TENS Versus Foam Rolling for Muscle Recovery After Eccentric Exercise in Elite Female Volleyball Players (TENS-FR-VB)

TENS Versus Foam Rolling for Recovery After Eccentric Exercise-Induced Muscle Damage in Elite Female Volleyball Players: A Comparative Study

Purpose:

This study compared two recovery methods-transcutaneous electrical nerve stimulation (TENS) and foam rolling (FR)-for muscle recovery after intense exercise in elite female volleyball players.

Background:

Delayed-onset muscle soreness (DOMS) is common after intense training and can reduce athletic performance. TENS uses mild electrical currents applied through the skin to reduce pain and improve blood flow. Foam rolling uses a cylindrical device to apply pressure to muscles. Both methods are widely used by athletes, but no previous study has directly compared them in elite female volleyball players.

Participants:

Thirty elite female volleyball players from Iran's Premier League, aged 18-28 years, with at least five years of competitive experience.

Procedures:

Participants completed a demanding lower-body exercise protocol designed to induce muscle soreness. They were then randomly assigned to one of three groups:

TENS group: received electrical stimulation to thigh muscles for 20 minutes Foam rolling group: performed self-massage with a foam roller for 20 minutes Control group: rested quietly for 20 minutes Interventions were applied 30 minutes after exercise and repeated 24 hours later.

Outcomes Measured:

Blood marker of muscle damage (creatine kinase [CK]) Vertical jump height Anaerobic sprint power Muscle soreness Measurements were taken before exercise and at 1, 24, and 48 hours afterward.

Hypothesis:

Both active recovery methods would reduce muscle damage markers and preserve jumping ability better than passive rest, with TENS potentially providing faster benefits.

Study Overview

• Status: Completed
• Conditions: Athletic Injuries; Muscle Recovery; Exercise-induced Muscle Damage; Delayed-Onset Muscle Soreness (DOMS)
• Intervention / Treatment: Device: Transcutaneous Electrical Nerve Stimulation (TENS); Other: Foam Rolling (FR)

Detailed Description

STUDY RATIONALE:

Delayed-onset muscle soreness (DOMS) develops 12-72 hours (h) after unaccustomed eccentric exercise and manifests as localized pain, swelling, and functional impairment. This is particularly significant for elite volleyball players, whose performance depends on explosive vertical jumping and sustained lower-body power. A single volleyball match may involve more than 100 maximal vertical jumps combined with rapid lateral movements, making the quadriceps, hamstrings, and gastrocnemius muscles susceptible to repeated eccentric loading during landing phases.

Transcutaneous electrical nerve stimulation (TENS) enhances local blood flow and activates large-diameter sensory fibers, which may accelerate metabolite clearance and modulate pain perception. Foam rolling (FR) applies bodyweight-driven compressive forces using a cylindrical device, with reported benefits including improved tissue compliance and reduced fascial restrictions. Despite growing interest in these modalities, direct head-to-head comparisons in elite female volleyball players are lacking.

STUDY DESIGN:

This was a prospective, randomized, controlled, parallel-group trial conducted at the Zahedan Olympic Village, Iran, between September and December 2020. The study employed a three-arm design comparing TENS, FR, and passive rest (control).

RANDOMIZATION AND ALLOCATION CONCEALMENT:

A researcher who was not involved in data collection generated the randomization sequence using computer software (Random Allocation Software, version 2.0). The sequence was generated using a simple randomization method with a 1:1:1 allocation ratio. Group assignments were placed in sequentially numbered, opaque, sealed envelopes, which participants opened only after completing all baseline assessments. This procedure ensured that neither participants nor investigators could predict group allocation prior to enrollment.

BLINDING:

Due to the nature of the interventions, participant blinding was not possible. However, the outcome assessor who conducted all functional performance tests and processed blood samples was blinded to group allocation throughout the study. Data analysis was performed by a statistician who was blinded to group codes until the analysis plan was finalized.

