The effect of pelvic floor muscle training on sexual function, depressive symptoms, and pelvic floor muscle performance in women with overactive bladder: a randomized controlled

Abstract

Introduction

Pelvic floor muscle training (PFMT) improves urethral pressure, reduces detrusor muscle overactivity, and helps suppress the micturition reflex, thus contributing to symptom control. This study aimed to investigate the effects of pelvic floor muscle training on sexual function, depressive symptoms, and pelvic floor muscle performance in women with overactive bladder (OAB).

Methods

This study was conducted with 64 women (32 women: intervention group, 32 women: control group) who applied to Erzurum City Hospital Urology Polyclinic between December 1, 2021 and December 1, 2024. The study data were collected by Personal Information Form, Urinary Diary Follow-up Form, Overactive Bladder Questionnaire (OAB-V8), Female Sexual Function Index (FSFI), Sexual Quality of Life Scale-Woman (SQoL-F), Epidemiological Research Center Depression Scale (CES-D), Pelvic Floor Muscle Training Intervention Follow-up Form, Digital palpation (pelvic floor muscle strength measurement). In the intervention group, PFMT was performed for 6 weeks with biofeedback with the Simplex Device in accordance with the given PFMT intervention procedure.

Results

Following the 6-week intervention, women receiving PFMT demonstrated significantly lower OAB symptom severity and depressive symptoms and significantly higher sexual function, sexual quality of life, pelvic floor muscle strength, contraction strength, and MVC% than women in the control group. They also showed significantly higher sexual quality of life, pelvic floor muscle contraction strength, maximum voluntary contraction (MVC%), and pelvic floor muscle strength (all p < 0.05). No significant between-group difference was observed in pelvic floor muscle relaxation values (p > 0.05).

Conclusion

Women receiving PFMT demonstrated lower OAB symptom severity and depressive symptom scores and higher sexual quality of life and pelvic floor muscle performance measures. Because female sexual function (FSFI) was the predefined primary outcome, findings related to secondary outcomes should be interpreted as exploratory.

Trial registration

Trial Registration Number: NCT07030608 (ClinicalTrials.gov, May 30, 2025; retrospectively registered).

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12905-026-04723-5.

Introduction

Overactive bladder syndrome (OAB) is defined by the International Continence Society Research Society (ICI-RS) in 2014 as “a condition characterized by urinary urgency, with or without urge incontinence, often accompanied by frequency and nocturia, in the absence of proven infection or other obvious pathology” [1]. Various treatment methods are available for the management of OAB, with behavioral therapies playing a particularly significant role in clinical practice [2].

The foundation of behavioral therapy is to foster patient understanding of normal and abnormal bladder function and to teach strategies for preventing or managing OAB and urge urinary incontinence (UUI) [3]. Behavioral therapy typically includes lifestyle modifications, bladder training, and pelvic floor muscle training (PFMT), and clinical guidelines support its use as a first-line treatment due to its safety and efficacy [4, 5]. A systematic review has shown that behavioral interventions can be more effective than anticholinergic medications in managing urgency urinary incontinence [6]. Among behavioral therapies, PFMT has been shown to have a positive effect on the pelvic floor and is increasingly utilized in the treatment of OAB [7].

Using PFMT to treat symptoms in women with OAB has been found to enhance voluntary pelvic floor contractions and reduce symptom severity. PFMT improves urethral pressure, reduces detrusor muscle overactivity, and helps suppress the micturition reflex, thus contributing to symptom control [8, 9]. As a result of these mechanisms, patients are better able to delay urination, reducing episodes of incontinence and improving quality of life [10]. Depression is one of the most common psychological comorbidities associated with OAB [11]. Persistent urgency, nocturia, and urinary incontinence adversely affect social participation, self-esteem, sleep quality, and emotional well-being [12, 13]. Therefore, assessment of depressive symptoms provides important information regarding the broader psychosocial benefits of pelvic floor muscle training beyond urinary symptom improvement.

Although the effects of PFMT on urinary symptoms have been widely studied in the literature, its impact on sexual function, particularly in women diagnosed with OAB, has been investigated in only a limited number of studies [14, 15]. Therefore, this study was designed to evaluate the effect of PFMT on sexual life in women with OAB. As one of the few studies addressing this intersection, it aims to contribute to the literature and offer insights for developing multidisciplinary and clinically applicable interventions. With its experimental design and structured training program, the study also aims to guide future clinical practices and enrich the scientific understanding of women’s health within nursing and allied health disciplines. This study aimed to investigate the effects of pelvic floor muscle training on sexual function, depressive symptoms, and pelvic floor muscle performance in women with OAB.

Materials and methods

Study design

This research was conducted as a randomized controlled experimental study. The study was carried out at the Urology Outpatient Clinic of Erzurum City Hospital between December 1, 2021, and December 18, 2024.

