Abstract

BACKGROUND: Despite Pilates exercise’s widespread adoption in health promotion, variations in implementation protocols and targeted health outcomes have resulted in fragmented evidence. A synthesis of existing evidence is required to establish evidence-based protocols and its validated effects for women’s health outcomes. PURPOSE: The purpose of this review was to evaluate the characteristics of Pilates exercise interventions, evaluate the methodological quality of existing systematic reviews, estimate Pilates exercise effects on diverse health outcomes, and discuss future Pilates exercise research. METHODS: Two independent researchers conducted a literature search across four databases, following the PRISMA guidelines. After the screening process, eight systematic reviews were included. Additionally, the researchers investigated each systemic review’s included independent studies (n = 40). Quality of appraisal was conducted using the AMSTAR 2 tool, followed by a meta-analysis performed with R software. RESULTS: Analysis of FITT revealed substantial heterogeneity in Pilates exercise interventions. No study adopted theoretical frameworks for guiding intervention development and implementation. Methodological quality assessment rated all systematic reviews low, primarily due to inadequate statistical approaches and insufficient analysis of between-study heterogeneity. There were significant improvements in flexibility (Cohen’s d = 0.74, 95% CI [0.32, 1.16]), cardiorespiratory fitness (Cohen’s d = 0.95, 95% CI [0.41, 1.48]), and labor outcomes (pain: Cohen’s d = -1.29, 95% CI [-1.86, 0.72]; delivery time: Cohen’s d = -0.42, 95% CI [-0.77, -0.08]). CONCLUSION: There is a critical need to develop standardized Pilates exercise protocols tailored to women’s specific health outcomes.

1. Introduction

Pilates exercise is a comprehensive physical conditioning method that emphasizes core stability, muscular strength, flexibility, postural alignment, and controlled breathing ¹ Its biomechanical foundation is grounded in principles of human movement science; each exercise is purposefully designed to improve neuromuscular efficiency and joint mechanics, thereby promoting functional movement patterns and minimizing injury risk ². Moreover, the integration of biomechanical precision and mindful awareness underlies its use in both physical rehabilitation and psychological well-being ^{3, 4, 5}This holistic approach suggests Pilates exercise holds promise as a versatile intervention adaptable to diverse population and fitness levels, including for addressing the complex health needs specific to women.

Globally, women encounter distinct and often disproportionate health challenges arising from a complex interplay of biological determinants, sociocultural dynamics, and systematic inequities ⁶. Biological factors, including the reproductive life cycle (e.g., menarche, pregnancy, postpartum, menopause), hormonal fluctuations, and sex-specific predispositions, contribute to unique health profiles. Women experience higher rates of certain conditions such as depression, anxiety disorders, autoimmune diseases, osteoporosis, and specific musculoskeletal issues such as low back pain ⁷. Sociocultural factors, including unequal power relationships, restrictive gender norms limiting education and employment, an overwhelming focus on reproductive roles, and pervasive gender-based violence, further compound these vulnerabilities ^{8, 9}. Systemic issues, such as gender bias in medical research and healthcare delivery, diagnostic delays for conditions like cardiovascular disease and cancer, and socioeconomic disadvantages, create additional barriers to optimal health ⁶. These challenges are not static but accumulate and interact across a woman’s lifespan; early life exposures and cumulative stressors significantly shape long-term health trajectories, influencing risks for chronic diseases and functional decline in later life ¹⁰. The constant pressure on women to navigate these biological, social, and systemic challenges highlights a critical need for holistic health interventions that address both physical and mental well-being.

