Çocuk Judocuların Antrenör Yönlendirmesi ve Eğitim Müdahalelerinin Hidrasyon Durumlarına Etkisi
Phase: NA
Conditions: Dehydration in Children, Dehydration
Sponsor: Kastamonu University

Official Title: The Impact of Brief One-time Education and Coach Encouragement on 
Hydration Status in Child Judo Athletes 
NCT number: E.912346 
Date of the document: 22nd of May 2025 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Study Design 
This within-subject experimental study examined the effects of coach encouragement and a 
brief one-time educational intervention (hereinafter referred to as education) on the hydration 
status of child judo athletes, compared to a no-intervention control, during a four-day training 
camp. As a within-subject design was adopted, each participant underwent all experimental 
conditions across different days. Athletes were unaware of the intervention conditions assigned 
to each day, and the educational session was presented without emphasizing its experimental 
nature. The order of conditions was fixed (control first, then coach encouragement, and finally 
education) to minimize potential carryover effects. The researcher conducting the hydration 
assessments was not blinded. Athletes and their legal guardians were informed about the nature 
of the study, and written consent was obtained from both parties. The study was conducted over 
four consecutive days. On the first day, anthropometric measurements were recorded. On the 
second, third, and fourth days, athletes' hydration status was assessed before and after training 
sessions under three different conditions: no intervention, coach encouragement, and 
educational intervention. 
 
The same training program was applied across all three experimental days. A detailed 
description of the sessions is presented in Table 1. All training sessions were conducted between 
10:00 and 12:00 under consistent environmental conditions (temperature, humidity) throughout 
the experimental period. 

Table 1. Judo training programme for child athletes during the experimental period 
Content 
Duration (min) 
Warm-up 
20 
"Uchikomi" (Technique repetition; standing, different directions, etc.) 
20 
Ne-waza workout (groundwork techniques) 
20 
3  4 min"Ne-waza randori" (groundwork battle) 
11 
6  4 min"Tachi-waza Randori"  
34 
Cool-down  
15 
Total  
120 
Note: The same training program was applied across all three intervention days (Day 1, Day 2, and Day 3). 
Statistical Analysis 
All data analyses were performed using JASP (version 0.19.0) and IBM SPSS Statistics (version 
20.0). Descriptive statistics—such as means, standard deviations, and 95% confidence 
intervals—were calculated for participants’ physical characteristics and variables related to the 
first morning urine samples. Normality was assessed by examining the Shapiro–Wilk test 
results and evaluating skewness and kurtosis values, with thresholds of ±2 being considered 
acceptable. Changes in USG across the three experimental conditions (i) no fluid intake 
guidance during training, (ii) fluid intake encouraged by the coach, and (iii) pre-training 
hydration education—were analyzed using a two-way repeated measures ANOVA (2 [time: pre- 
vs post-training] × 3 [experimental conditions]). Sphericity was evaluated with Mauchly’s test, 
and where violations occurred, the Greenhouse–Geisser correction was applied to adjust for the 
degrees of freedom. In cases where significant main or interaction effects were detected, post 
hoc comparisons were conducted using Holm’s adjustment for multiple testing. To determine 
whether hydration status (classified as hydrated or hypohydrated based on USG thresholds) 
changed significantly from pre- to post-training, McNemar’s test for paired nominal data was 
subsequently employed, and exact p-values were computed using the exact binomial test. Given 
the ordinal scale of urine color (UC) scores, changes from pre- to post-training were assessed 
using the non-parametric Friedman test. When significant differences were observed, 
Conover’s post hoc test with appropriate correction for multiple comparisons was applied. The 

significance level was set at p < 0.05. Effect sizes were reported as Cohen’s d for post hoc 
comparisons, eta squared (η²) for ANOVA, and Kendall’s W for the Friedman test.