Study population and sample size

The population of this study consisted of women diagnosed with Overactive Bladder (OAB) at the Urology Outpatient Clinic of Erzurum City Hospital between December 1, 2021, and December 1, 2024. The diagnosis of overactive bladder was established by an experienced urologist according to the International Continence Society (ICS) definition and current AUA/SUFU clinical practice guidelines. All women underwent a comprehensive urological evaluation including medical history, physical examination, urinalysis to exclude urinary tract infection, bladder diary assessment, and urodynamic examination when clinically indicated. Women diagnosed with idiopathic OAB by the treating urologist were referred to the research team for eligibility assessment and recruitment. A priori power analysis was conducted to determine the sample size of the study. The power analysis was performed using G*Power 3.1 software. Cohen’s standard effect sizes were used as a reference method in the analysis [16]. According to the power analysis, a minimum of 64 women (32 in the intervention group and 32 in the control group) were required to achieve 80% power at a 0.05 level of significance with a 95% confidence interval. Based on these data, a total of 64 women with OAB who met the inclusion criteria and agreed to participate in the study were included in the sample—32 assigned to the intervention group and 32 to the control group. The allocation of participants into the intervention and control groups was determined through randomization [16].

Inclusion criteria

• Women aged 18–70 years,

• Ability to speak and understand Turkish,

• Literate,

• Diagnosed with overactive bladder,

• Diagnosis confirmed by a urologist,

• Receiving medication for OAB,

• Voluntary participation in the study.

To minimize potential confounding effects, participants continued the same pharmacological treatment throughout the study period without dose modification. Medication class, dosage, and treatment duration were recorded at baseline and were comparable between the intervention and control groups. No participant initiated a new OAB medication during follow-up. Baseline pharmacological characteristics, including medication classes, dosages, and treatment duration, are presented in Supplementary Table S1.

Exclusion criteria

• Cognitive or psychiatric disorders that impair communication.

• Presence of neurological diseases.

• Neuropathy due to diabetes mellitus.

• Pelvic organ prolapse stage 2 or higher.

• History of anti-incontinence surgery.

• Pregnancy.

• Previously participated in supervised pelvic floor muscle rehabilitation programs.

Randomization and blinding

The study was conducted at Erzurum City Hospital. Women diagnosed with OAB who met the eligibility criteria were randomly assigned to either the intervention group or the control group. Randomization was performed using the web-based randomization software Randomizer.org (https://www.randomizer.org). A simple randomization method with a 1:1 allocation ratio was used. Prior to participant enrollment, the principal researcher generated the random allocation sequence using the online randomization program. Eligible women who attended the urology outpatient clinic and were diagnosed with OAB by a physician based on urodynamic evaluation were enrolled consecutively and assigned to groups according to the pre-generated randomization sequence. This procedure ensured equal and random allocation of participants to the intervention and control groups. Due to the nature of the intervention, allocation concealment was not implemented, and the study was conducted as an open-label randomized controlled trial. The study process was reported in accordance with the Consolidated Standards of Reporting Trials (CONSORT) 2025 guidelines, and the participant flow diagram is presented in Fig. 1 [17].

Fig. 1.

CONSORT 2025 Flow Diagram

Data collection tools

The data collection tools used in the study included the Personal Information Form, 4-Day Voiding Diary, Overactive Bladder Questionnaire (OAB-V8), Female Sexual Function Index (FSFI), Sexual Quality of Life Scale-Female (SQoL-F), and the Center for Epidemiologic Studies Depression Scale (CES-D). Additionally, a Pelvic Floor Muscle Training Adherence Tracking Form was used. All scales had established validity and reliability in Turkish. The pelvic floor muscle strength was evaluated using both digital palpation (Modified Oxford Scale) and electromyographic (EMG) measurements via the Simplex device.

Personal Information form

The researcher developed this form to determine the demographic characteristics, obstetric-gynecological and systemic health conditions, as well as specific features related to OAB in women [14, 15].

Voiding diary (4-Day)

This diary was used to evaluate participants’ fluid intake (type and amount), urgency, urinary incontinence, and activities during episodes of urgency or incontinence.

Overactive bladder questionnaire (OAB-V8)

The OAB-V8 is a validated screening tool used to assess OAB symptoms such as urinary frequency, urgency, nocturia, and urgency urinary incontinence. It consists of 8 items scored on a scale from 0 (not at all) to 5 (a very great deal), with a total score ranging from 0 to 40. A cut-off score of 11 was determined to indicate the presence of OAB symptoms. The internal consistency of the scale has been reported as Cronbach’s alpha = 0.92 [18]. In the current study, Cronbach’s alpha was 0.74 before the intervention and 0.99 after the intervention.

Female sexual function index (FSFI)

Developed by Rosen et al. (2000) in the United States to comprehensively assess female sexual function, the FSFI was validated for Turkish use by Aygin and Aslan in 2005 [19, 20]. The scale includes 19 items and six subscales: desire, arousal, lubrication, orgasm, satisfaction, and pain. The total FSFI score ranges from 2 to 36, with lower scores indicating poorer sexual function. The clinical cut-off score is 26.55, below which sexual dysfunction is assumed. The Turkish version has demonstrated high internal consistency with a Cronbach’s alpha of 0.98 [20]. In the current study, Cronbach’s alpha was 0.92 before the intervention and 0.87 after the intervention.

Sexual quality of life scale-female (SQoL-F)

The SQoL-F was developed by Symonds et al. in 2005 and adapted into Turkish by Tuğut and Gölbaşı in 2010. It consists of 18 items scored on a 6-point Likert scale [21]. The raw score ranges from 18 to 108 and is standardized to a 0–100 scale. Higher scores indicate better sexual quality of life. The internal consistency of the scale was reported as Cronbach’s alpha = 0.83, with item-total correlations ranging from 0.32 to 0.67 [21]. In the current study, Cronbach’s alpha was 0.95 before the intervention and 0.97 after the intervention.

