Sage Journals: Discover world-class research

Abstract

Spanish

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age. Most patients present insulin resistance (IR) and impaired VO₂max associated with cardiovascular mortality. While exercise is recommended as the first-line treatment, there is a lack of certainty of the exercise intensity effect on improvement of pathogenic factors. The aim of the study was to determine the effect of MICT on VO₂max and HOMA-IR compared to other exercise intensities in women with PCOS. Search was performed on PubMed, Scopus and Web of Science during February 2025. Eligible studies included RTCs, women with PCOS diagnosis, moderate-intensity training and/or other intensities intervention lasting ≥8 weeks, and VO₂max measured by direct method. Meta-analyses included 10 studies involving 289 participants. MICT improved cardiorespiratory capacity as follows: 4.65 mL/kg/min, 95% CI: 3.07-6.23 P < 0.001, I² = 84% n = 9; and HIIT: 3.55 mL/kg/min, 95% CI: 1.84-5.26, P < 0.001, I² = 0% n = 4. No effect was seen on HOMA-IR with MICT: 0.06, 95% CI: −0.67-0.78 P < 0.88, I² = 0% n = 3; or HIIT: −0.20, 95% CI: −0.70-0.31, P < 0.44, I² = 0% n = 3. In conclusion, MICT appears to promote greater changes of VO₂max than HIIT and none of those exercises had a significant impact on IR.

Keywords

polycystic ovary syndrome cardiorespiratory capacity insulin resistance moderate-intensity continuous training exercise

“In addition to the androgen excess, the high prevalence of IR and its association with cardiopulmonary impairment could increase the risk for cardiometabolic disease.”

Introduction

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age. Its global prevalence of 9.2% differs according to Rotterdam diagnosis criteria.^1,2 Clinical presentation is heterogeneous and can be categorized in several phenotypes involving symptoms such as hirsutism, alopecia, acne, irregular menstrual cycles and reduced fertility.³ Although PCOS is mainly a hyperandrogenic disorder, evidence suggests a strong association to insulin resistance (IR) and its compensatory hyperinsulinemia.^4,5 IR affects adipose tissue and skeletal muscle, favoring adipocyte dysfunction with low grade of inflammation and impaired muscle mitochondrial function compared to their counterparts without PCOS.⁶ While IR is not a diagnosis criteria, 37.5% of women with PCOS present this condition.⁷ Metabolic dysfunction along with other health-related issues like abdominal obesity, sedentary lifestyle and poor diet facilitates androgen secretion in a vicious circle that worsens the underlying hormonal disturbances.⁸ Therefore, insulin sensitivity not only plays a crucial role in the pathophysiology of PCOS but also in its treatment.^9,10

PCOS is a significant concern in women’s health. Patients are at a higher risk of developing metabolic syndrome, diabetes mellitus, cardiovascular diseases and cancer compared with age-matched and Body Mass Index-matched controls.^11,12 Evidence indicates that overweight/obese PCOS women usually present an impaired cardiorespiratory capacity measured as maximal aerobic capacity (VO₂max). VO₂max is a very important indicator of the patient’s ability to sustain physical activity and impacts not only on exercise adherence, but also on quality of life. Some studies had observed an inverse correlation between IR and VO₂max in overweight and obese women with PCOS¹³ which could be associated with mitochondrial dysfunction.^14,15 Low levels of VO₂max may be related to an increase in autonomic sympathetic tone, decrease vagal tone¹⁶ and could be linked to the androgenic pattern in PCOS patients.¹⁷ Moreover, diminished functional capacity may perpetuate IR over time and increase cardiovascular mortality risk.¹⁸

While no universal therapy for PCOS is available, lifestyle modifications (including dietary changes, physical activity or both) are considered as the first line of intervention.¹⁹ Exercise has been shown to reduce adipose tissue and IR, which contributes to reducing hyperandrogenism. Promoting normal endocrine and adrenal functions may result in a complete recovery from the clinical characteristics of PCOS.^20,21 Studies have reported that exercise training can substantially improve VO₂max and other metabolic markers including insulin sensitivity measured by homeostatic model assessment of insulin resistance (HOMA-IR).²² The improvement in physical conditioning leads to increased tissue sensitivity to insulin and reduces cardiovascular risk factors in persons with IR.²³

The international evidence-based guidelines for the assessment and management of PCOS recommends 150 min/week of moderate intensity or 75 min/week of vigorous intensity exercise for all women with PCOS.¹⁹ In addition, results from a systematic review advised women with PCOS to engage at least 90 min of moderate intensity continuous training (MICT) at 60%–70% of VO₂max per week to reduce cardiometabolic problems.²⁰ Nonetheless, authors suggest that higher intensities may offer superior metabolic health benefits and serve as a more time-efficient alternative to traditional endurance training.^24-26 Therefore, the aim of the present study was to determine the effect of MICT on VO₂max and HOMA-IR in comparison to other exercise intensities in women with PCOS.

Methods

Protocol and Registration

This meta-analysis was approved and registered on Prospero International Prospective Register of Systematic Reviews (CRD42024623712).

Search Strategy, Study Selection and Data Extraction

We performed a systematic search of all publications up to February 2025 using Pubmed, Scopus and Web Of Science databases. This review was carried out in accordance with the guidelines on Cochrane Handbook for Systematic Reviews of Interventions and with PRISMA statements for the reporting of systematic reviews.²⁷ Figure 1 shows the PRISMA flow diagram for study selection. MeSH terms and free-text were used to perform the search (Appendix A), and the reference lists of other review articles were explored using snowballing methods to identify other potential eligible studies. The search was restricted to full text available articles in English or Spanish.

Figure 1.

PRISMA flow diagram for study selection.