The recognition of Pilates exercise potential benefits, combined with its increasing global popularity, has drawn considerable scholarly interest, resulting in an exponential rise in studies investigating Pilates exercise-based interventions for diverse women’s health outcomes (Figure 1). In response to the numerous reports of Pilate exercise-based interventions in the domain of physical activity research, there is a clear need for a comprehensive synthesis and critical appraisal of the existing evidence base. Umbrella reviews provide a methodological solution by systematically synthesizing evidence from multiple systematic reviews and meta-analyses, offering a high-level overview of the existing knowledge, assessing the consistency and quality of evidence, and identifying robust findings and persistent research gaps ¹¹. Therefore, this umbrella review was conducted to synthesize the breadth of evidence from existing systematic reviews and meta-analyses regarding the effects of Pilates exercises across a spectrum of women’s health outcomes. A key aspect of this review involves not only summarizing what is known about the effectiveness of Pilates exercise but also evaluating how this knowledge has been generated. By systematically mapping the characteristics of interventions alongside quantifiable health impacts across existing literature reviews, this study aimed to reveal patterns in research methodology and highlight areas needing more rigorous investigation, thereby informing future research and evidence-based practice guidelines.

Specifically, this umbrella review addressed the following research questions: 1) What are the characteristics (i.e., experimental design, implementation strategies, theoretical frameworks) of Pilates exercise interventions targeting women’s health outcomes as reported in existing systematic reviews and meta-analyses?; 2) what is the synthesized evidence from these reviews on the quantifiable health impacts of Pilates exercise interventions across various physiological and psychological domains relevant to women’s health?’; and 3) what are the key strengths and limitations in the current body of systematic review evidence on Pilates exercise for women’s health?

2. Methods

An umbrella review is a rigorous methodological approach that synthesizes and critically evaluates evidence from multiple systematic reviews into a comprehensive analytical framework ¹². This methodology allows researchers to systematically compare, contrast, and assess the quality, consistency, and strength of conclusions across multiple reviews, thereby producing a higher-level synthesis of the existing results ¹². Given the heterogeneity in reported effects of Pilates exercises on diverse health outcomes ¹³, we applied a focused analytical lens on women in the general population and their associated health outcomes. To strengthen the analytical rigor of this review, we conducted a detailed examination of the primary studies included within each systematic review. This additional layer of analysis was expected to enable the calculation of pooled effect sizes while accounting for inter-study heterogeneity, ultimately providing deeper insights into the effectiveness of Pilates exercise interventions and the variability of their outcomes.

A literature search was conducted across four major electronic databases: PubMed, Cochrane Library, CINAHL, and SPORTDiscus. Citation management and organization were facilitated through the integration of Zotero reference management software and Microsoft spreadsheet application. The development of search strategies benefited from a collaborative partnership between a research team member, who serves as an instructor (SC) for the graduate-level course “Systematic Review and Meta-Analysis,” and a specialized Kinesiology librarian at the university. This expert collaboration ensured the construction of database-specific search queries optimized for each platform’s unique search workflow ¹². The search strategy incorporated both controlled vocabulary (i.e., MeSH terms) for “Pilates” and supplementary keywords including “women” and “female” to ensure comprehensive retrieval of pertinent literature. The detailed search syntax and Boolean operators employed for each database are systematically documented in Table 1. The definitive literature search was concluded on August 27, 2024.

The study selection criteria were established using the PICO (Population, Intervention, Comparison, Outcome) framework ¹⁴. The target population was specifically defined as adult women aged between 18 and 65 years engaging in Pilates exercise. This age range delimitation excludes pediatric and adolescent populations, where developmental factors significantly influence health outcomes, and older adults, where age-related conditions and comorbidities may confound results. This investigation focused specifically on Pilates exercise interventions designed to enhance health and wellness in adult women without acute or chronic illnesses, excluding studies primarily aimed at medical treatment. This limited scope allows for a more focused examination of Pilates’ effectiveness in health promotion rather than treatment purposes. Only systematic reviews and meta-analyses were included to facilitate the synthesis of existing scientific evidence. Studies were excluded if they met any of the following criteria: 1) involved participants currently undergoing active medical treatment or acute rehabilitation, 2) examined mixed-modality exercise interventions that extended beyond pure Pilates exercise, 3) lacked health-related outcome measures including health-related quality of life, physical function, fitness, body composition, or psychological well-being, or 4) were published in languages other than English.

