/articles/PMC5803901

Does high-intensity exercise harm fertility?

The evidence is consistent: the reproductive benefit of exercise applies to moderate-intensity movement, not vigorous or high-intensity training. Intensity matters.

• Vigorous, high-frequency physical activity has been associated with increased subfertility and delayed time to conception: https://pmc.ncbi.nlm.nih.gov/articles/PMC7614776
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The Fertility Class is built around targeted, low-impact movement sequences precisely because of this distinction. It is not a cardio or general fitness program, it is a structured sequence of specific pelvic and abdominal movements, designed to achieve circulatory and hormonal benefits without the intensity that research associates with reproductive suppression.

How does stress affect reproductive hormones, and what can help?

The nervous system and reproductive system are directly linked. Chronic stress disrupts the hypothalamic-pituitary-ovarian axis, the hormonal pathway that governs ovulation and menstrual function. This is the biological mechanism behind stress-related cycle irregularity and conditions like hypothalamic amenorrhea.

• Chronic activation of the stress response has been shown to suppress GnRH secretion, the hormone that initiates the ovulatory cascade: https://pmc.ncbi.nlm.nih.gov/articles/PMC6129417
• Elevated stress hormones inhibit gonadotropin-releasing hormone release from the hypothalamus, suppressing reproductive hormone output:                                 https://pmc.ncbi.nlm.nih.gov/articles/PMC4166402

The Fertility Class incorporates breathwork and nervous system-regulating elements alongside movement, recognizing that hormonal health depends on both circulation and the reduction of chronic physiological stress.

Three studies have evaluated the Aviva Method directly - the structured movement practice The Fertility Class classes are rooted in. Below is an accurate summary of each, including their actual findings and limitations.

Does the Aviva Method reduce menstrual pain?

A 2024 clinical study tested a twice-weekly, 30-minute Aviva exercise intervention against a control group in 78 women with primary dysmenorrhea.

The intervention group showed a statistically significant reduction in menstrual pain compared to the control group.

• Aviva exercise was associated with significantly reduced menstrual pain compared to a control group Kovács Z, Atombosiye E, Hegyi G, Szőke H. Medicina (Kaunas). 2024;60(1):184.
• https://pmc.ncbi.nlm.nih.gov/articles/PMC10821191

Does the Aviva Method affect uterine artery blood flow?

A related 2023 observational study by the same research group used Doppler ultrasound to measure uterine artery pulsatility index before and after the Aviva exercise protocol in the same population.

The intervention group showed a statistically significant change in uterine artery PI compared to the control group (p = 0.011) - confirming that Aviva exercise produces measurable effects on uterine hemodynamics. Menstrual pain reduction was not statistically significant in this cohort; the authors suggest the findings reflect normal acute vascular responses to exercise, with the clinical implications for chronic uterine perfusion continuing to be studied.

Together, these two studies provide complementary evidence: the method demonstrably affects uterine artery blood flow, and in a subsequent clinical study, produced significant pain reduction.

Kovács Z, Hegyi G, Szőke H. Journal of Clinical Medicine. 2023;12(22):7021. https://pubmed.ncbi.nlm.nih.gov/38002635/

Is the Aviva Method being studied in IVF patients?

A pilot study has examined the Aviva Method in IVF patients classified as poor responders. This is early-stage research. The initial findings have not yet been independently published or statistically validated, and the Aviva Method Center has since partnered with an IVF unit to conduct a larger, controlled clinical study testing the method's efficacy in this same patient population.

Reproductive medicine research increasingly recognizes the role of circulation, vascular health, and moderate exercise in reproductive outcomes. The Fertility Class provides a structured, on-demand way for women to incorporate this kind of movement into their daily lives - alongside medical treatment, not as a replacement for it.

The program is used by women at every stage: trying to conceive naturally, managing PCOS or cycle irregularity, preparing for IVF, or working to understand and regulate their hormonal health. It is globally accessible, low-impact, and HSA/FSA eligible in the United States.

For clinicians who want to offer patients an evidence-informed movement option, The Fertility Class is available at www.thefertilityclass.com. 

For how movement is adjusted at each stage of treatment, see our phase-by-phase guide to exercise during IVF and IUI.

Partnership and referral information is available below by continuing to the "Become a Partner" button, or by reaching out to us directly: info@thefertilityclass.com

Last updated: September 2026