Isometric Core Training and Swimming Performance in Adolescent Amputee Swimmers

Effects of a 12-Week Isometric Core Training Program on Trunk Endurance and 50-m Freestyle Performance in Adolescent Amputee Swimmers: A Randomized Controlled Trial

Adolescent amputee swimmers often experience challenges related to trunk stabilization, postural control, and efficient force transfer during swimming because of asymmetric biomechanics associated with limb loss. Core muscle training has been proposed as a potential dryland conditioning strategy to support swimming performance and trunk endurance in Para-swimmers; however, evidence from randomized controlled trials in adolescent amputee swimmers remains limited.

The purpose of this study is to investigate the effects of a 12-week supervised isometric core training program on trunk muscular endurance and 50-meter freestyle swimming performance in adolescent amputee swimmers. Participants will be randomly assigned to either an experimental group receiving additional isometric core training together with standard swimming training or a control group performing standard swimming training only.

Primary outcome measures will include 50-meter freestyle performance time. Secondary outcome measures will include trunk muscular endurance assessments such as the 20-second sit-up test, 20-second reverse sit-up test, supine bent-knee leg hold, and prone trunk-extension hold. Assessments will be performed before and after the 12-week intervention period.

The findings of this study may contribute to the development of evidence-based dryland conditioning programs for adolescent Para-swimmers with limb amputations.

Study Overview

• Status: Completed
• Conditions: Amputation; Sport; Paralympic Athletes
• Intervention / Treatment: Behavioral: Isometric Core Training; Other: Standard Swimming Training

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

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye), 34290
    • İstanbul Gelisim University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Upper- or lower-limb amputation
• Participation in at least two consecutive Turkish National Para-swimming -Championships
• Active training with regular competitive participation
• Age between 14 and 20 years
• Ability to participate in regular swimming and exercise training
• Written informed consent obtained from participants and/or parents/guardians

Exclusion Criteria:

• Discontinuation of regular training or competitive participation
• Acute musculoskeletal injury or cardiovascular condition preventing maximal exercise participation
• Refusal or inability to participate in the study protocol
• Failure to complete the intervention or assessment procedures

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental Group; Participants in the experimental group completed a 12-week supervised isometric core training program in addition to their regular swimming training. The intervention was performed three times per week and included individualized trunk stabilization and endurance exercises adapted to the athlete's level of amputation.	Behavioral: Isometric Core Training; Participants assigned to the experimental group completed a supervised 12-week isometric core training program in addition to their regular swimming training. The intervention was performed three times per week and included individualized exercises targeting trunk stabilization, abdominal endurance, and lumbopelvic control. Exercises were adapted according to the athlete's level of upper- or lower-limb amputation and included front plank, side plank, trunk-extension holds, bridge exercises, Pallof press holds, and bird-dog/dead-bug variations. Training duration and resistance were progressively increased throughout the intervention period.
Active Comparator: Control Group; Participants in the control group continued their regular swimming training program for 12 weeks without additional dryland core training.	Other: Standard Swimming Training; Participants assigned to the control group continued their regular swimming training program for 12 weeks without any additional dryland core training intervention. The swimming program consisted of routine in-water training sessions conducted at the Ankara Olympic Preparation Centre according to the standard preparation program for competitive Para-swimmers.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
50-m Freestyle Swimming Performance	Official 50-m freestyle race time measured using FINA-approved electronic timing equipment during national Para-swimming competitions.	Baseline and after 12 weeks of intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
20-second Sit-up Performance	Number of correctly completed sit-up repetitions performed within 20 seconds to assess trunk flexor endurance.	Baseline and after 12 weeks of intervention
20-second Reverse Sit-up Performance	Number of correctly completed reverse sit-up repetitions performed within 20 seconds to assess trunk extensor endurance.	Baseline and after 12 weeks of intervention
Supine Bent-knee Leg Hold Duration	Duration in seconds that participants maintained the supine bent-knee leg hold position to assess lumbopelvic endurance.	Baseline and after 12 weeks of intervention
Prone Trunk-extension Hold Duration	Duration in seconds that participants maintained the prone trunk-extension hold position to assess trunk extensor endurance.	Baseline and after 12 weeks of intervention

Collaborators and Investigators

• Sponsor: Istanbul Gelisim University

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2024
• Primary Completion (Actual): June 1, 2024
• Study Completion (Actual): June 1, 2024

Study Registration Dates

• First Submitted: May 7, 2026
• First Submitted That Met QC Criteria: May 28, 2026
• First Posted (Actual): June 2, 2026

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: May 28, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 2024-03-73

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Individual participant data sharing has not yet been determined. Data may be shared upon reasonable request after publication of the study results and following approval by the corresponding author and institutional ethics requirements. Participant confidentiality and privacy protections will be maintained.

Drug and device information, study documents

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