The initial screening process was conducted independently by two researchers (Author 1, Author 2) who evaluated titles and abstracts for relevance. Full-text articles were retrieved when abstracts provided insufficient information for eligibility determination. Any disagreements between two authors were resolved through collaborative discussion to reach consensus. The final selection of studies was determined through independent full-text review by two researchers, applying the predetermined eligibility and exclusion criteria with systematic rigor (Figure 2).

A hierarchical two-tiered approach was employed for data extraction, systematically analyzing characteristics at the review level as well as components of individual studies. The first tier focused on the analysis of the included systematic reviews, encompassing bibliometric information, review methodology, number of included individual studies, key findings regarding Pilates exercise effects on women’s health outcomes, and methodological considerations including protocol variations, study design heterogeneity, and inconsistent outcome measurement. The second tier involved a detailed examination of all individual studies included in the selected systematic reviews. This analysis encompassed study characteristics (e.g., purpose, design, setting), women population demographics (e.g., sample size, participant characteristics, age range), theoretical frameworks, intervention details (e.g., instructor qualifications, Frequency/ Intensity/ Time/Time characteristics, delivery methods), and outcome assessment parameters, statistical approaches, and reported findings. This structured approach ensured comprehensive data capture while maintaining systematic organization of extracted information.

The methodological quality assessment was conducted using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews, version 2), a validated instrument for evaluating systematic reviews of healthcare interventions incorporating both randomized and non-randomized studies ¹⁵. This tool comprises 16 items examining critical methodological aspects, including protocol registration, search strategy, study selection processes, data extraction protocols, risk of bias assessment, and meta-analytical methods. AMSTAR 2’s evaluation framework utilizes seven critical and nine non-critical domains, each assessed on a three-point scale (i.e., “Yes,” “Partial Yes,” or “No”). Moving beyond its predecessor’s numerical scoring system, AMSTAR 2 employs a nuanced approach that evaluates overall confidence in review findings based on performance across critical and non-critical domains, yielding four confidence levels: High, moderate, low, or critically low. For this review, two authors conducted domain-specific assessments, resolved discrepancies through consensus discussions, and applied standardized decision rules to determine final quality ratings.

For continuous outcomes, means and standard deviations were extracted. A random-effect model was employed for meta-analysis, as Pilates exercise interventions included diverse age groups and varied protocols and experimental designs, requiring a model that accommodates this variability. Effect sizes were calculated as standardized mean differences (i.e., Cohen’s d) with 95% confidence intervals (CI), with statistical significance set at p < 0.05. Following Cohen’s criteria (1992), effect sizes were categorized as small (< 0.50), moderate (0.50 – 0.79), or large (> 0.80) ¹⁶. Heterogeneity between studies was quantified using the I² statistics with values of 0 – 25% indicating low heterogeneity, 25 – 50% moderate heterogeneity, and > 50% moderate to high heterogeneity, and τ² statistic ¹⁷.

3. Results

This umbrella review with meta-analysis encompassed eight systematic reviews (Table 2), collectively analyzing their included individual studies (N = 45) (Appendix A). Across these studies, a total of five studies were excluded due to non-English language (n = 3), and inability to retrieve the original paper (n = 2). Finally, a total of 40 individual studies were included in the additional analysis.

The methodological quality assessment using AMSTAR 2 revealed significant limitations across included systematic reviews (Table 3), with an inter-rater agreement of 0.80 between two authors. While basic research design elements were adequately addressed (i.e., research question formulation, duplicate study selection, and data extraction), critical methodological domains showed substantial weaknesses. Fewer than 30% of reviews met criteria for comprehensive literature search strategy, excluded studies documentation, appropriate statistical methods, risk of bias consideration, and publication bias analysis. None of the reviews adequately addressed publication bias or its potential impact on findings, resulting in critically low overall quality ratings. Among the systematic reviews conducting meta-analyses ^{18, 19, 20, 21, 22, 23}, only 16.7% employed appropriate statistical methods, and 33.3% accounted for risk of bias. Notably, 75% failed to incorporate risk of bias assessments in their results interpretation. Overall, 81.3% of AMSTAR 2 criteria (13 out of 16 items) showed compliance rates of 50% or below.