Sexual function and sexual quality of life represent related but distinct constructs. FSFI evaluates physiological domains of sexual response, whereas SQoL-F assesses the emotional, interpersonal, and psychosocial impact of sexual health. Therefore, both instruments were used to provide a comprehensive evaluation.

Center for epidemiologic studies depression scale (CES-D)

The CES-D is a 20-item scale developed by Radloff (1977) to assess depressive symptoms in the general population and specific groups [22]. Each item is scored from 0 to 3, yielding a total score between 0 and 60. A score of 16 or higher suggests a risk for depression. The scale consists of four subdimensions: depressive affect, positive affect, somatic symptoms, and interpersonal relations. The Turkish adaptation demonstrated a general Cronbach’s alpha of 0.85, with subscale alphas ranging from 0.60 to 0.82, indicating acceptable reliability [23]. CES-D was included to evaluate changes in psychological well-being associated with improvement in OAB symptoms rather than to diagnose clinical depression.

Pelvic floor muscle training adherence tracking form

Participants with OAB were instructed to complete this form daily for 6 weeks, indicating their adherence to morning, afternoon, and evening exercises using a scale: 0 = not performed, 1 = occasionally performed, 2 = regularly performed. Adherence was evaluated based on the completed Pelvic Floor Muscle Training Adherence Tracking Forms. Participants were considered highly adherent if they completed at least 90% of the prescribed exercise sessions during the 6-week intervention period. Exercise adherence was high throughout the intervention period. All participants in the intervention group completed the Pelvic Floor Muscle Training Adherence Tracking Form. Overall, 30 of the 32 participants (93.8%) completed at least 90% of the prescribed exercise sessions, indicating excellent adherence to the intervention protocol.

Digital palpation

Pelvic floor muscle strength and endurance (maximum contraction duration) were subjectively assessed during vaginal examination using digital palpation. The Modified Oxford Grading Scale was used for classification [24].

Simplex device

The Simplex is a single-channel electromyography (EMG) device developed for the evaluation and biofeedback training of pelvic floor muscles, including game-assisted modes (see Fig. 2). The device accurately measures muscle activity in the range of 0.2 to 2000 microvolts (µV). Three self-adhesive circular electrodes (30 mm in diameter) are used—two placed on either side of the perineum, and one reference electrode placed over the iliac crest. The reference electrode is essential for valid data collection.

Fig. 2.

Simplex device

Each session consisted of five repetitions of a 6-second contraction followed by a 6-second relaxation period. Six-second sustained contractions followed by equal relaxation were selected because this duration is based on published PFMT recommendations for improving slow-twitch muscle endurance while minimizing fatigue [25, 26]. The protocol was developed according to the manufacturer’s instructions for the NeuroTrac Simplex device and based on evidence supporting sustained pelvic floor muscle contractions for improving muscle strength and neuromuscular control, consistent with current literature for pelvic floor muscle training in women with overactive bladder [25, 26]. During the first training session, all participants in the intervention group received individualized instruction using the Simplex biofeedback device under researcher supervision. Thereafter, participants performed the prescribed pelvic floor muscle training at home without the device. The Simplex device was used once weekly during outpatient follow-up visits to evaluate muscle activity, reinforce correct contraction technique, provide biofeedback, and monitor adherence.

Data collection

The study consisted of four implementation phases, and the flowchart of the study is presented in Fig. 3. No intervention-related adverse events were observed during the study period.

Fig. 3.

Work flow chart

Intervention

Women in the intervention group performed PFMT for 6 weeks using the Simplex biofeedback device, following a structured PFMT protocol. The control group received no intervention or training. The PFMT program is outlined in Table 1. Exercise intensity was increased progressively throughout the intervention period to facilitate neuromuscular adaptation and minimize excessive muscle fatigue. Pelvic floor muscle training was provided individually by the principal investigator, who is a women’s health nurse with formal training in pelvic floor rehabilitation and biofeedback-assisted pelvic floor muscle training. Weekly follow-up sessions were conducted by the same investigator to monitor adherence, correct exercise technique, and reinforce participant motivation. No participant reported muscle fatigue, pain, or exercise-related adverse events despite the progressive increase in exercise volume.

Table 1.

PFMT implementation program

Weeks 1: The pelvic floor muscles are contracted for 6 s, followed by 6 s of relaxation. This cycle is repeated 25 times. The exercise is performed 3 times per day (a total of 75 contractions daily).

Weeks 2: The pelvic floor muscles are contracted for 6 s, followed by 6 s of relaxation. This cycle is repeated 50 times. The exercise is performed 3 times per day (a total of 150 contractions daily).

Weeks 3: The pelvic floor muscles are contracted for 6 s, followed by 6 s of relaxation. This cycle is repeated 75 times. The exercise is performed 3 times per day (a total of 225 contractions daily).

Weeks 4 to 5: The pelvic floor muscles are contracted for 6 s, followed by 6 s of relaxation. This sequence is repeated 100 times. The exercise is performed 3 times per day (a total of 300 contractions daily).

Weeks 6: The pelvic floor muscle is contracted for 6 s, followed by 6 s of relaxation. This cycle is repeated 50 times. The exercise is performed 3 times per day (a total of 150 contractions daily). Alternatively: The pelvic floor muscle is contracted for 6 s, followed by 6 s of relaxation. This cycle is repeated 75 times. The exercise is performed 2 times per day (a total of 150 contractions daily).