PARTICIPANT SELECTION:

Inclusion criteria:

Age 18-28 years At least five years of competitive volleyball experience Current participation in Iran's national Premier League Training frequency of at least five sessions per week Absence of musculoskeletal injury during the preceding six months

Exclusion criteria:

Use of anti-inflammatory medications or supplements Contraindications to TENS (cardiac pacemaker, epilepsy, pregnancy) Exposure to study interventions within the preceding four weeks Lower-body strength training within 72 hours prior to testing

SAMPLE SIZE:

Sample size was calculated a priori using G*Power software (version 3.1.9.7). Based on a repeated-measures analysis of variance (ANOVA) design with three groups, four time points, an expected effect size of f = 0.28, alpha = 0.05, power = 0.80, correlation among repeated measures of 0.65, and nonsphericity correction of 0.89, a minimum of 30 participants (10 per group) was required.

EXERCISE PROTOCOL:

All participants completed an eccentric exercise protocol consisting of five sets of 15 eccentric-focused repetitions on a 45° angled leg press, with the load fixed at 110% of the concentric one-repetition maximum (1RM). A 4-second controlled eccentric phase was paced by a digital metronome. This protocol reliably induces DOMS that peaks within 24-48 hours.

TENS INTERVENTION:

TENS was applied to the quadriceps and hamstrings of the dominant leg using a clinical-grade stimulator. Four self-adhesive electrodes were positioned over the rectus femoris and biceps femoris. Stimulation parameters: biphasic symmetric waveform; frequency 120-150 Hertz (Hz); pulse width 100 microseconds (μs); intensity 10-30 milliamperes (mA) adjusted to produce strong, comfortable paresthesia without visible muscle contraction; duration 20 minutes per session.

FOAM ROLLING INTERVENTION:

Participants used a medium-density foam roller (15 centimeters [cm] diameter × 45 cm length) following a standardized bilateral sequence targeting the quadriceps, hamstrings, iliotibial band, gastrocnemius-soleus complex, and gluteal muscles. Each muscle group was rolled for 45 seconds per side. Three complete cycles were performed, totaling approximately 20 minutes per session.

CONTROL CONDITION:

Participants in the control (CON) group rested quietly in a supine position for 20 minutes without receiving any therapeutic intervention.

TIMING:

Interventions began 30 minutes after completion of the eccentric protocol and were repeated 24 hours later, resulting in two intervention sessions.

OUTCOME ASSESSMENT:

All assessments were conducted at baseline (pre-exercise) and at 1, 24, and 48 hours postexercise by a single trained assessor blinded to group allocation.

Primary outcomes:

Serum creatine kinase (CK)-measured using enzymatic colorimetric assay Vertical jump height-assessed using Sargent jump test (best of three trials) Anaerobic peak power-derived from Running-based Anaerobic Sprint Test (RAST) (six maximal 35-meter sprints)

Secondary outcome:

4. Muscle soreness-quantified using 100-millimeter (mm) visual analog scale (VAS) during standardized bodyweight squat

STATISTICAL APPROACH:

Mixed-design repeated-measures ANOVA with Group (TENS, FR, CON) as the between-subject factor and Time (baseline, 1, 24, and 48 hours) as the within-subject factor. Greenhouse-Geisser corrections were applied when sphericity assumptions were violated. When significant interactions were observed, simple effects comparisons were conducted at each time point using estimated marginal means with the pooled within-cell error term. Bonferroni adjustments were applied for multiple pairwise comparisons. Effect sizes are reported as partial eta squared (η²p) for omnibus effects and Cohen's d for pairwise comparisons, accompanied by 95% confidence intervals (CI). Statistical significance was established at p < 0.05.

SAFETY MONITORING:

Participants were monitored for adverse events, including skin irritation at electrode sites, excessive soreness, or vasovagal responses during blood collection. A standardized adverse event form was completed after each session.

