Anxiety, Muscle Damage, Nutrition, Healthy, Self Confidence, Time Restricted Eating
Conditions
Keywords
Time Restricted Eating, Muscle Damage, Anxiety, Self Confidence, Martial Arts
Brief summary
This study investigates the effects of a 5-month early time-restricted eating (e-TRE) intervention on body composition, muscle damage biomarkers, and psychological variables in highly trained young male judo athletes. One hundred participants were randomly assigned to either an e-TRE group or a control group. The e-TRE group followed a 16:8 fasting protocol (07:00-15:00 eating window) while maintaining their usual training program, whereas the control group maintained habitual dietary patterns. Outcomes included changes in body composition (BMI, body fat, skeletal muscle mass), muscle damage biomarkers (CK, LDH, ASAT, ALAT, uric acid, CRP, total bilirubin), and psychological measures (cognitive anxiety, somatic anxiety, and self-confidence assessed using CSAI-2). Measurements were taken at baseline and after the intervention period. The aim of the study is to determine whether e-TRE can improve physiological recovery and psychological readiness in combat sport athletes without negatively affecting performance-related variables.
Detailed description
This study was designed to evaluate the effects of a 5-month early time-restricted eating (e-TRE) intervention on physiological and psychological outcomes in highly trained young male judo athletes. The study included 100 participants recruited from competitive judo teams in Tunisia. Participants were randomly assigned to either an e-TRE group or a control group in a 1:1 ratio. The e-TRE group followed a structured 16:8 time-restricted eating protocol, consuming all daily energy intake within an 8-hour window from 07:00 to 15:00, followed by a 16-hour fasting period. During fasting hours, only non-caloric beverages were permitted. The control group maintained their habitual dietary intake and meal timing without any modifications. Both groups continued their regular judo training program, consisting of 5-6 training sessions per week, including technical drills, sparring (randori), and strength and conditioning exercises. Anthropometric and biochemical measurements were collected at baseline (T0) and after the 5-month intervention (T1). Psychological assessments were conducted before monthly competitions throughout the study period. Blood samples were collected under standardized resting conditions and analyzed using validated enzymatic and immunoassay techniques. Participants were required to meet strict inclusion criteria, including age 18-26 years, male sex, at least 3 years of judo training experience, and absence of metabolic, psychiatric, or chronic diseases. Exclusion criteria included use of medications or supplements affecting metabolism, prior experience with intermittent fasting, and conditions that could affect training or biomarker outcomes. The study was approved by the Ethics Committee of the Higher Institute of Sport and Physical Education of Ksar Said, University of Manouba, Tunisia (approval No. 0171823; organization's unique protocol ID: ISSEP-2026-023) and was conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from all participants prior to enrollment Statistical analyses included repeated-measures ANOVA to assess group × time effects, with significance set at p \< 0.05. Effect sizes were calculated using partial eta squared (η²).
Interventions
BEHAVIORALEarly Time-Restricted Eating (e-TRE)
The intervention consisted of a 16:8 early time-restricted eating protocol applied for 5 months. Participants consumed all meals between 07:00 and 15:00, followed by a fasting period from 15:00 to 07:00 the next day. Only non-caloric beverages were allowed during fasting hours. Participants continued their regular judo training (5-6 sessions per week) without modifications. Dietary guidance was provided to support adherence to the eating schedule.
Sponsors
University of Manouba
University of Salento
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Participants were randomly assigned in a 1:1 ratio to either an early time-restricted eating (e-TRE) group or a control group. The study followed a parallel design, with both groups participating simultaneously over a 5-month intervention period. The e-TRE group followed a 16:8 time-restricted eating protocol, while the control group maintained their habitual dietary practices.
Eligibility
Sex/Gender
MALE
Age
19 Years to 26 Years
Healthy volunteers
Yes
Inclusion criteria
* aged 19-26 years; * male judo players; c) with at least 3 years of judo training experience; * engaged in judo training 5-6 days per week; e) healthy, with no known chronic illnesses or conditions affecting metabolism, mental health, or physical performance; * willing to adhere to a 16:8 e-TRE protocol for the 5-month study period; * non-smokers, as smoking may affect anxiety levels and cardiovascular health; * not using any performance-enhancing drugs or supplements that could interfere with the study's measurements.