Outcome measures

Primary outcome

The primary outcome was female sexual function measured using the FSFI.

Secondary outcomes

Secondary outcomes included SQoL-F, OAB-V8, CES-D, pelvic floor muscle strength assessed by digital palpation, contraction strength, relaxation strength, maximum voluntary contraction (MVC%), and bladder diary variables.

Ethical considerations

Ethical approval was obtained from the Non-Interventional Clinical Research Ethics Committee of Istanbul Biruni University (Decision No: 2021/60 − 11, Date: 22.10.2021). Institutional permission was granted by Erzurum City Hospital. The study adhered to the Declaration of Helsinki principles. Written informed consent was obtained from all participants. All data were anonymized, and participants were informed that they could withdraw from the study at any stage. Necessary permissions for the use of the scales were obtained from the original authors. The research was accepted as a PhD thesis in Istanbul Biruni University Graduate Education Institute, Department of Obstetrics and Gynecology Nursing in 2025.

Statistical analysis

Data were analyzed using SPSS for Windows version 22. Descriptive statistics (mean, standard deviation, frequency, percentage) and inferential analyses were conducted. Normality was assessed using skewness and kurtosis values (± 2 threshold). For normally distributed variables, independent and paired t-tests were used. For non-normally distributed variables, Mann–Whitney U, Wilcoxon signed-rank, chi-square, and McNemar tests were applied. Effect sizes were calculated using Cohen’s d and interpreted according to Cohen’s criteria (0.20 = small, 0.50 = medium, 0.80 = large). The unusually large effect sizes observed for several outcomes reflect the substantial magnitude of change produced by the intervention rather than computational error. Because this was an exploratory randomized controlled trial evaluating several predefined secondary outcomes, adjustments for multiple comparisons were not applied. Because baseline MVC (%) values differed significantly between groups, an additional ANCOVA was conducted using post-intervention MVC (%) values as the dependent variable and baseline MVC (%) as a covariate. Instead, primary and secondary outcomes were predefined before analysis, and interpretation focused on consistency across related outcome measures rather than isolated p-values.

Results

The demographic, obstetric-gynecological, and systemic health characteristics of the women are presented in Table 2. The mean age of participants in the intervention group was 44.16 ± 9.25 years, with a mean parity of 2.34 ± 1.58. Of these women, 93.8% were married, 43.8% had completed primary education, 78.1% lived in nuclear families, 71.9% were housewives, and 84.4% had children. Similarly, the control group had a mean age of 45.38 ± 10.75 years and a mean parity of 2.69 ± 1.80. In this group, 93.8% were married, 59.4% were primary school graduates, 87.5% lived in nuclear families, 78.1% were housewives, and 84.4% had children. There were no statistically significant differences between the intervention and control groups in any demographic characteristic (p > 0.05).

Table 2.

Demographic, obstetric-gynecologic and systemic disease-related characteristics of women

Variables				Intervention Group		Control Group		Materiality
				n	%	n	%
Marital Status	Married			30	93.8	30	93.8	p = 1.000*
	Single			2	6.3	2	6.3
Education Status	Primary School			14	43.8	19	59.4	x2=2.682 p = 0.612
	Middle School			5	15.6	3	9.4
	High School			6	18.8	5	15.6
	University			6	18.8	3	9.4
	Postgraduate			1	3.1	2	6.3
Family type	Nucleus			25	78.1	28	87.5	x2=0.988 p = 0.320
	Expanded			7	21.9	4	12.5
Work Status	Not working			23	71.9	25	78.1	x2=0.333 p = 0.564
	Working			9	28.1	7	21.9
Income Status	Income is less than expenses			6	18.8	1	3.1	p = 0.104*
	Income is equal to expenses			26	81.3	31	96.9
Smoking	Not drinking			24	75.0	25	78.1	x2=0.087 p = 0.768
	Drinking			8	25.0	7	21.9
Using Alcohol	Not using			32	100	32	100	-
Having Children	No			5	15.6	5	15.6	x2=0.000 p = 1.000
	Yes			27	84.4	27	84.4
Presence of Episiotomy	No			24	75.0	24	75.0	x2=0.000 p = 1.000
	Yes			8	25.0	8	25.0
Having Episiotomy-Related Complications	No			27	84.4	30	93.8	p = 0.426*
	Yes			5	15.6	2	6.3
Complication Experienced	Hematoma			4	12.5	1	3.1	x2=1.958 p = 0.376
	Infection			1	3.1	1	3.1
	No			27	84.4	30	93.8

Continuous Variables	Intervention Group			Control Group			Materiality
	n	Mean	SD	n	Mean	SD
Age	32	44.16	9.25	32	45.38	10.75	t=-0.486, p = 0.629
BMI	32	31.17	5.83	32	29.65	5.58	t = 1.066, p = 0.290
Duration of marriage	32	18.97	9.76	32	22.00	12.56	t=-1.078, p = 0.285
Number of children	32	2.34	1.58	32	2.69	1.80	U = 442.500, p = 0.334
Gravida	32	3.00	2.21	32	3.59	2.61	t=-0.981, p = 0.331
Parity	32	2.34	1.58	32	2.69	1.80	U = 442.500, p = 0.334
Number of abortions	32	0.34	0.94	32	0.56	0.88	U = 422.500, p = 0.113
Number of curettages	32	0.28	0.58	32	0.34	1.12	U = 469.000, p = 0.379
Number of vaginal births	32	1.97	1.69	32	2.09	1.69	t=-0.295, p = 0.769
Number of caesarean sections	32	0.41	0.87	32	0.50	0.84	t = 469.500, p = 0.462

