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Effects of Core and Inspiratory Muscle Training on Muscle Oxygenation and Athletic Performance İn Young Soccer Players

Effects of Core and Inspiratory Muscle Training On Muscle Oxygenation and Athletic Performance İn Young Soccer Players

Status
Not yet recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07657065
Enrollment
54
Registered
2026-06-18
Start date
2026-08-01
Completion date
2027-12-01
Last updated
2026-06-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Athletic Performance, Muscle Oxygenation, Respiratory Function

Keywords

Youth Soccer, Core Training, Inspiratory Muscle Training, Near-Infrared Spectroscopy, Aerobic Capacity, Diaphragm

Brief summary

The purpose of this randomized controlled trial is to investigate the effects of core training and inspiratory muscle training (IMT) on muscle oxygenation and athletic performance in youth male soccer players aged 15-18. A total of 54 healthy soccer players will be included and randomly assigned into three equal groups: the Control Group, the Core Training Group, and the Core Training + IMT Group. All interventions will be implemented for 8 weeks in addition to routine soccer training sessions. Assessments will be performed at baseline (Week 0), mid-intervention (Week 4), and post-intervention (Week 8). The primary outcome measures of the study are aerobic capacity assessed by the Yo-Yo Intermittent Recovery Test Level 1 and muscle oxygenation parameters monitored via near-infrared spectroscopy (NIRS) using a MOXY monitor. Secondary outcome measures include sprint performance, agility, dynamic balance, core muscle strength and endurance, inspiratory muscle strength, lower extremity explosive power, and soccer-specific technical performance tests. Overall, this study aims to reveal the combined effects of core training and inspiratory muscle training on muscle oxygenation, respiratory functions, aerobic capacity, and soccer performance, while explaining the underlying physiological mechanisms in youth athletes.

Detailed description

Background: Soccer performance is a multidimensional structure resulting from the interaction of technical, tactical, psychological, and physical components. In modern soccer, players frequently perform high-intensity running, sprinting, directional changes, and repeated efforts. Therefore, aerobic capacity, recovery ability, and the efficiency of muscle oxygen utilization are of critical importance. Respiratory muscle fatigue during high-intensity exercise can limit performance by triggering the respiratory muscle metaboreflex, which reduces blood flow to peripheral muscles. Inspiratory muscle training (IMT) aims to attenuate these adverse effects by enhancing the strength and endurance of the diaphragm and auxiliary respiratory muscles. Similarly, core training improves trunk stability, enhances movement economy, optimizes force transfer along the kinetic chain, and contributes to athletic performance measures. Near-infrared spectroscopy (NIRS) is a non-invasive technology used to evaluate muscle oxygenation and hemodynamic responses during exercise. The MOXY monitor utilized in this study will allow real-time evaluation of muscle oxygen saturation (SmO2) and total hemoglobin (THb) levels. Objectives: The primary objective is to investigate the effects of core training and inspiratory muscle training on muscle oxygenation and aerobic performance in youth male soccer players. Secondary objectives are to examine changes in maximal inspiratory pressure, sprint performance, agility, dynamic balance, core strength/endurance, lower extremity explosive power, and soccer-specific technical skills. Study Design & Interventions: This study is designed as a three-arm, parallel-group, randomized controlled trial involving 54 healthy male soccer players. Participants will be randomly allocated into one of three groups: 1. Control Group: Continues routine soccer training only. 2. Core Training Group: Receives a structured core training program in addition to routine soccer training. 3. Core Training + IMT Group: Receives both the core training program and inspiratory muscle training in addition to routine soccer training. The core training program will be implemented 3 days a week, lasting approximately 20-25 minutes prior to routine soccer practices. The program is structured on progressive overload principles, gradually increasing duration and difficulty. IMT will be performed 3 days a week using a threshold device. Participants will complete 2 sets of 30 breaths per session. Training intensity will start at 50% of maximal inspiratory pressure (MIP) and progress weekly up to approximately 70% MIP. Assessments & Statistical Analysis: All assessments will be conducted at baseline (Week 0), mid-intervention (Week 4), and post-intervention (Week 8). Primary outcomes include aerobic capacity (Yo-Yo IR1 distance) and muscle oxygenation parameters (SmO2, desaturation/reoxygenation rates, and THb). Secondary outcomes include 20-meter sprint (manual stopwatch), Illinois agility test, Y-Balance test, core strength/endurance tests, Standing Long Jump, MIP (cmH2O), Modified 10-Meter Dribbling Test, and the Wall Passing Accuracy Test. Linear mixed-effects models will be used to analyze group and time effects. Statistical significance will be set at p \< 0.05.

Interventions

BEHAVIORALCore Training Program

A structured, progressive core stability training program targeting trunk and abdominal musculature. The exercises will be conducted 3 days a week for 8 weeks, taking approximately 20-25 minutes before soccer practices.