Initial study selection and screening process was completed by 1 reviewer (MFC). After removing duplicate articles, title and abstract were examined to identify the inclusion criteria. Subsequently, 2 authors (MFC and BOR) independently completed full-text screening. Any discrepancies were resolved by consensus or by arbitration from a third reviewer (LGD). The remaining articles were compared and selected based on the population, intervention, comparison, outcome, and type of study (PICOS).

Based on eligibility criteria (Table 1), studies involved premenopausal women aged 18-40 years with diagnosis of PCOS. Interventions included RCTs, pre-experimental or quasi-experimental with a pre-post design and had to report a moderate-intensity continuous training protocol lasting at least 8 weeks. Exercise intensity was categorized according to Garber and collaborators.²⁸ We excluded concurrent/resistance training, dietary manipulation or drug intervention that may affect the outcomes measures. Comparison groups consisted of either a no-exercise control group or any other intensity training. The primary outcome specified for the meta-analysis was changes in aerobic capacity measured by maximal or peak oxygen consumption, determined exclusively via direct breath-by-breath respiratory gas analysis. The secondary outcome was IR assessed using the HOMA-IR. Rayyan Systematic Review (Rayyan: AI-Powered Systematic Review Management Platform), a web-based platform, was used to count, screen and store the data obtained during the study.

Table 1.

Eligibility Criteria Established by PICO Methodology: Participant, Intervention, Comparison and Outcome.

Participant	Intervention	Comparison	Outcome
PCOS diagnosis by any established criteria Premenopausal women aged 18-40	Moderate-intensity exercise: 40%-59% %HRR, 64-76 %HRmax or 46-63 VO₂max	MICT vs other intensity or no exercise group	Primary: Cardiorespiratory capacity (VO₂max) Secondary: Insulin resistance (HOMA-IR)

PCOS, polycystic ovary syndrome; %HRR, percent of heart rate reserve; %HRmax, percent of maximal heart rate; VO₂max, maximal aerobic capacity; MICT, moderate-intensity continuous training.

Risk of Bias (Quality) Assessment and Certainty of Evidence

Two authors (MFC and BOR) independently assessed the risk of bias in the trials using guidance outlined in the Cochrane tool for risk of bias assessment with RoB 2. Bias was evaluated as a judgment (high, low or unclear) for 5 domains including selection, performance, attrition, reporting and others. Overall risk-of-bias assessment and categorization were determined and expressed as High risk of bias, Low risk of bias or Some concerns. Same authors assessed the certainty of the evidence using the GRADEpro® framework.

Data Synthesis, Subgroups Analysis and Sensitivity

All outcomes were analyzed using Cochrane’s Review Manager (RevMan Version: 8.18.0). Continuous data were input as means, standard deviation (SD) and sample size. When studies reported standard error of the mean (SEM), SD was calculated according to Cochrane Handbook.²⁹

Data were excluded from meta-analysis if results were presented only as medians with ranges, or if non-parametric statistical analyses were used. Forest plots of the intervention effect were estimated, and their 95% confidence intervals (CIs) were created for each meta-analysis. Subgroup analyses were conducted to compare the effects of MICT with either no-exercise control groups or with other exercise intensities. Data were pooled using fixed-effect or random-effects models, depending on the level of heterogeneity, which was considered important if I²> 50%. Sensitivity analyses were performed to assess the robustness of the results and the influence of each study on the pooled estimates. Publication bias was assessed visually using a funnel plot graph and statistically using the Egger’s test, performed in RStudio.³⁰

Results

The systematic search in literature (Figure 1) returned 31 records from the databases and reference lists. After removing duplicates and studies that did not qualify by title/abstract, 17 full-text articles were assessed by eligibility. Of these, 8 records were excluded for different reasons. Finally, a total of 10 articles were included. In line with the specific purpose of this review, we only included MICT and HIIT interventions as pre/post values. A total of 13 interventions were extracted from these 10 studies, where 6 of them applied a MICT protocol with a no-exercise control,^31-36 3 compared MICT vs HIIT protocol,^37-39 and 1 study evaluated HIIT against both Strength training and a no-exercise group.⁴⁰

Participant and Intervention Characteristics

The included studies comprised a total of 289 participants. Baseline characteristics are summarized in Table 2. All participants were diagnosed by Rotterdam 2003 criteria for PCOS. The mean age ranged from 22.8 ± 3.7 to 32.5 ± 6.2 years old and body mass index (BMI) ranged from 27.7 ± 5.7 to 38.4 ± 9.3 kg/m².

Table 2.

Main Characteristics of Included Studies.