Table 3 presents the group and within-group comparisons of urinary diary parameters before and after the intervention. At baseline, the intervention group had a mean daily fluid intake of 1276.56 ± 561.99 ml, mean daily voiding frequency of 8.16 ± 2.40, mean frequency of urgency episodes 3.09 ± 1.63, and mean daily incontinence episodes 0.63 ± 0.25. The control group showed similar values: 1255.31 ± 544.23 ml for fluid intake, 8.28 ± 2.45 for voiding, 2.75 ± 1.80 for urgency, and 0.63 ± 0.55 for incontinence. No statistically significant changes were observed in daily fluid intake in either group throughout the study (p > 0.05). Daily fluid intake remained stable throughout the study and did not differ significantly either within or between groups (p > 0.05). In contrast, women in the intervention group demonstrated significant reductions in daily voiding frequency, urgency episodes, and urinary incontinence compared with the control group (all p < 0.05).

Table 3.

Comparison of the bladder diary of women’s initial and post-intervention assessment between and within groups

Variable	Measurement Time	Intervention Group (n = 32)		Control Group (n = 32)		Test Value	p
		Mean	SD	Mean	SD
Daily Liquid Consumption Amount (ml)	First evaluation	1276.56	561.99	1255.31	544.23	t = 0.154	0.878
	Evaluation after intervention	1221.88	528.86	1242.19	520.37	t=-0.155	0.877
Test Value / p		Z = 4.837	0.000	Z = 1.553	0.131	-	-
Cohen d		0.100206		0.031703		-
Number of Daily Toilet Visits	First evaluation	8.16	2.40	8.28	2.45	t = 0.206	0.837
	Evaluation after intervention	4.06	1.52	6.69	1.42	t = 7.122	0.000
Test Value / p		Z = 8.380	0.000	Z = 5.622	0.000	-	-
Cohen d		2.041039		0.794063		-
Number of Daily Urge to Urinate	First evaluation	3.09	1.63	2.75	1.80	t=-0.801	0.426
	Evaluation after intervention	0.63	0.55	2.94	2.09	t = 6.041	0.000
Test Value / p		Z = 8.806	0.000	Z=-1.646	0.110	-	-
Cohen d		2.022313		0.097416		-
Daily Urinary Incontinence Number	First evaluation	0.63	0.25	0.63	0.55	t = 0.000	1.000
	Evaluation after intervention	0.25	0.44	0.63	0.55	t = 3.000	0.004
Test Value / p		Z = 3.215	0.003	Z = 0.000	1.000	-	-
Cohen d		1.061925		-		-

The unusually large effect sizes observed for several outcomes reflect the substantial magnitude of change produced by the intervention rather than computational error

Effect sizes were calculated using Cohen’s d and interpreted according to Cohen’s criteria (0.20 = small, 0.50 = medium, 0.80 = large)

Table 4 shows the between-group and within-group comparisons of OAB-V8, FSFI, SQoL-F, CES-D scores, contraction strength, relaxation strength, maximum voluntary contraction (MVC %) values, and pelvic floor muscle strength. Baseline values were comparable between the intervention and control groups for all outcome variables except MVC%, which was significantly higher in the control group (p < 0.05). Following the intervention, women receiving PFMT demonstrated significantly lower OAB symptom severity, depressive symptoms, urinary frequency, urgency episodes, and urinary incontinence than controls. They also showed significantly greater sexual quality of life, pelvic floor muscle contraction strength, MVC%, and pelvic floor muscle strength. No statistically significant between-group difference was observed for relaxation strength.

Table 4.

Comparison of OAB-V8, FSFI, SQoL-F, CES-D, pelvic floor muscle performance, and adjusted MVC values between and within groups

Variable	Measurement time	Intervention group (n = 32) Mean ± SD	Control group (n = 32) Mean ± SD	Test statistic	p value
OAB-V8	Baseline	35.72 ± 3.48	35.03 ± 3.22	t = 0.820	0.415
	Post-intervention	2.84 ± 4.00	35.72 ± 2.77	t=-38.201	< 0.001
	Within-group comparison	t = 36.851 / p < 0.001	t=-1.159 / p = 0.255	—	—
	Cohen’s d (within-group)	6.514	-0.205	—	—
FSFI Total	Baseline	20.71 ± 6.40	20.76 ± 7.34	t=-0.025	0.980
	Post-intervention	18.06 ± 3.58	20.68 ± 4.81	t=-2.476	0.016
	Within-group comparison	t = 2.654 / p = 0.012	t = 0.099 / p = 0.922	—	—
	Cohen’s d (within-group)	0.469	0.017	—	—
SQoL-F	Baseline	56.42 ± 28.26	58.61 ± 29.92	t=-0.301	0.765
	Post-intervention	81.70 ± 14.34	36.60 ± 27.14	t = 8.313	< 0.001
	Within-group comparison	t=-5.080 / p < 0.001	t = 3.876 / p = 0.001	—	—
	Cohen’s d (within-group)	-0.898	0.685	—	—
CES-D	Baseline	28.50 ± 12.63	28.97 ± 12.36	t=-0.150	0.881
	Post-intervention	10.25 ± 11.56	37.78 ± 9.25	t=-10.520	< 0.001
	Within-group comparison	t = 7.066 / p < 0.001	t=-3.506 / p = 0.001	—	—
	Cohen’s d (within-group)	1.249	-0.620	—	—
Muscle strength	Baseline	0.75 ± 0.80	0.47 ± 0.67	t = 1.520	0.134
	Post-intervention	4.38 ± 0.71	0.41 ± 0.56	t = 24.891	< 0.001
	Within-group comparison	t=-17.311 / p < 0.001	t = 0.571 / p = 0.752	—	—
	Cohen’s d (within-group)	-3.060	0.101	—	—
Contraction strength (Work average, µV)	Baseline	6.65 ± 2.41	6.06 ± 3.11	t = 0.858	0.394
	Post-intervention	28.41 ± 10.77	5.60 ± 2.34	t = 11.712	0.001
	Within-group comparison	t=-10.680 / p < 0.001	t = 0.935 / p = 0.357	—	—
	Cohen’s d (within-group)	-1.888	0.165	—	—
Relaxation strength (Rest average, µV)	Baseline	2.93 ± 1.25	3.13 ± 2.15	t=-0.454	0.651
	Post-intervention	2.39 ± 0.63	2.54 ± 1.46	t=-0.513	0.610
	Within-group comparison	t = 2.582 / p = 0.015	t = 1.390 / p = 0.175	—	—
	Cohen’s d (within-group)	0.456	0.246	—	—

