Weight Cut Stress: the Hidden Struggle Beyond Fight Day

NCT06860204 | Completed

• 1 other identifier: ETU-REC-2024-10
• Study Type: observational
• Target: 25
• Locations: 1 country
• Sites: 1

Brief Summary

This study investigated the effects of rapid weight-cutting on stress in elite kickboxers by analyzing Heart Rate Variability (HRV) and subjective stress levels using a Visual Analog Scale (VAS). Data were collected across seven time points: Weigh-in Morning, Pre-Weigh-in, Post-Weigh-in, Post-Weigh-in Meal, Match Day Morning, Pre-Match, and Post-Match. Participants were divided into a weight-cutting group (n = 12), who reduced at least 5% of their body weight within 48 hours before competition, and a control group (n = 13), who maintained regular training and nutrition. HRV was measured using Apple Watch photoplethysmography under real-world conditions during the Senior European Kickboxing Championship in Greece. Results showed consistently lower RMSSD, indicating sustained physiological stress in the weight-cutting group. Subjective stress levels were also higher in this group, peaking before the weigh-in and exceeding pre-match levels. A notable decrease in subjective stress was observed immediately after the weigh-in, attributed to psychological relief rather than physical recovery. However, low RMSSD persisted on match day, indicating incomplete physiological recovery despite stabilized subjective stress. The control group demonstrated stable HRV and VAS. These findings highlight the prolonged autonomic strain of rapid weight-cutting, emphasizing the need for careful management to safeguard athlete health and performance.

Conditions

HRV; Psychological Adaptation

Keywords

Rapid weight loss; weight-cutting; elite kickboxers; heart rate variability; RMSSD

Outcome Measures

Primary Outcomes (1)

• Heart Rate Variability (HRV) - RMSSD Changes Over Time

  Heart Rate Variability (HRV) was assessed using the Root Mean Square of the Successive Differences (RMSSD) to evaluate autonomic nervous system stress responses. RMSSD values were measured to determine the impact of rapid weight-cutting on physiological stress and recovery. Lower RMSSD values indicate higher physiological stress and impaired autonomic function.

  Baseline (Weigh-in Morning), immediately before weigh-in, immediately after weigh-in, post-weigh-in meal, morning of match day, immediately before match, immediately after match

Secondary Outcomes (1)

• Subjective Stress Levels (VAS Scores) Over Time

  Baseline (Weigh-in Morning), immediately before weigh-in, immediately after weigh-in, post-weigh-in meal, morning of match day, immediately before match, immediately after match

Study Arms (2)

weight-cutting group

Athletes in the weight-cutting group were defined as those who had lost at least 5% of their body weight within the 48 hours prior to weigh-in.

control group

Participants in the non-weight-cutting group did not engage in any weight-cutting procedures

Eligibility Criteria

• Age: 16 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

The study population consisted of elite male kickboxers competing at the Senior European Kickboxing Championship in Greece. Participants were aged 18 to 35 years and had a minimum of 5 years of competitive experience at the national or international level. Athletes were divided into two groups: Weight-Cutting Group (n = 12): Athletes who lost at least 5% of their body weight within 48 hours prior to weigh-in. Control Group (n = 13): Athletes who maintained their regular training and nutrition, with no more than 2% weight fluctuation before the competition. All participants underwent heart rate variability (HRV) assessments using photoplethysmography (PPG) via Apple Watch Series 8 and subjective stress evaluations using the Visual Analog Scale (VAS) at seven time points from weigh-in morning to post-match. Participants were selected based on strict inclusion and exclusion criteria to ensure comparability between groups.

You may qualify if:

• Elite male kickboxers aged between 18 and 35 years
• Minimum 5 years of competitive experience at the national or international level
• Actively competing in the Senior European Kickboxing Championship
• For the weight-cutting group: Must have lost at least 5% of body weight within the 48 hours prior to weigh-in

You may not qualify if:

• Athletes who lost between 3-4% of their body weight, as they do not fit into either group
• History of cardiovascular diseases
• History of metabolic disorders
• Any medical condition that could affect HRV measurements
• Current or recent injuries (within the last 3 months) that could impair performance or stress responses

Sponsors & Collaborators

• Erzurum Technical University: lead

Study Sites (1)

Erzurum Technical University, Faculty of Sport Sciences

Erzurum, Erzurum, 25050, Turkey (Türkiye)

Location

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Res. Ass. (Researcher)

Study Record Dates

• First Submitted: February 25, 2025
• First Posted: March 5, 2025
• Study Start: November 2, 2024
• Primary Completion: November 10, 2024
• Study Completion: November 10, 2024
• Last Updated: March 7, 2025

Record last verified: 2025-03

Data Sharing

• IPD Sharing: Will share
• Shared Documents: SAP, ANALYTIC CODE
• Time Frame: Start Date: Data will be available upon publication of study results (estimated \[insert expected publication year, e.g., 2025\]). End Date: Data will be available for 5 years after publication or until \[insert expected end year, e.g., 2030\], whichever comes first.
• Access Criteria: Researchers affiliated with academic institutions, sports science organizations, or health research centers conducting studies related to sports physiology, combat sports, weight-cutting, stress, or heart rate variability (HRV). Access will be granted only to those with a valid research proposal that aligns with the objectives of this study. Researchers must submit a formal request, including a study proposal and intended data use statement, to the corresponding author (Burak Karababa, burak.karababa@erzurum.edu.tr). Upon approval, data will be shared via secure data transfer methods (e.g., institutional repository, encrypted file sharing platform). Researchers must agree to data use terms, including confidentiality and ethical compliance, before accessing the dataset.

Locations

TU (1)