Author/year	Participants	Groups	Exercise	Duration/Frequency	Cardiorespiratory test/used equipment
Costa E. (2018)³¹	Age (yrs): 27.6 ± 4.6 BMI (kg/m²): 32 ± 4.2		SupervisedWalking, jogging, cycling outdoor (self-selected)	16 weeks3 days/week	Breath expired respiratory gases on treadmillPortable metabolic system
		MICT	40 min weekly progressive from 60% to 85% HRmax
		Control	No-exercise
Giallauria F. (2008)³²	Age (yrs): 22.8 ± 3.7BMI (kg/m²):29.2 ± 2.9		SupervisedHospital ambulatory regimenBicycle ergometer	3 months3 days/week	Breath expired respiratory gases on treadmillStationary metabolic system
		MICT	30 min at 60%-70% VO₂max
		Control	No-exercise
Orio F. (2008)³³	Age (yrs): NRBMI (kg/m²): 28.9 ± 3.0		SupervisedHospital ambulatory regimenBicycle ergometer	24 weeks3 days/week	Breath expired respiratory gases on bicycle ergometerStationary metabolic system
		MICT	30-40 min at 60%-70% VO₂max
		Control	12 weeks detrained period
Vince R (2020)³⁴	Age (yrs): 28.0 ± 6.7BMI (kg/m²): 31.15 ± 6.3		SupervisedTreadmill	8 weeks3 days/week	Breath expired respiratory gases on treadmillStationary metabolic system
		MICT	50 min at 60% VO₂max
		Control	No-PCOS patients with same exercise intervention
Halama A. (2019)³⁵	Age (yrs): 28.2 ± 1.9BMI (kg/m²): 29.4 ± 1.6		SupervisedTreadmill	8 weeks3 days/week	Breath expired respiratory gases on treadmillNR
		MICT	60 min at 60% VO₂max
		Control	No-PCOS patients with same exercise intervention
Vigorito C. (2007)³⁶	Age (yrs): 21.7 ± 2.3BMI (kg/m²): 29.3 ± 2.9		SupervisedHospital ambulatory regimenBicycle ergometer	3 months3 days/week	Breath expired respiratory gases on bicycle ergometerStationary metabolic system
		MICT	30 min at 60%–70% VO₂max
		Control	No-exercise
Patten R. (2022)³⁷	Age (yrs): 32.5 ± 6.2BMI (kg/m²): 38.4 ± 9.3		SupervisedCycle ergometer	12 weeks3 days/week	Breath expired respiratory gases on bicycle ergometerStationary metabolic system
		MICT	45 min at 60%-75% HRmax
		HIIT	Twice weekly: 12 × 1 × 1 (90%–100% HRmax and light lead activity recovery). Once weekly: 8 × 4 × 2 (90%–95% HRmax and light lead activity recovery)
Benham J. (2021)³⁸	Age (yrs): 29.2 ± 4.7BMI (kg/m²): 31.4 ± 8.4		Partial superviseSelf-selected aerobic equipment	26 weeks3 days/week	Breath expired respiratory gases on treadmillStationary metabolic system
		HIIT	10 × 30 × 90 (90% HRR and low-intensity)
		MICT	40 min at 50-60%HRR
		Control	Usual level of physical activity
Philbois S. (2022)³⁹	Age (yrs): 29 ± 5BMI (kg/m²): 27.7 ± 5.7		SupervisedTreadmill	2 weeks familiarization16 weeks3 days/week	Breath expired respiratory gases on treadmillPortable metabolic system
		HIIT	2 × 3 (85%-90%HRR and 65%-70%HRR). Total of 35-45 min per session
		MICT	50 min at 70%-80% HRR
		Control	No-exercise
Almenning I. (2015)⁴⁰	Age (yrs): 27.2 ± 5.5BMI (kg/m²): 26.7 ± 6.0		Partial superviseSelf-selected equipment (Treadmill or outdoor walking/running/cycling)	10 weeks3 days/week	Breath expired respiratory gases on treadmillStationary metabolic system
		HIIT	Twice weekly: 4 × 4 × 3 (90%–95% and 70% HRmax). Once weekly: 10 × 1 × 1 (90%–95% and 70% HRmax)
		Strength	3 sets-10 reps of 75% (1RM)Dynamic strength drills
		Control	General exercise recommendations

BMI: body mass index; MICT: moderate-intensity continuous training; HIIT: high-intensity interval training; NR: not reported; HRR: heart rate reserve; HRmax: maximal heart rate; VO₂max; maximal aerobic capacity; 1RM: one repetition maximum

Interventions extended from 8 to 24 weeks. The 16-week program was most common (n = 3) and exercise frequency was generally 3 sessions per week. MICT protocol fluctuated between 30 and 50 min with intensities prescribed at 60% to 80% prescribed as HRmax,^31,37 HRR^38,39 or %VO₂max.^32-36 HIIT sessions ranged between 20 and 50 min involving intensities from 65%-70% up to 90%–100% of HRmax^37,40 or HRR.^38,39 Exercise modalities included between cycle ergometer, treadmill walking/running and outdoor walking/running. One study allowed for participants to choose their desired aerobic equipment.

Cardiorespiratory capacity was measured using expired gas analysis performed on a treadmill (n = 7)^{31,32,34,35,38-40} and on a bicycle ergometer (n = 3).^33,36,37 Two of the included studies employed a portable metabolic system.^31,39 All results were reported as VO₂max in mL/kg/min.

Risk of Bias and Risk of Publication Bias

The results of risk of bias assessment by RoB2 are presented in Figure 2. Three studies scored an unclear or high risk of bias on 2 or more domains^31,33,35 while 7 studies had low risk or only one domain of concern.^32,34,36-40 The overall certainty on evidence is summarized in Table 3. There was a very low certainty of evidence for the effect of MICT on cardiorespiratory capacity when compared to other intensities. Also, there was low certainty for its effect on IR (HOMA-IR) in women with PCOS.

Figure 2.

Risk of bias summary by RoB2.

Table 3.

Assessment of Certainty of Evidence Summary.

Moderate-intensity exercise compared to others intensities for cardiorespiratory capacity and insulin resistance
Patient or population: Women with PCOSSetting:Intervention: Moderate-intensity exerciseComparison: others intensities

Outcomes	Anticipated absolute effects^a (95% CI)		No. of participants (studies)	Certainty of the evidence (GRADE)	Comments
Outcomes	Risk with others intensities	Risk with Moderate-intensity exercise	No. of participants (studies)	Certainty of the evidence (GRADE)	Comments
Improvement of cardiorespiratory capacity (VO2max) reported in ml/kg/min	The mean improvement of cardiorespiratory capacity was 3.55 mL/kg/min	MD 4.65 mL/kg/min higher (3.07 higher to 6.23 higher)	280 (10 RCTs)	⨁◯◯◯Very low^b,c,d,e	Moderate-intensity exercise may increase cardiorespiratory capacity in women with PCOS.
Insulin resistance (IR) assessed with: HOMA-IR	The mean insulin resistance was −0.20 HOMA-IR	MD 0.06 HOMA-IR higher (0.67 lower to 0.78 higher)	95 (4 RCTs)	⨁⨁◯◯Low^d,e,f,g	It is unlikely that moderate-intensity exercise elicits meaningful changes in HOMA-IR in women with PCOS.