Variable	Adjusted mean (Intervention)	Adjusted mean (Control)	F	p value	Partial η²
MVC (%)†	56.04 (53.22–58.87)	36.66 (33.84–39.49)	73.510	< 0.001	0.547

Cohen’s d values represent within-group effect sizes calculated from pre- to post-intervention changes

Abbreviations: OAB-V8 Overactive Bladder Questionnaire, FSFI Female Sexual Function Index, SQoL-F Sexual Quality of Life Scale-Female, CES-D Center for Epidemiologic Studies Depression Scale, MVC maximum voluntary contraction

† Because baseline MVC (%) values differed significantly between groups, post-intervention MVC values were additionally analyzed using analysis of covariance (ANCOVA), adjusting for baseline MVC values

Because baseline MVC (%) values differed significantly between groups, an additional analysis of covariance (ANCOVA) was performed using post-intervention MVC (%) values as the dependent variable and baseline MVC (%) as a covariate. The assumption of homogeneity of variances was satisfied (Levene’s test: F = 0.487, p = 0.488). After adjustment for baseline MVC values, the intervention effect remained statistically significant (F(1,61) = 73.510, p < 0.001, partial η²=0.547). The adjusted mean MVC values were 56.04 (95% CI: 53.22–58.87) in the intervention group and 36.66 (95% CI: 33.84–39.49) in the control group.

Discussion

This randomized controlled study showed that women receiving PFMT had better outcomes in overactive bladder symptoms, sexual quality of life, depressive symptoms, and pelvic floor muscle performance. However, because female sexual function (FSFI) was the predefined primary outcome, findings related to secondary outcomes should be interpreted cautiously. In addition, urinary frequency, urgency episodes, and urinary incontinence decreased significantly following the intervention. These findings suggest that structured pelvic floor muscle training may be a promising first-line conservative intervention for women with OAB.

Post-intervention female sexual function scores were higher in the intervention group compared to the control group. Atlıhan et al. (2025) investigated the effects of OAB on sexual function in 74 women, reporting mean FSFI subdomain scores as follows: desire 3.3 ± 0.4, arousal 3.2 ± 0.3, lubrication 3.2 ± 0.3, orgasm 3.1 ± 0.2, satisfaction 3.3 ± 0.3, pain 3.1 ± 0.3, and total FSFI score of 19.2 ± 1.8, indicating a decline in sexual function [27]. Several studies consistently reported impaired sexual function in women with OAB, supporting the negative impact of urinary symptoms on female sexuality. Our findings extend this evidence by showing an association between structured PFMT and improved sexual function [24, 28–30]. A recent systematic review and meta-analysis by Jorge et al. (2024) further supports our findings by reporting an association between PFMT and better overall female sexual function, particularly arousal, orgasm, satisfaction, and pain domains [31]. These findings suggest that PFMT may be associated with better sexual function in women with OAB. The improvement in sexual function may be explained through several physiological and psychosocial mechanisms. Pelvic floor muscle training increases pelvic muscle strength, enhances vaginal support, improves pelvic blood circulation, and facilitates neuromuscular coordination [32]. Furthermore, reduction of urgency and urinary leakage during sexual activity may decrease anxiety, improve self-confidence, and enhance overall sexual satisfaction.

Post-intervention sexual quality of life was higher in the intervention group compared to the control group. Although total FSFI scores showed only modest improvement, sexual quality of life improved substantially in intervention group. This discrepancy may reflect that PFMT primarily enhanced women’s confidence, body image, emotional well-being, and satisfaction with their sexual relationships before producing marked physiological improvements in sexual function. Because sexual quality of life encompasses broader psychosocial dimensions than sexual function alone, improvements in SQoL-F may occur even when physiological sexual response changes remain limited. Dunya et al. (2025) reported that women with both diabetes and OAB had lower sexual quality of life scores compared to healthy women and those with OAB alone [33]. Sondka-Migdalska et al. (2024) found that OAB patients treated with botulinum toxin had a baseline mean sexual quality of life score (SQoL-F) of 40.69 ± 27.79, indicating moderate-low levels [34]. Güleryüz et al. (2023) reported a mean SQoL-F score of 66.83 ± 21.06 in women with urinary incontinence, indicating moderate quality of life [35]. García and Muñoz (2015) reported that 19.9% of 458 women with OAB indicated that OAB symptoms negatively impacted their sexual life [36]. These results are consistent with the literature, suggesting that OAB negatively affects sexual quality of life, but various non-pharmacological treatments may improve it [37].