Exclusion criteria
* current musculoskeletal injuries or conditions that could limit participation in training or affect muscle damage biomarkers; * diagnosed psychiatric disorders or current treatment for anxiety or mood disorders, as these could interfere with psychological assessments; * use of medications affecting metabolism, muscle recovery, or psychological state (e.g., corticosteroids, antidepressants); * prior experience with time-restricted eating or intermittent fasting within the past year, as prior adaptation could impact study outcomes; * dietary restrictions or practices (e.g., vegan or keto diet) that could affect nutrient intake or metabolic markers; * diagnosed sleep disorders or irregular sleep patterns, as sleep quality could impact both muscle recovery and psychological parameters; * inability to commit to the structured training program over the study period.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Competitive Anxiety and Self-Confidence | Baseline and 5 months (pre-intervention and post-intervention) | Competitive anxiety and self-confidence will be assessed using the Competitive State Anxiety Inventory-2 (CSAI-2). This validated questionnaire measures three dimensions of pre-competition psychological state: cognitive anxiety, somatic anxiety, and self-confidence. Scores will be used to evaluate changes in athletes' psychological readiness, emotional response to competition, and perceived self-efficacy. The CSAI-2 consists of 27 items, divided into three subscales (9 items each). Each item is rated on a 4-point Likert scale ranging from 1 ("not at all") to 4 ("very much so"). Subscale scores are calculated by summing item responses, resulting in a score range of 9 to 36 for each dimension (cognitive anxiety, somatic anxiety, and self-confidence). Measurements will be taken at baseline (T0) and post-intervention (T1) to determine the effect of early time-restricted eating on competitive anxiety and self-confidence in young judo athletes. |
| Creatine kinase (CK) | Baseline and 5 months (pre-intervention and post-intervention)] | Creatine kinase (CK) will be used as a marker of muscle damage. Blood samples will be collected to assess changes in CK levels in response to the early time-restricted eating intervention. CK concentrations will be measured in U/L and compared between baseline (T0) and post-intervention (T1, 5 months) in judo athletes. |
| Lactate dehydrogenase (LDH) | Baseline and 5 months (pre-intervention and post-intervention) | Lactate dehydrogenase (LDH) will be used as a biomarker of muscle damage. LDH will be measured in U/L to assess changes induced by early time-restricted eating between baseline and post-intervention in judo athletes. |
| Aspartate aminotransferase (AST) | Baseline and 5 months (pre-intervention and post-intervention) | Aspartate aminotransferase (AST) will be measured as an indirect marker of muscle damage and metabolic stress. AST levels will be assessed in U/L to evaluate changes from baseline to post-intervention following early time-restricted eating in judo athletes. |
| Alanine aminotransferase (ALT) | Baseline and 5 months (pre-intervention and post-intervention) | Alanine aminotransferase (ALT) will be assessed as a biomarker related to muscle stress. ALT levels will be measured in U/L to determine changes following early time-restricted eating between baseline and post-intervention in judo athletes. |
| Uric acid | Baseline and 5 months (pre-intervention and post-intervention) | Uric acid will be measured as a metabolic and oxidative stress biomarker. Serum uric acid will be assessed in µmol/L to evaluate changes induced by early time-restricted eating in judo athletes. |
| C-reactive protein (CRP) | Baseline and 5 months (pre-intervention and post-intervention) | C-reactive protein (CRP) will be used as a systemic inflammation biomarker. CRP levels will be measured in mg/L to assess inflammatory response changes following early time-restricted eating between baseline and post-intervention in judo athletes. |
| Total bilirubin | Baseline and 5 months (pre-intervention and post-intervention) | Total bilirubin will be measured as a marker of oxidative stress and heme metabolism. Serum bilirubin levels will be assessed in µmol/L to evaluate changes induced by early time-restricted eating in judo athletes between baseline and post-intervention. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Body Mass Index (BMI) | Baseline and 5 months (pre-intervention and post-intervention) | Body Mass Index (BMI) will be calculated as body weight in kilograms divided by height in meters squared (kg/m²). BMI will be used to assess changes in overall body composition status following early time-restricted eating. |
| Body fat percentage | Baseline and 5 months (pre-intervention and post-intervention) | Body fat percentage will be assessed as an indicator of relative adiposity. Body fat percentage will be expressed as a percentage (%) and measured to evaluate changes following the early time-restricted eating intervention. |
| Skeletal muscle mass | Baseline and 5 months (pre-intervention and post-intervention) | Skeletal muscle mass will be assessed as an indicator of lean muscle tissue. Skeletal muscle mass will be measured in kilograms (kg) to evaluate changes induced by early time-restricted eating. |
Countries
Tunisia
Outcome results
None listed