Analysis of 40 Pilates intervention studies in women aged 18-65 revealed predominant use of randomized controlled trials (RCTs) (n = 35, 87.5%) with sample sizes of 11-105 participants. Most studies (n = 30, 85.7%) employed parallel design comparing experimental and control groups. Intervention characteristics showed consistent session frequency (2.3±0.76 times/week, Coefficient of Variation (CV) = 33%) and duration (56±10.8 minutes, CV = 19.2%), though program length varied substantially (11.9±8.4 weeks, CV = 71.0%, Range: 4-48 weeks). Mat-based Pilates dominated (n = 31, 77.5%), followed by equipment-based (n = 6, 15.0%) and combined approaches (n = 1, 2.5%). Two studies did not report any type of Pilates exercise they used ^{24, 25}. Exercise intensity was reported in 42.5% of studies (n = 17), categorized as low (n = 6, 15%) or moderate (n = 11, 27.5%), with 30% (n = 12) providing precise measurements via tools including the Borg RPE scale.

Instructor qualifications were notably underreported, with only one study mentioning “ample experience” without details ²⁶. It also revealed substantial diversity in targeted health outcomes, with 18 outcomes reported across the studies (n = 31, 77.5 %) and 59 appearing in single studies (n = 27, 67.5%). A trend analysis demonstrated an evolution in research focus: Early studies (2007-2012) emphasized rehabilitation and physical function outcomes (i.e., muscle strength, posture, pain management); the intermediate period (2013-2017) expanded to include quality of life and blood lipid profiles; and recent years (2017-2024) introduced labor-related outcomes.

The analysis revealed a lack of theoretical evidence in the Pilates exercise intervention literature: none of the included systematic reviews and their included individual studies examined theoretical frameworks underlying intervention development and implementation.

The meta-analysis was conducted to evaluate Pilates exercise effects across diverse health outcomes, including physical health (i.e., pain, blood lipids, bone mineral density), function and mobility (i.e., 6-min walk test, sit and reach, timed up and go), body composition (i.e., body fat percentage, BMI, body weight), perceived quality of life (i.e., SF-36), pain (i.e., VAS) and labor/postpartum-related variables. The analysis incorporated baseline and post-intervention mean differences and standard deviations, excluding follow-up results due to inconsistent reporting across studies. Detailed results of the meta-analysis are presented in Table 4. The estimated effects of Pilates exercise interventions on women’s health outcomes included significant improvements in flexibility (Cohen’s d = 0.74, 95% CI [0.32, 1.16]) and cardiorespiratory fitness (Cohen’s d = 0.95, 95% CI [0.41, 1.48]). In addition, Pilates exercise showed significant effects in reducing labor pain (Cohen’s d = -1.29, 95% CI [-1.86, -0.72]) and shortening labor time (Cohen’s d = -0.42, 95% CI [-0.77, -0.08]). Conversely, no statistically significant pooled effects were found in pain, quality of life, body composition metrics, blood lipids, and agility. Nevertheless, Pilates exercise demonstrated potential effects on systolic blood pressure and weight gain during pregnancy with high heterogeneity.

4. Discussion

This umbrella review identified methodological and conceptual limitations in the existing literature on Pilates exercise interventions for women’s health. Critical methodological weaknesses were evident across included systematic reviews (N = 8). While intervention characteristics showed consistency in session frequency and modality (i.e., mat-based Pilates), substantial heterogeneity was observed in program duration, intensity prescription, and outcome measures. The evolution of research priorities from physical function to broader wellness dimensions represents progress in Pilates exercise adoption, yet the absence of theoretical frameworks guiding intervention design and implementation remains a significant limitation. These findings highlight the urgent need for theoretically grounded, methodologically rigorous research to advance evidence-based Pilates exercise interventions for women’s health.