CI: confidence interval; MD: mean difference.

GRADE Working Group grades of evidence.

High certainty: we are very confident that the true effect lies close to that of the estimate of the effect.

Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.

Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect.

Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

^aThe risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

Explanations.

^b4 of 10 included studies had an unclear or high risk of bias for random sequence generation, and 3 of 10 included studies had an unclear or high risk of bias for incomplete outcome data.

^cModerate-intensity had probably high heterogeneity.

^dDifferent protocols of moderate-intensity training ranged between 30 and 50 min per session and involved intensities between 60% and 80% prescribed as HRmax, HRR or %VO2max.

^eDifferent protocols of HIIT ranged between 20 and 50 min per session, involved intensities between 90%–100% and intervals of active recovery at 65% to 70% prescribed as HRmax or HRR.

^f2 of 4 included studies had unclear or high risk of bias for incomplete outcome data.

^gSmall sample size included.

Funnel plot graph showed there was probably a high risk of publication bias in the overall report for VO₂max, Figure 3A. After Egger’s test, low risk of publication bias was obtained (P = 0.238), see Figure 3B. Funnel plot symmetry showed probably risk of publication bias in HOMA-IR (Figure 3C), but Egger’s test indicated low risk (P = 0.5352; Figure 3D).

Figure 3.

Risk of publication for: (A) cardiorespiratory capacity; (B) Egger’s test for: cardiorespiratory capacity (P = 0.238); Risk of publication for: (C) HOMA-IR; Egger’s test for: (D) HOMA-IR (P = 0.5352).

Meta-Analysis

A total of 13 interventions were included in the meta-analysis. All studies reported pre and post values for cardiorespiratory capacity (VO₂max) and only 6 interventions reported additional changes on IR assessed by HOMA-IR.^31,38-40

When compared with baseline, exercise significantly improved VO₂max (4.45 mL/kg/min, 95% CI: 3.17-5.73, P < 0.001, I² = 77%), see Figure 4A. After sensitivity analyses, 2 studies were removed.^33,35 Nonetheless the effect size remained significant (4.61 mL/kg/min, 95% CI: 3.61-5.62, P < 0.001, I² = 37%). We attributed it due the shortest and longest time intervention characteristics (8 weeks and 24 weeks). Since there was low risk of publication given by Egge´s test, these studies were retained in the final analysis. No significant changes on HOMA-IR values were observed after exercise interventions (−0.12, 95% CI: −0.53 – 0.30, P < 0.59, I² = 0%), see Figure 4B.

Figure 4.

Effect of exercise (pre/post) for change in: (A) cardiorespiratory capacity (mL/kg/min) n = 13; (B) insulin resistance (HOMA-IR) n = 6.

Sub-Analyses

For primary outcome, 3 studies provided sufficient data to compare the effect of MICT vs HIIT on cardiorespiratory capacity.^37-39 Both protocols resulted in insignificant improvements in VO₂max (Figure 5). MICT: 4.65 mL/kg/min, 95% CI: 3.07-6.23 P < 0.001, I² = 84% n = 9 Figure 5A, HIIT: 3.55 mL/kg/min, 95% CI: 1.84-5.26, P < 0.001, I² = 0% n = 4 Figure 5B. However, neither MICT nor HIIT produced statistically significant change in HOMA-IR when compared with baseline (Figure 6). MICT: 0.06, 95% CI: −0.67-0.78 P < 0.88, I² = 0% n = 3 Figure 6A, HIIT: −0.20, 95% CI: −0.70-0.31, P < 0.44, I² = 0% n = 3 Figure 6B.

Figure 5.

Sub-Analyses: Effect of (A) MICT (pre/post) n = 9, and (B) HIIT (pre/post) n = 4, for change in cardiorespiratory capacity.

Figure 6.

Sub-Analyses: Effect of (A) MICT (pre/post) n = 3, and (B) HIIT (pre/post) n = 3, for change in insulin resistance (HOMA-IR).

Discussion

We evaluated the effect of MICT on VO₂max and HOMA-IR in comparison with different exercise protocols or no-exercise in women with PCOS. 13 protocols involving a total of 289 participants were included in the meta-analyses. When compared with baseline, results showed that exercise significantly improves VO₂max. Along with other studies, this improvement may contribute to reducing cardiovascular risk⁴¹ and risk of mortality⁴² on PCOS patients. The overall results were not affected by the study of Benham et al³⁸ even though their 24-week intervention did not significantly change VO₂max neither by MICT nor by HIIT. These results may be attributed to the reduce adherence reported in the last 3 months of the intervention (64% and 44% median exercise adherence for MICT and HIIT respectively). Despite this, most studies included in this review provide up-to-date evidence that exercise had a beneficial influence on enhancing cardiorespiratory capacity in women with PCOS.

Previous systematic reviews have shown the efficacy of exercise for improving an array of cardiorespiratory fitness outcomes. This review and meta-analysis goes beyond by providing VO₂max values exclusively measured by breath-by-breath respiratory gas analysis. This direct method provides more certainty in the results to be analyzed than when indirect methods are included such as Multistage fitness test or the 6-min walking test. In the current study, changes in VO₂max varied between intensities and training periods. MICT showed modest improvement in VO₂max (1.80 mL/kg/min) after 8 weeks of training at 60% VO₂max.³⁵ Greater values (8.10 mL/kg/min) were obtained after 24 weeks of a supervised aerobic exercise at similar intensities (60%-70% VO₂max).³³ In that study, authors also evaluated the effects of a training program after its cessation, showing that 12 weeks of detraining resulted in a complete loss of all favorable adaptations obtained from exercise. This suggests that not only increasing training period could improve cardiorespiratory fitness but also exercise might be maintained through life for its benefits to be preserved.