DEVICEInspiratory Muscle Training (IMT)

Inspiratory muscle training performed using a threshold device. The protocol consists of 2 sets of 30 breaths per session, 3 days a week for 8 weeks. Training intensity starts at 50% of maximal inspiratory pressure (MIP) and progresses up to 70% MIP.

Sponsors

Istinye University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE

Intervention model description

This three-arm, parallel-group, randomized controlled trial investigates the isolated and combined effects of core training and inspiratory muscle training (IMT) added to routine training in youth soccer players. Participants will be randomly allocated into three groups: Control Group: Routine soccer training only Core Training Group: Routine training + Core training Combined Group: Routine training + Core training + IMT The intervention will last 8 weeks, with assessments at week 0 (pre-test), week 4 (mid-test), and week 8 (post-test). This design allows for the evaluation of both within-group changes over time and between-group differences. Utilizing multiple measurement time points enables monitoring the dynamic nature of the adaptation process and determining the time-course effects of the interventions.

Eligibility

Sex/Gender
MALE
Age
15 Years to 18 Years
Healthy volunteers
Yes

Inclusion criteria

* Being between 15 and 18 years of age. * Being a male soccer player. * Actively and regularly participating in trainings at Alagöz Soccer Club. * Having participated in regular soccer training for at least the last 6 months. * Being able to continue routine trainings throughout the study period. * Being fully informed about the research. * Having obtained voluntary informed consent, and parental/guardian consent for participants under 18 years of age. * Having the cognitive and physical capacity to understand and fulfill the specific test and exercise instructions.

Exclusion criteria

* Having a history of lower extremity, trunk-core, or athletic performance-limiting injury within the last 6 months. * Having undergone orthopedic lower extremity or spine surgery within the last 1 year. * Having active musculoskeletal pain or any orthopedic/neurological condition that prevents exercise. * Having any health condition that prevents the safe execution of balance, sprint, agility, jump, or core endurance tests. * Having asthma, chronic respiratory system diseases, exercise-induced bronchospasm, cardiovascular disease, or a physician-imposed restriction on high-intensity exercise that could affect respiratory muscle or exercise testing. * Having open wounds, infections, or severe skin sensitivity that prevents the application of sensors placed on the skin. * Currently participating in another structured respiratory muscle training or structured core exercise program that could affect the study results. * Having a body mass index (BMI) of 30 kg/m² or above. * Being deemed unsuitable for the study by the researcher due to safety concerns. * Withdrawal from the study at the request of the participant or their parent/guardian. * Missing two consecutive exercise sessions or having an insufficient overall attendance rate. * Developing an exercise-preventing injury or illness during the study period. * Occurrence of any safety risk during testing or exercise sessions. * Non-compliance with the study protocol. * Starting another additional exercise program during the study. * Technical inability to obtain reliable measurement data.

Design outcomes

Primary

MeasureTime frameDescription
Aerobic CapacityBaseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Assessed using the Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1) to determine the total distance covered in meters.
Muscle Oxygen Saturation (SmO2)Baseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Measured in percentage (%) during exercise using near-infrared spectroscopy (NIRS) via a MOXY monitor to evaluate muscle oxygenation.
Total Hemoglobin (THb)Baseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Measured in arbitrary units or micro-molar concentrations using a MOXY monitor (NIRS technology) to assess local blood volume changes and muscle hemodynamics.

Secondary

MeasureTime frameDescription
20-Meter Sprint PerformanceBaseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Assessed using a 20-meter sprint test with a manual stopwatch to measure running speed in seconds.
Agility PerformanceBaseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Measured using the Illinois Agility Test to evaluate the participant's ability to change direction quickly, recorded in seconds.
Dynamic BalanceBaseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Assessed using the Y-Balance Test (YBT) to measure dynamic balance and stability in anterior, posteromedial, and posterolateral directions, recorded in centimeters.
Core Muscle Strength and EnduranceBaseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Evaluated using core endurance tests (such as plank, side bridge, and trunk flexor/extensor endurance tests) to measure the holding time in seconds.
Lower Extremity Explosive PowerBaseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Measured using the Standing Long Jump test to evaluate horizontal explosive power, recorded in centimeters.
Maximal Inspiratory Pressure (MIP)Baseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Measured using a digital respiratory pressure meter (or PowerBreathe device) to evaluate maximal inspiratory muscle strength, recorded in cmH2O.
Soccer-Specific Dribbling PerformanceBaseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Assessed using the Modified 10-Meter Dribbling Test to measure soccer-specific ball control and speed, recorded in seconds.
Soccer Passing AccuracyBaseline (Week 0), Mid-intervention (Week 4), and Post-intervention (Week 8)Measured using the Wall Passing Accuracy Test to evaluate soccer-specific technical passing precision, recorded as a total accuracy score.

Countries

Turkey (Türkiye)

Contacts

CONTACTAbdurrahim Eyüp Canbaloglu, MSc
abdurrahim.eyup@gmail.com+90 5346492322
PRINCIPAL_INVESTIGATORAbdurrahim Eyüp CANBALOĞLU, MSc

IĞDIR UNİVERSİTY

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 19, 2026