Purpose Exercise-related gastrointestinal complaints are frequently reported in young athletes; however, evidence regarding the effects of resistance-based training modalities on bowel habits is limited. The aim of this study was to investigate the effect of an 8-week TRX program on bowel habits and gastrointestinal system of male child swimmers.

Methods Thirty-two prepubertal male swimmers aged 9-13 years were voluntarily enrolled in the study. Participants were randomly allocated to either the TRX or control group. Both groups were evaluated using the Bristol Stool Scale and a questionnaire assessing defecation habits before and after the 8-week TRX exercise program.

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.

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.