COMPLIANCE:

Participants were instructed to maintain habitual dietary and hydration practices and to abstain from analgesic or anti-inflammatory medications, alcohol, caffeine, and any recovery modalities outside the study protocol for 72 hours after the exercise bout. Compliance was monitored using daily self-report checklists.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Iran
  • Sistan and Baluchestan
    • Zahedan, Sistan and Baluchestan, Iran
      • Zahedan Olympic Village

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 18-28 years
• At least five years of competitive volleyball experience
• Current participation in Iran's national Premier League
• Training frequency of at least five sessions per week
• Absence of musculoskeletal injury during the preceding six months

Exclusion Criteria:

• Use of anti-inflammatory medications or supplements
• Contraindications to transcutaneous electrical nerve stimulation (TENS), including cardiac pacemaker, epilepsy, or pregnancy
• Exposure to the study interventions (TENS or foam rolling [FR]) within the preceding four weeks
• Lower-body strength training within 72 hours (h) prior to testing

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Transcutaneous Electrical Nerve Stimulation (TENS); Participants received transcutaneous electrical nerve stimulation (TENS) applied to the quadriceps and hamstrings of the dominant leg using a clinical-grade stimulator. Four self-adhesive electrodes (5 × 9 centimeters [cm]) were positioned over the rectus femoris and biceps femoris. Stimulation parameters: biphasic symmetric waveform; frequency 120-150 hertz (Hz); pulse width 100 microseconds (μs); intensity 10-30 milliamperes (mA) adjusted to produce strong, comfortable paresthesia without visible muscle contraction; duration 20 minutes per session. Interventions were applied 30 minutes after the eccentric exercise protocol and repeated 24 hours (h) later, resulting in two sessions.	Device: Transcutaneous Electrical Nerve Stimulation (TENS); Transcutaneous electrical nerve stimulation (TENS) was delivered using a clinical-grade stimulator (SL400; Berjis Medical Equipment Co., Tehran, Iran). Stimulation parameters: biphasic symmetric waveform; frequency 120-150 Hertz (Hz); pulse width 100 microseconds (μs); intensity 10-30 milliamperes (mA) individually adjusted to produce strong, comfortable paresthesia without visible muscle contraction. Each session lasted 20 minutes. Sessions were conducted 30 minutes postexercise and repeated at 24 hours.
Experimental: Foam Rolling (FR); Participants performed foam rolling (FR) using a medium-density, smooth-surface foam roller (15 centimeters [cm] diameter × 45 cm length). A standardized bilateral sequence targeted the quadriceps, hamstrings, iliotibial band, gastrocnemius-soleus complex, and gluteal muscles. Each muscle group was rolled for 45 seconds per side at a cadence of approximately 3 cm per second. Three complete cycles were performed, totaling approximately 20 minutes per session. Interventions were applied 30 minutes after the eccentric exercise protocol and repeated 24 hours (h) later, resulting in two sessions.	Other: Foam Rolling (FR); Foam rolling (FR) was performed using a medium-density, smooth-surface cylindrical foam roller (15 centimeters [cm] diameter × 45 cm length; Denafoam, Tehran, Iran). Participants followed a standardized bilateral rolling protocol targeting five muscle groups: quadriceps, hamstrings, iliotibial band, gastrocnemius-soleus complex, and gluteal muscles. Each muscle group was rolled for 45 seconds per side at approximately 3 cm per second. Three complete cycles were performed per session, totaling approximately 20 minutes. Sessions were conducted 30 minutes postexercise and repeated at 24 hours.
No Intervention: Control (CON); Participants in the control (CON) group rested quietly in a supine position for 20 minutes without receiving any therapeutic intervention. Rest periods were applied 30 minutes after the eccentric exercise protocol and repeated 24 hours (h) later, matching the timing of active intervention sessions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Serum Creatine Kinase (CK) Concentration	Serum creatine kinase (CK) activity was measured as a biomarker of exercise-induced muscle membrane disruption. Venous blood samples (5 milliliters [mL]) were collected from the antecubital vein into serum separation tubes. Samples were centrifuged at 1500 × g for 10 minutes, and serum was stored at -80 degrees Celsius (°C) until analysis. CK activity was measured using an enzymatic colorimetric assay (CK-NAC, International Federation of Clinical Chemistry [IFCC] kinetic method) on an automated analyzer. Results are expressed in units per liter (U/L).	Baseline (pre-exercise), 1 hour, 24 hours, and 48 hours postexercise
Change in Vertical Jump Height	Explosive lower-extremity power was assessed using the Sargent jump test. Participants stood adjacent to a wall-mounted measuring board graduated in 0.5-centimeter (cm) increments and marked their standing reach height with the dominant hand. They then performed a countermovement jump with an arm swing and touched the board at peak height. The best of three trials, separated by 30 seconds of rest, was recorded. Jump height was calculated as the difference between standing reach and peak jump height, expressed in centimeters (cm).	Baseline (pre-exercise), 1 hour, 24 hours, and 48 hours postexercise
Change in Anaerobic Peak Power	Anaerobic peak power was derived from the Running-based Anaerobic Sprint Test (RAST). Participants completed six maximal 35-meter (m) sprints with 10-second passive recovery intervals. Sprint times were recorded using dual-beam infrared timing gates (accuracy ±0.001 seconds). Power output was calculated using the formula: body mass × distance² ÷ time³. Results are expressed in watts per kilogram (W/kg).	Baseline (pre-exercise), 1 hour, 24 hours, and 48 hours postexercise

