Calorie Restriction Diets on Weight Reduction, Post weigh-in Recovery and Exercise Performance in Athletes

Study Overview
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Brief Summary
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Low-carbohydrate diets are often used as weight-loss strategies by obese individuals and athletes. This diet has effects on oxidizing fat and suppressing appetite. But short term evidences are still few. In combat sports such as taekwondo, athletes prefer rapid weight loss to achieve a desired weight category. The purpose of this study was to investigate the impact of the low carbohydrate diet combined with strict calorie restriction on body composition and exercise performance in taekwondo athletes.

Detailed Description
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This study used a randomized cross-over design. Each participant completed a low carbohydrate and a high carbohydrate trial in a random order, separated by a 30-day wash-out period. Each trial comprised of a 7-day weight loss period, followed by an 18-hr recovery period. The purpose of this study was to investigate the effect of 7-day caloric restriction with low- or high-carbohydrate diet, combined with an 18-hr recovery period, on body weight loss and taekwondo-specific performance.

Official Title
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The Metabolomic Exploration of Low-carbohydrate and Calorie Restriction Diet on Weight Reduction, Post weigh-in Recovery and Exercise Performance in Taekwondo Athletes

Conditions
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Diet, Reducing

Intervention / Treatment
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* Dietary Supplement: calorie restriction diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Must have at least 6 years of Taekwondo training experience Must have participated in domestic or international competitions Exclusion Criteria: Smoking Cardiovascular disease Diabetes Hypertension Any medication in the past 3 months

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 24 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: low carbohydrate trial<br>The energy distribution was carbohydrate 10%, protein 40-50%, fat 40-50% in the LC trial. | Dietary Supplement: calorie restriction diet<br>* The 7-day low-calorie diet contained 15.8 ± 0.4 kcal/kg/d in both trials, divided into three meals a day.<br>|
| Active Comparator: high carbohydrate trial<br>The energy distribution was carbohydrate 60-65%, protein 30-40%, fat 5-10% in the HC trial. | Dietary Supplement: calorie restriction diet<br>* The 7-day low-calorie diet contained 15.8 ± 0.4 kcal/kg/d in both trials, divided into three meals a day.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body weight in kilograms assessed by air-displacement plethysmography (Bod Pod) | The body weight (kg) of participants was determined before and after calorie restriction intervention to evaluate the degree of weight loss. | 1 min | 
| Body fat mass in kilograms assessed by air-displacement plethysmography (Bod Pod) | The body fat mass (kg) of participants was determined before and after calorie restriction intervention to evaluate the degree of weight loss. | 1 min | 
| Lean body mass in kilograms assessed by air-displacement plethysmography (Bod Pod) | The lean body fat mass (kg) of participants was determined before and after calorie restriction intervention to evaluate the degree of weight loss. | 1 min | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Taekwondo-specific reaction time in seconds assessed by Electromyography (EMG) signals | The reaction time (sec) was measured before and after weight loss to assess the difference in exercise performance. The participants were asked to make the fist on the left hand as soon as they see a light signal, then start the taekwondo-specific movement. The reaction time was calculated as the time from the beginning of the light signal to the start of electromyography (EMG) signal of the left thenar muscles. The movement was performed 5 times. The average reaction time was used to arrive at one reported value. | 1 min |