Although both MICT and HIIT protocols were effective in increasing VO₂max, the role of duration, intensity and frequency in mediating the favorable impact of exercise has been explored in women with PCOS. Cardiorespiratory sub-analyses suggest that greater mean difference values are obtained by MICT protocols rather than HIIT. These findings are supported by previous meta-analyses reporting larger VO₂max increases with MICT (5.33 mL/kg/min, P < 0.001) than with HIIT (2.87 mL/kg/min, P < 0.001).⁴³

HIIT has been increasingly studied as an emerged alternative. It has been recognized as a time-efficient additional exercise to traditional endurance training by the exercise-based international guidelines for managing type 2 diabetes.⁴⁴ The current review supports its effectiveness in improving VO₂max especially in protocols that involved short periods of exercise above 85% HRmax with intervals of light activity recovery. The efficacy of HIIT on cardiorespiratory capacity has been related to the improving pulmonary ability to take in oxygen for distribution to working skeletal muscle during exercise.⁴⁵ Other colleagues have proved that even in healthy sedentary subjects, a low volume of HIIT is enough to increase mitochondrial respiratory capacity in skeletal muscle with comparable adaptations to endurance training.⁴⁶ It is important to say that variability in HIIT protocols (intensity, duration, frequency, and the type of exercises employed) makes it challenging to standardize its effects on VO₂max. Nonetheless, our findings suggest that HIIT is a viable strategy for improving cardiorespiratory function in women with PCOS.

Regarding the secondary outcome, we evaluated the effect of exercise on IR. Recent data has found that cardiorespiratory fitness may be strikingly impaired in women with PCOS and this may be linked to insulin resistance in overweight and obese women with PCOS.⁴⁷ Some studies have found a relationship between VO₂max and HOMA-IR or some other IR markers (glucose to insulin ratio, glucose or insulin area under curve, etc.).^32,33 Also, an inverse association between VO₂max and HOMA index was described by using univariate and multiple regression analyses.⁴⁸ In contrast to that, the present meta-analysis showed that exercise did not significantly reduce HOMA-IR. Previous analysis⁴⁹ had also found no significant effect of exercise in the post intervention group (−0.22 mL/kg/min, 95% CI: −0.80.0.36, P < 0.004). These results may be attributed due to possible changes in the patient’s diet which were not assessed in studies and could influence the results. In managing PCOS, lifestyle modifications, involving dietary are recommended to ameliorate metabolic perturbation. When combining exercise and diet, it has proved to be more effective than exercise alone for reduction of IR.⁵⁰

Searches in overweight/obesity subjects without PCOS have found HIIT to be as effective as MICT in improving most glucose and insulin resistance markers,^51,52 others have revealed a more robust increase of proteins activity related to glycolytic metabolism by HIIT when compared to continuous medium- to low-intensity exercise.⁵³ In accordance with that, our sub-analyses showed that women with PCOS had greater reductions in HOMA-IR after HIIT compared to MICT. The positive effect of HIIT on blood glucose has been reported in adults with IR or type 2 diabetes^54,55 but also has proved its efficacy on aerobic performance, anthropometric indices and insulin sensitivity in PCOS patients.⁵⁶ On the other hand, the intensity and volume of exercise may provide distinct health benefits in women with PCOS⁵⁷ and some authors also observed improvements in insulin sensitivity parameters by MICT with enough sensitivity. In their study,⁵⁸ 8-weeks exercise showed a significant improvement of VO₂max in PCOS patients while healthy control did not. Yet, HOMA index did not difert between groups.

Some authors support the hypothesis that PCOS patients exhibit an abnormal mitochondrial function involved in the occurrence and development of IR and hyperandrogenism.⁵⁹ By contrast, studies examining mitochondrial changes with exercise in women with PCOS are limited and have not been able to demonstrate an improvement in mitochondrial characteristics.⁶⁰

To date, there is a gap in the knowledge about the underlying exercise response mechanisms associated with improvements in IR. Yet, the impact of either MICT or HIIT in IR suggest not to be unique in women with PCOS. Current data suggest that this response to exercise could be possibly linked to increased fat oxidation and a reduction in intramyocellular fat metabolites which would improve IR.⁵⁷ Further evidence is needed to elucidate the physiological mechanisms linked to exercise response.

Limitations

We believe this study has some limitations worth mentioning. First, the certainty of evidence for primary and secondary outcomes was very low and low respectively, limiting the strength of confidence in the recommendations that can be drawn from these studies. The quality of evidence was downgraded due to the majority of studies demonstrating unclear or high risk of bias on domains like random sequence generation and selective reporting data. Second, few studies have evaluated the effect of exercise on VO₂max by direct method. Further research based on breath expired gases analysis is needed to determine exercise-induced improvements in cardiorespiratory capacity and IR in women with PCOS. Third, the included studies varied in duration, ranging from 8 to 26 weeks, and showed differences in session duration, intensity and equipment used to conduct the exercise protocols. This was particularly evident in HIIT protocols where there is considerable heterogeneity among protocols which can influence the results.

Despite these limitations, it is important to highlight that the present review incorporated a comprehensive search strategy based on international publication guidelines. Also, we included only RTCs which are considered the gold-standard design for determining causality and performed sensitivity analyses to explore heterogeneity and publication bias. Our findings provided an up-to-date synthesis of current evidence regarding the effects of MICT and HIIT interventions in women with PCOS.

Conclusions

PCOS is a common endocrine disorder affecting young women. In addition to the androgen excess, the high prevalence of IR and its association with cardiopulmonary impairment could increase the risk for cardiometabolic disease. This meta-analysis demonstrates that exercise, whether at moderate or high intensity, plays a beneficial role in cardiorespiratory capacity. In particular, MICT appears to promote greater changes of VO₂max than HIIT. Such benefits may ultimately contribute to improving the metabolic and reproductive health of women with PCOS. However, HIIT also appears to be a viable alternative to MICT due to its impact on cardiorespiratory fitness. Despite the time-efficient characteristics, further evidence is needed to determine which specific HIIT protocol provides the most benefit for the PCOS population.