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Muscle Soreness	Perceived muscle soreness in the quadriceps was quantified using a 100-millimeter (mm) visual analog scale (VAS) during a standardized bodyweight squat (feet shoulder-width apart, descent to 90-degree knee flexion). The scale was anchored at "no soreness" (0 mm) and "worst possible soreness" (100 mm). This dynamic assessment has been validated for eccentric exercise-induced muscle pain.	Baseline (pre-exercise), 1 hour, 24 hours, and 48 hours postexercise

Collaborators and Investigators

• Sponsor: University of Sistan and Baluchestan
• Investigators: Principal Investigator: Mohammadreza Rezaeipour, MD, PhD, University of Sistan and Baluchestan

Publications and helpful links

General Publications

• Balasubramaniam U, Dissanayake R, Annabell L. Efficacy of platelet-rich plasma injections in pain associated with chronic tendinopathy: A systematic review. Phys Sportsmed. 2015 Jul;43(3):253-61. doi: 10.1080/00913847.2015.1005544. Epub 2015 Jan 20.
• Dupuy O, Douzi W, Theurot D, Bosquet L, Dugue B. An Evidence-Based Approach for Choosing Post-exercise Recovery Techniques to Reduce Markers of Muscle Damage, Soreness, Fatigue, and Inflammation: A Systematic Review With Meta-Analysis. Front Physiol. 2018 Apr 26;9:403. doi: 10.3389/fphys.2018.00403. eCollection 2018.
• Pinto Dos Santos D, Baessler B. Big data, artificial intelligence, and structured reporting. Eur Radiol Exp. 2018 Dec 5;2(1):42. doi: 10.1186/s41747-018-0071-4.

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2020
• Primary Completion (Actual): September 1, 2020
• Study Completion (Actual): December 30, 2020

Study Registration Dates

• First Submitted: February 22, 2026
• First Submitted That Met QC Criteria: February 22, 2026
• First Posted (Actual): February 27, 2026

Study Record Updates

• Last Update Posted (Actual): March 3, 2026
• Last Update Submitted That Met QC Criteria: February 27, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: TENS; Transcutaneous electrical nerve stimulation; Volleyball; Female athletes; Eccentric exercise; Vertical jump; Self-myofascial release; DOMS; Anaerobic power; Delayed-onset muscle soreness; Creatine kinase; Elite athletes; Neuromuscular performance; Foam rolling; Muscle damage recovery
• Additional Relevant MeSH Terms: Wounds and Injuries; Athletic Injuries; Therapeutics; Physical Therapy Modalities; Rehabilitation; Anesthesia and Analgesia; Electric Stimulation Therapy; Analgesia; Transcutaneous Electric Nerve Stimulation
• Other Study ID Numbers: IR.USB.REC.1399.007

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data will be made available upon reasonable request to the corresponding author.
• IPD Sharing Time Frame: Data will be available beginning immediately after publication with no end date.
• IPD Sharing Access Criteria: Researchers who provide a methodologically sound proposal may request access to de-identified data. Requests should be directed to the corresponding author (rezaeipour@ped.usb.ac.ir). Data requestors will need to sign a data access agreement.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No