Although RCTs dominated the included studies (87.5%), deeper analysis revealed significant methodological limitations beneath this apparent methodological strength. Only 17.1% of studies provided comprehensive randomization and allocation concealment protocols, while a mere 5.7% detailed blinding procedures, undermining the robustness of the reported findings ^{24, 27}. In particular, the lack of standardized methods for prescribing and quantifying exercise intensity emerges as a particularly critical flaw in the reviewed Pilates literature ²⁸. Several factors may contribute to this standardization deficit. Pilates methodology inherently emphasizes control, precision, and mindful execution overachieving maximal exertion or quantifiable loads in the traditional sense. Furthermore, the field may lack validated, Pilates-specific intensity measurement tools. This absence of standardized intensity guidelines presents a significant barrier to study interpretation, replication, and clinical implementation. Future research should incorporate objective measurement tools, such as electromyography (EMG), to quantify exertion levels and muscle activation patterns, thereby establishing Pilates-specific intensity parameters. The development of validated rating scales would enable precise dose-response analyses and facilitate meaningful cross-study comparisons, ultimately advancing evidence-based recommendations for Pilates exercise prescription.

Another significant layer of methodological limitation arises from the inadequate reporting of instructor qualifications and teaching experience ²⁹, Pilates exercise research frequently omits crucial methodological details regarding instructor expertise, a significant oversight given that proper execution of breathing and centering principles influences physiological outcomes. Proper execution, influenced by instructor cueing and correction, as evidenced by studies showing specific breathing techniques significantly increase transversus abdominis activation ³⁰. This evidence underscores instructors’ professional expertise as a critical determinant of intervention efficacy, as proper guidance directly influences physiological outcomes. Future research must address this gap by systematically documenting instructor-related characteristics. This reporting should include details such as the specific training lineage or school (e.g., Classical, Contemporary, Polestar, Balanced Body), the level of certification achieved (e.g., Mat, Reformer, Comprehensive), total hours of training, and years of teaching experience. Where multiple instructors are involved, efforts should be made to standardize training or delivery, or at minimum, statistically account for potential instructor effects in the analysis.

The significant reduction in systolic blood pressure revealed by meta-analysis suggests Pilates exercise’s potential as an alternative to conventional aerobic exercise for cardiovascular health improvement. However, the substantial heterogeneity indicates marked variability across studies, likely attributable to differences in baseline blood pressure (ranging from 105 to 135 mmHg), participant’s developmental stage (i.e., pregnancy and labor), and intervention protocols (varying in equipment use and session duration from 45 to 60 minutes). The imprecise intensity measures and insufficient weekly exercise volumes relative to the American College of Sports Medicine (ACSM)’s recommended 150 minutes ³¹, may contribute to inter-study variability. While interventions met ACSM’s minimum 8-week threshold for physiological adaptation, longer-duration studies are needed to confirm Pilates exercise’s cardiovascular health benefits. Moreover, the prior study discussed that isometric exercise can reduce arterial stiffness through enhanced vascular elasticity, potentially explaining the observed differential effects ³². Based upon this evidence, future Pilates exerciselp-= research can consider employing advanced vascular assessment tools, such as pulse wave velocity measurement via VP-1000 systems, to elucidate Pilates exercise’s specific cardiovascular mechanisms and distinguish between acute hemodynamic responses and sustained vascular adaptations.