In addition to the fact that current studies are limited in providing a definitive intensity for exercise prescription in women with PCOS, it would also be of great interest to include studies that report diet as a relevant variable for IR.

Thought the growing interest for determining the best exercise prescriptions for women with PCOS, we consider that it’s important to not only increase their physical activity but promote adherence to lifestyle changes. Otherwise deconditioning would lead to the loss of all the beneficial effects of exercise and the clinical characteristics of PCOS could return.

Supplemental Material

Supplemental Material - Physical Exercise on Aerobic Capacity in Women With Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Supplemental Material for Physical Exercise on Aerobic Capacity in Women With Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis by María F. Chávez-Díaz, Briseidy Ortiz-Rodríguez, Lidia G. De León, Ramón Candia-Lujan, and Claudia E. Carrasco-Legleu in American Journal of Lifestyle Medicine.

Footnotes

Author’s Note

The corresponding author, on behalf of all co-signatories, affirms the accuracy, transparency, and integrity of the data and information presented in the study; confirms that no relevant information has been omitted; and certifies that any disagreements among the authors have been appropriately addressed and thoroughly documented.

Author Contributions

María F. Chávez-Díaz: Idea conception, data acquisition, analysis and data interpretation. Draft writing, review and editing. Final approval of the version submitted.

Briseidy Ortiz-Rodríguez: Idea conception, analysis and data interpretation, draft review and editing. Final approval of the version submitted.

Lidia G. De León: analysis and data interpretation, draft review and editing. Final approval of the version submitted.

Claudia E. Carrasco-Legleu: analysis and data interpretation, draft review and editing. Final approval of the version submitted.

Ramón Candia-Luján: analysis and data interpretation, draft review and editing. Final approval of the version submitted.

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

ORCID iDs

María F. Chávez-Díaz

Briseidy Ortiz-Rodríguez

Lidia G. De León

Ramón Candia-Luján

Claudia E. Carrasco-Legleu

Supplemental Material

Supplemental material for this article is available online.

References

Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group . Revised 2003 consensus on diagnostic criteria and long-term health risks related to polycystic ovary syndrome. Fertil Steril. 2004;81(1):19-25. doi:10.1016/j.fertnstert.2003.10.004

Salari

Nankali

Ghanbari

, et al. Global prevalence of polycystic ovary syndrome in women worldwide: a comprehensive systematic review and meta-analysis. Arch Gynecol Obstet. 2024;310(3):1303-1314. doi:10.1007/s00404-024-07607-x

National Institute of Health . Evidence-Based Methodology Workshop on Polycystic Ovary Syndrome. Bethesda, Maryland: National Institute of Health, Office of Disease Prevention and the Eunice Kennedy Shriver National Institute of Child Health and Human Development; 2012.

Ortiz-Flores

Luque-Ramiréz

Escobar-Morales

. Síndrome de ovario poliquístico en la mujer adulta. Med Clin. 2019;152(11):450-457. doi:10.1016/j.medcli.2018.11.019

Rosenfield

Ehrmann

. The pathogenesis of polycystic ovary syndrome (PCOS): the hypothesis of PCOS as functional ovarian hyperandrogenism revisited. Endocr Rev. 2016;37(5):467-520. doi:10.1210/er.2015-1104

Stańczak

Grywalska

Dudzińska

. The latest reports and treatment methods on polycystic ovary syndrome. Ann Med. 2024;56(1):2357737. doi:10.1080/07853890.2024.2357737

García-Sáenz

Lobaton-Ginsberg

Ramiréz-Rentería

, et al. Hirsutism and polycystic ovarian morphology are the Most frequent components of polycystic ovary syndrome in women with type 1 diabetes. Arch Med Res. 2023;54(7):102895. doi:10.1016/j.arcmed.2023.102895

Escobar-Morales

. Polycystic ovary syndrome: definition, aetiology, diagnosis and treatment. Nat Rev Endocrinol. 2018;14(5):270-284. doi:10.1038/nrendo.2018.24

Charifson

Trumble

. Evolutionary origins of polycystic ovary syndrome: an environmental mismatch disorder. Evol Med Public Health. 2019;2019(1):50-63. doi:10.1093/emph/eoz011

10.

Bushell

Crespi

. The evolutionary basis of elevated testosterone in women with polycystic ovary syndrome: an overview of systematic reviews of the evidence. Front Reprod Health. 2024;6:1475132. doi:10.3389/frph.2024.1475132

11.

Armanini

Boscaro

Bordin

Sabbadin

. Controversies in the pathogenesis, diagnosis and treatment of PCOS: focus on insulin resistance, inflammation, and hyperandrogenism. Int J Mol Sci. 2022;23(8):4110. doi:10.3390/ijms23084110

12.

Azziz

Carmina

Dunaif

, et al. Polycystic ovary syndrome. Nat Rev Dis Primers. 2016;11(2):16057. doi:10.1038/nrdp.2016.57

13.

Baioccato

Quinto

Rovai

, et al.

Do androgenic pattern, insulin state and growth hormone affect cardiorespiratory fitness and strength in young women with PCOS?

Biomedicines. 2022;10(9):2176. doi:10.3390/biomedicines10092176

14.

Bacchi

Negri

Di Sarra

, et al. Serum testosterone predicts cardiorespiratory fitness impairment in normal-weight women with polycystic ovary syndrome. Clin Endocrinol. 2015;83:895-901. doi:10.1111/cen.12855

15.

Orio

Giallauria

Palomba

, et al. Cardiopulmonary impairment in young women with polycystic ovary syndrome. J Clin Endocrinol Metab. 2006;91(8):2967-2971. doi:10.1210/jc.2006-0216

16.

