Physical Activity During Assisted Reproduction: Scientific Evidence, Mechanisms, and Clinical Implications

Abstract

Assisted reproductive technologies (ART) have transformed infertility management, yet multiple modifiable lifestyle factors, including physical activity, may influence clinical outcomes. This review synthesizes current evidence regarding the impact of physical activity during assisted reproduction, addressing epidemiology, pathophysiology, risk factors, clinical features, diagnostic approaches, management strategies, recent advances, and contemporary guideline recommendations. Mechanistic insights and clinical implications are highlighted to guide healthcare professionals in optimizing care for patients undergoing ART.

Introduction

Assisted reproductive technologies, such as in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), are increasingly utilized for the management of infertility. With the growing global burden of subfertility, there is a pressing need to optimize ART outcomes. Lifestyle factors, particularly physical activity, have garnered interest as modifiable determinants of reproductive success. Despite common patient concerns regarding exercise during fertility treatment, scientific evidence suggests a nuanced relationship between physical activity, reproductive physiology, and ART outcomes. This review aims to provide a comprehensive, evidence-based synthesis for clinicians managing patients in this context.

Epidemiology / Disease Burden

Infertility affects 8-12% of reproductive-aged couples worldwide, with ART cycles increasing annually. The global shift towards delayed childbearing and rising obesity rates compound the prevalence of subfertility, highlighting the need for optimized ART protocols. Sedentary behavior, prevalent in modern societies, is associated with adverse metabolic and reproductive outcomes. Conversely, the role of physical activity as a potential modifiable factor in ART success has become an area of active research. Epidemiological studies estimate that 30-40% of women undergoing ART engage in some form of regular physical activity, yet the intensity and type vary considerably.

Pathophysiology

Physical activity influences reproductive physiology through multiple mechanisms. Moderate exercise is associated with improved insulin sensitivity, regulated hypothalamic-pituitary-gonadal (HPG) axis function, reduced systemic inflammation, and enhanced endometrial receptivity. Exercise-induced modulation of adipokines, myokines, and sex steroids may positively affect folliculogenesis and oocyte quality. Conversely, excessive physical activity can disrupt gonadotropin secretion, leading to anovulation, luteal phase defects, and impaired implantation. The pathophysiological balance between beneficial and detrimental effects of exercise during ART is influenced by individual baseline characteristics, including body mass index (BMI), metabolic profile, and pre-existing reproductive disorders.

Risk Factors

Risk factors that may modulate the impact of physical activity during ART include obesity, polycystic ovary syndrome (PCOS), metabolic syndrome, advanced maternal age, and pre-existing sedentary lifestyle. Overweight and obese women may benefit most from moderate-intensity exercise, given the associated improvements in insulin sensitivity and inflammatory milieu. Conversely, women with low BMI or a history of vigorous endurance training are at increased risk for hypothalamic-pituitary dysfunction if excessive exercise is continued during ART. Tailoring physical activity recommendations based on these risk factors is critical for optimizing outcomes.

Clinical Features

Clinically, the interplay between physical activity and ART may manifest in variations in ovarian response, oocyte quality, endometrial thickness, and implantation rates. Women who engage in moderate physical activity prior to and during ART cycles often demonstrate improved metabolic profiles and psychological well-being, which may indirectly enhance ART outcomes. Symptoms of excessive exercise, such as menstrual irregularity, fatigue, and decreased bone density, should prompt clinical reassessment and possible modification of exercise regimens during ART.

Diagnosis

Assessment of physical activity in patients undergoing ART should include a detailed history of exercise frequency, intensity, duration, and type. Validated tools, such as the International Physical Activity Questionnaire (IPAQ), can aid in quantifying baseline activity levels. Laboratory assessment may include evaluation of gonadotropins, estradiol, insulin sensitivity, and markers of inflammation. Ultrasound monitoring of follicular development and endometrial receptivity, alongside careful cycle tracking, remain critical components of ART protocols.

Treatment & Management

Management strategies should individualize physical activity recommendations based on patient risk factors, baseline activity, and ART protocol. Moderate-intensity aerobic exercise (e.g., brisk walking, cycling) for 30-60 minutes most days per week is generally safe and may confer metabolic and psychological benefits. Excessive, high-intensity endurance exercise should be avoided, especially in women with low BMI or a history of menstrual disturbance. Collaboration with exercise physiologists and nutritionists can optimize patient counseling and adherence. Psychological support may address anxiety related to fertility and physical activity.

Recent Advances / Emerging Therapies

Recent studies have focused on the timing, intensity, and type of physical activity during ART. Randomized controlled trials suggest that moderate exercise, initiated prior to or during ovarian stimulation, may enhance endometrial receptivity and live birth rates, particularly in overweight or obese women. Emerging data indicate that mind-body practices, such as yoga and tai chi, may reduce ART-related stress and improve physiological outcomes. Wearable activity trackers and digital health interventions are being investigated as tools to monitor and optimize physical activity during fertility treatment.

Guideline Recommendations

Guidelines from leading reproductive societies, including the American Society for Reproductive Medicine (ASRM) and the European Society of Human Reproduction and Embryology (ESHRE), emphasize the importance of maintaining a healthy lifestyle during ART. Moderate physical activity is recommended, with caution against extreme intensities. Individualized counseling is advocated, particularly in women with metabolic syndrome, PCOS, or underweight status. Clinicians are encouraged to assess and address lifestyle factors as part of comprehensive fertility care.

Conclusion

Physical activity represents a modifiable factor with the potential to positively influence ART outcomes when tailored appropriately. Moderate exercise may improve metabolic and reproductive parameters, while excessive activity can be detrimental in select populations. Clinicians should provide evidence-based, individualized guidance on physical activity during assisted reproduction, integrating recent advances and guideline recommendations to optimize patient care and reproductive success.