The significant improvements in flexibility highlight Pilates exercise’s effects in enhancing hamstring and lumbar extensibility. This pooled effect likely stems from intervention parameters aligning with ACSM guidelines ³³ for flexibility and neuromuscular training. The study contributing the highest weight (65.1%) to the meta-analysis ³⁴ employed higher frequency (4 times/week) and progressive intensity (40-60% HRmax), key factors in promoting tissue elongation and connective tissue adaptation through neuromuscular mechanisms ^{35, 36}. This aligns with the evidence showing eccentric training with progressive loading effectively enhances muscle fascicle length and range of motion ³⁷. Possibly, Pilates exercise’s distinctive emphasis on active eccentric contractions may stimulate myofascial mobility and vascular perfusion—critical components for flexibility enhancement ³⁸. Lastly, the inclusion of specific Pilates motions (e.g., Spine Stretch, Forward Folds, Roll-Up) directly targeting sit-and-reach test requirements likely contributed to the observed large effect size. However, while the sit-and-reach test reliably measures linear static flexibility, it may not capture multi-regional or functional mobility aspects. Future research should incorporate more comprehensive assessment tools, such as Functional Movement Screening (FMS) ³⁹, goniometric measurements (Goniometry) ⁴⁰, to fully evaluate Pilates exercise’s multidimensional flexibility benefits.

The observed reduction in labor pain and labor time highlights Pilates exercise as a potential non-pharmacological, low-impact modality for pregnant women. Our findings align with a previous study reporting Pilates effect in reducing the labor length ⁴¹. Reference ²⁴ also showed a large effect size (Cohen’s d = -1.06) in a short-term intervention (2 times/week, 35 minutes/session) over eight weeks ²⁴. This highlights the benefit of Pilates exercise shown with minimal durations, distinguishing it from general prenatal exercises. This could be attributed to Pilates exercise’s unique approach of neuromuscular coordination through controlled movements with diaphragmatic breathing. A previous study showed that specific breathing patterns (e.g. deep breathing) regulate intra-abdominal pressure by activating core muscles, which could possibly provide rationale for Pilates exercise’s potential benefit in factors relevant to labor progression ^{42, 43}. Furthermore, controlled movements and dynamic stretching of Pilates exercise are in line with principles shown to improve fascial mobility, which may promote elastic recoil, potentially making uterine contractions more efficient during labor ⁴⁴. However, more physical activity research is needed to accurately evaluate how Pilates exercise affects labor progression and efficacy from a biomechanical perspective. In addition, the flexibility and adaptability shown with short duration leading to benefits demonstrate its possibility as a practical exercise for pregnant women who may have physical or time constraints.

5. Limitations

Several limitations were included in this review work. First of all, the substantial heterogeneity observed across seven outcomes could not be addressed through sensitivity or subgroup analyses due to insufficient comparable studies, preventing exploration of potential moderators influencing Pilates’ effectiveness. The limited duplicates in outcome measures and varying assessment methods across studies underscores the urgent need for standardized outcome sets and intervention protocols to enhance research comparability and replication. Furthermore, while focusing on healthy adult women enabled more reliable comparisons across studies, this population restriction may limit the generalizability of results for more diverse women groups. Finally, the significant effects of Pilates exercise on labor pain and time should be cautiously interpreted due to potential confounding features such as the use of epidural anesthesia or infusion of oxytocin.

6. Conclusion

This umbrella review with meta-analysis discussed both the promise and limitations of Pilates exercise interventions for women’s diverse health outcomes. Meta-analyses demonstrated significant improvements in physical function domains, particularly flexibility and cardiorespiratory fitness, and notable benefits for labor-related outcomes. However, the review identified critical gaps in current Pilates exercise intervention research, including inconsistent methodological quality, lack of theoretical frameworks, and substantial heterogeneity in intervention protocols. To advance the field, future research should prioritize: (1) development of standardized, evidence-based Pilates exercise protocols with clear implementation guidelines, (2) incorporation of theoretical frameworks to strengthen intervention design and explain underlying mechanisms, and (3) rigorous methodological approaches with standardized outcome measures. These improvements would enhance the quality of evidence supporting Pilates as an effective exercise modality for women’s health promotion and provide clearer guidance for clinical practice.

References