Valensi

Nguyen

Idriss

, et al. Influence of parasympathetic dysfunction and hyperinsulinemia on the hemodynamic response to an isometric exercise in non-insulin-dependent diabetic patients. Metabolism. 1998;14(8):934-939. doi:10.1016/s0026-0495(98)90347-x

17.

Giallauria

Palomba

De Sio

, et al. Inflammatory markers and visceral fat are inversely associated with maximal oxygen consumption in women with polycystic ovary syndrome (PCOS). Clin Endocrinol. 2009;70(3):394-400. doi:10.1111/j.1365-2265.2008.03336.x

18.

Lyerly

Sui

Lavie

Church

Hand

Blair

. The association between cardiorespiratory fitness and risk of all-cause mortality among women with impaired fasting glucose or undiagnosed diabetes mellitus. Mayo Clin Proc. 2009;84(9):780-786. doi:10.4065/84.9.780

19.

Teede

Tay

Laven

, et al. International PCOS network. Recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome. Eur J Endocrinol. 2023;189(2):G43-G64. doi:10.1093/ejendo/lvad096

20.

Harrison

Lombard

Moran

Teede

. Exercise therapy in polycystic ovary syndrome: a systematic review. Hum Reprod Update. 2010;17(2):171-183. doi:10.1093/humupd/dmq045

21.

Qiao

. Association of insulin resistance and elevated androgen levels with polycystic ovarian syndrome (PCOS): a review of literature. J Healthc Eng. 2022;2022:9240569. doi:10.1155/2022/9240569

22.

Patten

Boyle

Moholdt

, et al. Exercise interventions in polycystic ovary syndrome: a systematic review and meta-anallysis. Front Physiol. 2020;11:606. doi:10.3389/fphys.2020.00606

23.

Regensteiner

. Type 2 diabetes mellitus and cardiovascular exercise performance. Rev Endocr Metab Disord. 2004;5:269-276. doi:10.1023/B:REMD.00000324161.13070.01

24.

Greenwood

Noel

Kao

, et al. Vigorous exercise is associated with superior metabolic profiles in polycystic ovary syndrome independent of total exercise expenditure. Fertil Steril. 2016;105(2):486-493. doi:10.1016/j.fertnstert.2015.10.020

25.

De Matos

Vieira

Pinhal

, et al. High-intensity interval training improves markers of oxidative metabolism in skeletal muscle of individuals with obesity and insulin resistance. Front Physiol. 2018;9:1451. doi:10.3389/fphys.2018.01451

26.

Jelleyman

Yates

O'Donovan

, et al. The effects of high-intensity interval training on glucose regulation and insulin resistance: a meta-analysis. Obes Rev. 2015;16(11):942-961. doi:10.1111/obr.12317

27.

Liberati

Altman

Tetzlaff

, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration. BMJ. 2009;339:b2700. doi:10.1136/bmj.b2700

28.

Garber

Blissmer

Deschenes

, et al. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Med Sci Sports Exerc. 2011;43(7):1334-1359. doi:10.1249/MSS.0b013e318213fefb

29.

Huggins

JPT

Thomas

Chandler

, et al. Cochrane Handbook for Systematic Reviews of Interventions. 2nd ed. Chichester (UK): Wiley; 2019.

30.

RStudio Team . RStudio: integrated development environment for R. 2023.

31.

Caldas Costa

DE Sá

JCF

Stepto

, et al. Aerobic training improves quality of life in women with polycystic ovary syndrome. Med Sci Sports Exerc. 2018;50(7):1357-1366. doi:10.1249/MSS.0000000000001579

32.

Giallauria

Palomba

Maresca

, et al. Exercise training improves autonomic function and inflammatory pattern in women with polycystic ovary syndrome (PCOS). Clin Endocrinol. 2008;69(5):792-798. doi:10.1111/j.1365-2265.2008.03305.x

33.

Orio

Giallauria

Palomba

, et al. Metabolic and cardiopulmonary effects of detraining after a structured exercise training programme in young PCOS women. Clin Endocrinol (Oxf). 2008;68(6):976-981. doi:10.1111/j.1365-2265.2007.03117.x

34.

Vince

Kirk

Aye

Atkin

Madden

. Impaired heat shock protein 72 expression in women with polycystic ovary syndrome following a supervised exercise programme. Cell Stress Chaperones. 2020;25:73-80. doi:10.1007/s12192-019-01048-1

35.

Halama

Aye

Dargham

Kulinski

Suhre

Atkin

. Metabolomics of dynamic changes in insulin resistance before and after exercise in PCOS. Front Endocrinol. 2019;10:116. doi:10.3389/fendo.2019.00116

36.

Vigorito

Giallauria

Palomba

, et al. Beneficial effects of a three-month structured exercise training program on cardiopulmonary functional capacity in young women with polycystic ovary syndrome. J Clin Endocrinol Metab. 2007;92(4):1379-1384. doi:10.1210/jc.2006-2794

37.

Patten

Mcllvenna

Levinger

, et al. High-intensity training elicits greater improvements in cardio-metabolic and reproductive outcomes than moderate-intensity training in women with polycystic ovary syndrome: a randomized clinical trial. Hum Reprod. 2022;37(5):1018-1029. doi:10.1093/humrep/deac047

38.

Benham

Booth

Corenblum

, et al. Exercise training and reproductive outcomes in women with polycystic ovary syndrome: a pilot randomized controlled trial. Clin Endocrinol (Oxf). 2021;95(2):332-343. doi:10.1111/cen.14452

39.

Philbois

Ribeiro

Tank

Dos Reis

Gerlach

Souza

HCD

. Cardiovascular autonomic modulation differences between moderate-intensity continuous and high-intensity interval aerobic training in women with PCOS: a randomized trial. Front Endocrinol. 2022;13:1024844. doi:10.3389/fendo.2022.1024844

40.