Pelvic floor muscle training substantially reduced urinary frequency, urgency, and urinary incontinence. These improvements are consistent with the proposed physiological mechanisms of PFMT, including enhanced voluntary pelvic floor muscle contraction, inhibition of detrusor overactivity, and improved urethral support. Similar improvements have been reported in previous randomized controlled trials evaluating PFMT in women with OAB. In the study by Liu et al. (2024), which examined the effectiveness of biofeedback-supported pelvic floor muscle training combined with a short-term medication regimen in women with overactive bladder (OAB), the mean daily fluid intake, mean daily urgency episodes, and mean daily incontinence episodes in the biofeedback-only group were reported as 1536.4 ± 328.3 ml and 1657.4 ± 468.4 ml, 4.3 ± 3.5 and 2.1 ± 2.6, and 1.93 ± 3.5 and 0.4 ± 1.3 before and after the intervention, respectively [38]. Our findings are consistent with those of Celenay et al. (2022), who demonstrated that a structured PFMT program significantly improved sexual function, urinary symptoms, and pelvic floor muscle strength in women with OAB. Together, these findings suggest that PFMT may be associated with favorable urinary and sexual outcomes in this population [39]. Karaaslan et al. (2021) reported that the median daily incontinence episodes in the PFMT + CTM (connective tissue massage) group were 2.33, 0.66, and 0.0 pre-intervention, mid-follow-up, and post-intervention, respectively, while in the PFMT-only group these values were 2.33, 1.0, and 0.33 [40]. The present findings are further supported by the systematic review of Bø et al. (2020), which concluded that PFMT consistently reduces urgency urinary incontinence, urinary frequency, and OAB symptoms while improving pelvic floor muscle function across randomized trials [41]. The findings of the present study are consistent with the literature, indicating that overactive bladder positively affects the frequency of daily urination, weekly urgency, and incontinence episodes.

Post-intervention, the severity of OAB symptoms was significantly lower in the intervention group compared to the control group. The observed reduction in urinary frequency cannot be attributed to decreased fluid intake because daily fluid consumption remained stable throughout the intervention and did not differ significantly between or within groups. The reduction in urinary frequency may reflect improved bladder control associated with pelvic floor muscle training rather than behavioral fluid restriction. Celenay et al. (2023) examined the effects of pelvic-focused spinal stabilization exercises in 47 women with OAB, reporting that the intervention group’s mean OAB-V8 scores decreased from 26.83 ± 8.41 to 10.26 ± 6.23, while the control group’s scores decreased from 24.00 ± 9.38 to 16.42 ± 8.46, demonstrating a greater symptom reduction in the intervention group [42]. In another study by Toprak Celenay et al. (2022), the PFMT + KT group’s mean OAB-V8 scores decreased from 23.3 ± 8.1 to 9.4 ± 6.5, while the PFMT + ST group’s scores decreased from 26.1 ± 7.8 to 11.1 ± 6.7, confirming greater improvement in the intervention group. Moreover, the control group showed no significant change between baseline and final assessment, whereas the intervention group exhibited a substantial reduction in symptoms [39]. Other studies also demonstrate that behavioral treatments such as PFMT reduce OAB symptom severity in women [28, 42, 43]. These findings align with the literature and suggest that pelvic floor muscle training may be associated with reduced OAB symptom severity.

Post-intervention pelvic floor muscle contraction strength was higher in the intervention group compared to the control group, while relaxation strength was lower. Xu et al. (2015) studied two groups of OAB patients, one receiving PFMT (3 sets daily, 15–20 repetitions per session) and the other standard treatment (bladder training, lifestyle modifications, regulated fluid intake) [44]. At 3 months, the PFMT group showed significantly greater contraction strength than the standard treatment group. However, there is no standardized protocol for evaluating pelvic floor contraction-relaxation strength, and protocols vary based on muscle status [44]. Developing appropriate protocols to ensure compliance is recommended in the literature [26, 45]. Although hypertrophy and neural adaptations in pelvic floor muscles occur over six months, increasing PFMT intensity accelerates strength and endurance gains [41]. Our findings show that the intervention group had better contraction and relaxation strength than controls, with improved relaxation characteristics.

When comparing pre- and post-intervention values, pelvic floor muscle strength was higher in the intervention group than in the control group. Although baseline MVC (%) values differed significantly between groups, additional ANCOVA analyses adjusting for baseline MVC confirmed that the between-group difference remained statistically significant. Nevertheless, MVC-related findings should still be interpreted with caution because baseline imbalance cannot be completely eliminated. This baseline imbalance has therefore been acknowledged as a limitation when interpreting MVC-related findings. Celenay et al. (2023) reported median PFMT scores of 3.00 pre-intervention and 4.00 post-intervention in the intervention group, versus 2.00 and 2.00 in controls, with greater symptom improvement in the intervention group [42]. Toprak Celenay et al. (2022) found median PFMT scores of 3.0 pre-intervention and 4.0 post-intervention in the PFMT + KT group, and 3.0 and 4.0 in the PFMT-only group [39]. Karaaslan et al. (2021) reported median PFMT of 4.6, 6.0, and 7.8 pre-, mid-, and post-intervention in the PFMT + CTM group, and 4.5, 6.0, and 8.0 in the PFMT-only group [40]. Our findings suggest that women receiving PFMT demonstrated greater pelvic floor muscle strength and lower OAB symptom severity.

