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

Not Applicable

Completed

• Conditions: Diet, Reducing
• Interventions: Dietary Supplement: calorie restriction diet

• Registration Number: NCT05017259
• Lead Sponsor: Chin Hsu

Brief Summary

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

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.

Study Timeline

• Study Start: 2019-08-17
• Primary Completion: 2019-09-26
• Study Completion: 2019-09-26
• Status Verified: 2021-08
• Study First Submitted: 2021-08-15
• Study First Submitted QC: 2021-08-17
• Last Update Submitted: 2021-08-17
• Study First Posted: 2021-08-23
• Last Update Posted: 2021-08-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 12

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
low carbohydrate trial	calorie restriction diet	The energy distribution was carbohydrate 10%, protein 40-50%, fat 40-50% in the LC trial.
high carbohydrate trial	calorie restriction diet	The energy distribution was carbohydrate 60-65%, protein 30-40%, fat 5-10% in the HC trial.

Primary Outcome Measures

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

Secondary Outcome Measures

Name	Time	Method
Taekwondo-specific reaction time in seconds assessed by Electromyography (EMG) signals	1 min	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.

Trial Locations

Locations (1)

National Taiwan University of Sport; 🇨🇳 Taichung, Taiwan