Almenning

Rieber-Mohn

Margrethe Lundgren

Shetelig Løvvik

Krohn Garnæs

Moholdt

. Effects of high intensity interval training and strength training on metabolic, cardiovascular and hormonal outcomes inWomenwithPolycystic ovary syndrome: a pilot study. PLoS One. 2015;10(9):e0138793. doi:10.1371/journal.pone.0138793

41.

Osibogun

Ogunmoroti

Michos

. Polycystic ovary syndrome and cardiometabolic risk: opportunities for cardiovascular disease prevention. Trends Cardiovasc Med. 2020;30(7):399-404. doi:10.1016/j.tcm.2019.08.010

42.

Kodama

Saito

Tanaka

, et al. Cardiorespiratory fitness as a quantitative predictor of all-cause mortality and cardiovascular events in healthy men and women: a meta-analysis. JAMA. 2009;301(19):2024-2035. doi:10.1001/jama.2009.681

43.

Breyley-Smith

Mousa

Teede

Johnson

Sabag

. The effect of exercise on cardiometabolic risk factors in the effect of exercise on cardiometabolic risk factors in and meta-analysi. Int J Environ Res Public Health. 2022;19(3):1386. doi:10.3390/ijerph19031386

44.

Kanaley

Colberg

Corcoran

, et al. Exercise/physical activity in individuals with type 2 diabetes: a consensus statement from the American college of sports medicine. Med Sci Sports Exerc. 2022;54(2):353-368. doi:10.1249/MSS.0000000000002800

45.

Coretti

Donatello

Bianco

Cidral-Filho

. An integrative review of the effects of high-intensity interval training on the autonomic nervous system. Sports Med Health Sci. 2025;7(2):77-84. doi:10.1016/j.smhs.2024.08.002

46.

Dohlmann

Hindsø

Helge

Larsen

. High-intensity interval training changes mitochondrial respiratory capacity differently in adipose tissue and skeletal muscle. Physiol Rep. 2018;6(8):e13857. doi:10.14814/phy2.13857

47.

Donà

Bacchi

Moghetti

. Is cardiorespiratory fitness impaired in PCOS women? A review of the literature. J Endocrinol Invest. 2017;40(5):463-469. doi:10.1007/s40618-016-0599-1

48.

Thomson

Buckley

Moran

, et al. Comparison of aerobic exercise capacity and muscle strength in overweight women with and without polycystic ovary syndrome. BJOG. 2009;116(9):1242-1250. doi:10.1111/j.1471-0528.2009.02177.x

49.

Kite

Lahart

Afzal

, et al. Exercise, or exercise and diet for the management of polycystic ovary syndrome: a systematic review and meta-analysis. Syst Rev. 2019;8(1):51. doi:10.1186/s13643-019-0962-3

50.

Nybacka

Carlström

Ståhle

Nyrén

Hellström

Hirschberg

. Randomized comparison of the influence of dietary management and/or physical exercise on ovarian function and metabolic parameters in overweight women with polycystic ovary syndrome. Fertil Steril. 2011;96(6):1508-1513. doi:10.1016/j.fertnstert.2011.09.006

51.

L u

Baker

Ying

. Effects of practical models of low-volume high-intensity interval training on glycemic control and insulin resistance in adults: a systematic review and meta-analysis of randomized controlled studies. Front Endocrinol. 2025;16:1481200. doi:10.3389/fendo.2025.1481200

52.

Ryan

Schleh

Ludzki

, et al. Moderate-intensity exercise and high-intensity interval training affect insulin sensitivity similarly in obese adults. J Clin Endocrinol Metab. 2020;105(8):e2941-e2959. doi:10.1210/clinem/dgaa345

53.

Robinson

Dasari

Konopka

, et al. Enhanced protein translation underlies improved metabolic and physical adaptations to different exercise training modes in young and old humans. Cell Metab. 2017;25(3):581-592. doi:10.1016/j.cmet.2017.02.009

54.

Dalmazzo

Ponce

Delgado-Floody

Carrasco-Alarcón

Martínez-Salazar

. Efectos del ejercicio físico intervalado en la mejora del control glicémico de adultos obesos con insulinorresistencia. Nutr Hosp. 2018;36(3):578-582. doi:10.20960/nh.2075

55.

Ahmad

Mahmoud

Serry

Mohamed

Elghaffar

HAA

. Effects of low-versus high-volume high-intensity interval training on glycemic control and quality of life in obese women with type 2 diabetes: a randomized controlled trial. J Exerc Sci Fit. 2023;21(4):395-404. doi:10.1016/j.jesf.2023.08.003

56.

Mohammadi

Monazzami

Alavimilani

. Effects of eight-week high-intensity interval training on some metabolic, hormonal and cardiovascular indices in women with PCOS: a randomized controlled trail. BMC Sports Sci Med Rehabil. 2023;15(1):47. doi:10.1186/s13102-023-00653-z

57.

Ribeiro

Kogure

Lopes

, et al. Effects of continuous and intermittent aerobic physical training on hormonal and metabolic profile, and body composition in women with polycystic ovary syndrome: a randomized controlled trial. Clin Endocrinol. 2020;93(2):173-186. doi:10.1111/cen.14194

58.

Aye

Butller

Kilpatrick

, et al. Dynamic change in insulin resistance induced by free fatty acids is unchanged though insulin sensitivity improves following endurance exercise in PCOS. Front Endocrinol. 2018;9:592. doi:10.3389/fendo.2018.00592

59.

Zhang

Bao

Zhou

Zheng

. Polycystic ovary syndrome and mitochondrial dysfunction. Reprod Biol Endocrinol. 2019;17(67):67. doi:10.1186/s12958-019-0509-4

60.

Malamouli

Levinger

McAinch

Trewin

Rodgers

Moreno-Asso

. The mitochondrial profile in women with polycystic ovary syndrome: impact of exercise. J Mol Endocrinol. 2022;68(3):R11-R23. doi:10.1530/JME-21-0177

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.00 MB

0.40 MB