Although the total number of daily contractions appears relatively high, the exercise program followed a progressive loading principle, beginning with lower exercise volumes and gradually increasing over the intervention period. Previous pelvic floor muscle training studies have similarly recommended high-repetition exercise programs to optimize strength and endurance adaptations [46–48]. Weekly supervised follow-up visits allowed exercise technique, tolerance, and potential fatigue to be monitored. No participant reported exercise-related adverse events or discontinued the intervention because of muscle fatigue.

Although depressive symptoms may arise from multiple causes unrelated to OAB, randomization minimized systematic differences between groups and baseline CES-D scores were comparable. Post-intervention depression risk was lower in the intervention group compared to the control group. Li et al. (2025) analyzed the relationship between depression severity and OAB in a large sample of 19,543 patients, reporting a mean PHQ-9 score of 5.07 ± 5.34 in women with OAB, with depression independently associated with OAB, particularly mild to severe depression [49]. Zhang et al. (2024), using NHANES 2005–2018 data of 6,612 adults, found a significant positive association between OAB severity and depression, assessed via PHQ-9 [50]. Akkoç et al. (2023) examined women with multiple sclerosis and OAB, finding a mean HADS depression score of 9.23 ± 4.59 in the OAB group [51]. Malak (2018) reported mean depression scores measured by the Epidemiological Studies Depression Scale (EADS) of 14.12 ± 11.88 in normal BMI and 16.06 ± 11.95 in obese women with OAB [52]. These findings suggest that OAB adversely affects psychological well-being, possibly due to social isolation and impaired social functioning, leading to increased depression risk. In our study, lower OAB symptom severity was accompanied by lower depressive symptom scores.

Strengths and limitations

The present study has several important strengths. First, it comprehensively evaluated both physiological and psychosocial outcomes by simultaneously assessing overactive bladder symptoms, sexual function, sexual quality of life, depressive symptoms, bladder diary parameters, and objective pelvic floor muscle performance using digital palpation and EMG biofeedback measurements. Second, intervention fidelity was strengthened through prospective adherence monitoring. All participants completed the adherence monitoring forms, and more than 90% completed at least 90% of the prescribed exercise sessions, demonstrating excellent compliance with the intervention protocol. Third, unlike many previous studies that primarily focused on women with urinary incontinence, this randomized controlled trial specifically investigated women with overactive bladder, thereby providing clinically relevant evidence for this patient population.

Several limitations should also be acknowledged. First, self-reported questionnaires may have been subject to recall and reporting bias because participants were asked to report their experiences over the preceding four weeks. Second, participants were recruited from a single geographical region, which may limit the generalizability of the findings to populations with different demographic or cultural characteristics. Third, although pharmacological treatment remained unchanged throughout the study, residual confounding related to medication use cannot be completely excluded. Fourth, although the trial was registered retrospectively, ethical approval was obtained before participant recruitment and the study protocol remained unchanged throughout the study. Finally, although one primary outcome and several predefined secondary outcomes were evaluated, multiple statistical comparisons were performed without formal adjustment. Therefore, secondary outcome findings should be interpreted with appropriate caution despite the consistency observed across subjective questionnaires, bladder diary variables, and objective pelvic floor muscle assessments.

Conclusion

Women receiving pelvic floor muscle training demonstrated better sexual function, lower depressive symptom scores, and improved pelvic floor muscle performance. Female sexual function (FSFI) was the predefined primary outcome of this trial, whereas findings related to depressive symptoms, pelvic floor muscle performance, and bladder outcomes should be interpreted as exploratory secondary findings. These findings highlight the potential value of integrative approaches that concurrently assess sexual health and urinary function for the preservation and enhancement of pelvic floor integrity in women with OAB. Further studies are needed before such comprehensive strategies can be broadly implemented in clinical practice. Moreover, large-scale, multicenter investigations are warranted to elucidate the complex interplay between pelvic floor health, sexual quality of life, depression, and sexual function across broader populations.

Authors' contributions

Filiz YILMAZ ALADAĞ (Conceptualization [equal], Methodology [equal], Investigation [lead], Writing—review & editing [equal]), Nezihe KIZILKAYA BEJİ (Conceptualization [equal], Methodology [equal], Supervision [equal], Writing—review & editing [equal])

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Data availability

Data supporting research findings are available to the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

Ethical approval was obtained from the Non-Interventional Clinical Research Ethics Committee of Istanbul Biruni University (Decision No: 2021/60 − 11, Date: 22.10.2021). Institutional permission was granted by Erzurum City Hospital. The study adhered to the Declaration of Helsinki principles. Written informed consent was obtained from all participants. All data were anonymized, and participants were informed that they could withdraw from the study at any stage. Necessary permissions for the use of the scales were obtained from the original authors. The research was accepted as a PhD thesis in Istanbul Biruni University Graduate Education Institute, Department of Obstetrics and Gynecology Nursing in 2025.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.