TRX Exercises and Gastrointestinal Health in Swimmers

This study was conducted as an 8-week randomized controlled trial with 32 male swimmers. Participants were randomly divided into two groups (TRX, n=16 and Control, n=16) by Random Allocation Software. The TRX group and the control group were administered the Bristol Stool Scale and a questionnaire including defecation habits before and after the 8-week program. The shape of the feces differs according to the duration of their stay in the colon. For this reason, BSFS has been recognized as a reliable and rapid indicator of transit time. According to this scale, individuals' stools are classified into 7 groups, with Form 1 and Form 2 representing slow passage of stool through the colon, Form 3 and Form 4 representing normal passage of stool through the colon, and Form 5 and Form 6 representing rapid passage of stool through the colon and impaired rectal sensitivity.

Before starting the exercise program, the TRX group was subjected to a training session. The exercise protocol, questionnaire and scales were administered in a gym at a temperature of 20-24°C. No ergogenic supplements were given to the athletes during the study and they were asked to follow their normal diet. Since our study aimed to compare the effect of TRX exercise model with constipation and bowel habits, no additional food (apricots, plums, etc.) and medication (laxatives, etc.) were given to the children.

During the study period, all training sessions were performed between 12.00-13.30 (±1 hour), Monday-Wednesday-Friday. The athletes participated in a total of 24 exercise sessions 3 days a week for 8 weeks. Exercise intensity was determined according to TRX stability, vectorial and pendulum principles.

A total of 10 exercises were applied to the participants. These exercises consisted of movements for the upper body, lower body and core. Core exercises include Bicycle Crunch and Knee Tuck; lower extremity exercises include Calf Rise, Hamstring Curl, Lateral Skater With Stick and TRX Squat Jump; and finally upper extremity exercises include Chest Fly, Chest Press, Biceps Curl and TRX Inverted Row. Swimmers were given 45 seconds rest time between sets and 2 minutes rest time between each exercise. The Bristol stool scale and questionnaires including defecation habits were administered before starting the exercise program and after the 8th week of the training program was completed. No side effects or injuries were observed during the training.

• Exercise (Behavioral), also known as Trx and Swimming: In this model, a specific intervention is applied to the experimental group (TRX and swimming). Measurements are conducted before and after the intervention (pre-test / post-test). In the study, the TRX group performed TRX exercises in addition to their regular swimming training for 8 weeks, three days per week, for 45-60 minutes per session.
• Randomized Controlled Trial (Other), also known as Swimming: The control group participated only in their regular swimming training program for 8 weeks. No additional intervention, such as another exercise program, was applied to the control group during the stady.

Primary outcomes

• Height and Body Weight/Body Mass Index (BMI) [Time Frame: 8 Week]: Body Weight;Measured in kilograms (kg). Height; Measured in meters (m). Body Mass Index (BMI) Calculated as body weight in kilograms divided by height in meters squared (kg/m²). Body Composition was calculated using the formula kg/m2.

Secondary outcomes

• Bristol Stool Form Scale [8 week]: Was developed by Lewis and Heaton at the University of Bristol to assess the colonic rates of individuals. The shape of the feces differs according to the duration of their stay in the colon. For this reason, Bristol Stool Form Scale has been recognized as a reliable and rapid indicator of transit time. According to this scale, individuals' stools are classified into 7 groups, with Form 1 and Form 2 representing slow passage of stool through the colon, Form 3 and Form 4 representing normal passage of stool through the colon, and Form 5 and Form 6 representing rapid passage of stool through the colon and impaired rectal sensitivity.

Other outcomes

• Questionnaire on Defecation Habits [8 week]: Description: Bowel habits and gastrointestinal symptom burden were evaluated using a structured, self-administered questionnaire assessing defecation postponement behavior and underlying reasons, stool frequency and timing, and the severity of common gastrointestinal symptoms, quantified on a 5-point Likert scale (0 = never to 4 = always).

Sex: Male, ages: 9 Years to 13 Years, accepts healthy volunteers

Inclusion Criteria:

* Who have been performance athletes for at least 2 years
* Male swimmers aged 9-13 years who trained in swimming at least 3 days per week,
* Had not participated in any resistance training other than regular swimming training in the last six months,
* Did not have chronic diseases such as asthma or chronic heart disease were included in the study.

Exclusion Criteria:

* Athletes with chronic diseases such as asthma or chronic heart disease, non-performance swimmers,
* Those who had participated in any resistance training other than regular swimming training within the last six months,
* Athletes whose parental consent forms were not obtained, those who missed more than three training sessions, and those who provided misleading answers or did not properly complete the questionnaire were excluded from the study.

• Results publication: Yildiz Y, Kahve AN. Effects of 8-week TRX exercise program on bowel habits and gastrointestinal symptoms in competitive male swimmers aged 9-13: a randomized controlled trial. BMC Sports Sci Med Rehabil. 2026 Jun 15. doi: 10.1186/s13102-026-01806-6. Online ahead of print. PMID 42298701

• Study Protocol (PDF, 2025-04-24)
• Informed Consent Form (PDF, 2025-04-24)