Exercise-induced Muscle Damage is Reduced in Resistance Trained Athletes by Branch Chain Amino Acids

Study Overview
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Brief Summary
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It is well documented that exercise-induced muscle damage (EIMD) decreases muscle function and causes severe soreness and discomfort. Branched-chain amino acid (BCAA) supplementation has been shown to increase protein synthesis and decrease muscle protein breakdown, however, the effects of BCAAs on recovery from EIMD are unknown. Thus, the aim of this study was to examine the effects of a BCAA supplement on markers of muscle damage.

Official Title
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Exercise-induced Muscle Damage is Reduced in Resistance Trained Athletes by Branch Chain Amino Acids

Conditions
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Exercise-induced Muscle Damage

Intervention / Treatment
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* Dietary Supplement: Branch Chain Amino Acid (BCAA)
* Dietary Supplement: Placebo - asparmate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Resistance trained males Exclusion Criteria: - Muscular skeletal disorders

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 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: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: BCAA<br>Branched chain amino acid | Dietary Supplement: Branch Chain Amino Acid (BCAA)<br>* Supplementation lasted for a total of 12 days; this was based on previous research showing a positive with BCAA supplementation on markers of muscle damage. Participants ingested 10 g, twice per day (morning and evening) of BCAA . The BCAA supplement contained a ratio of 2:1:1 (leucine, isoleucine and valine, respectively). The BCAA was in powder form where each serving was mixed with  300 ml of water.<br>|
| Placebo Comparator: Asparmate<br>Placebo control containing no protein or carbohydrate | Dietary Supplement: Placebo - asparmate<br>* Supplementation lasted for a total of 12 days. Participants ingested an equivalent looking volume to 10 g of BCAA, twice per day (morning and evening) of placebo (aspartame based artificial sweetener). The BCAA supplement contained a ratio of 2:1:1 (leucine, isoleucine and valine, respectively). The artificial sweetener was in powder form where each serving was mixed with  300 ml of water.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximal voluntary contraction | Isometric MVC of the participants' dominant knee extensors was assessed using a strain gauge. MVCs were performed for 3 s with a 60 s rest between each repetition. | pre exercise, 24 h, 48 h, 72 h, 96 h post-exercise | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Limb girths | Mid-thigh and calf circumference was assessed as a measure of limb swelling using an anthropometric tape measure. Both measures were obtained with the participant in a standing position. | pre-exercise, 24h, 48h, 72h, 96h | 
| Vertical jump | Vertical jump (VJ) performance was assessed using the Vertec instrument. Participants performed a counter movement jump. | pre-exercise, 24h, 48h, 72h, 96h | 
| Creatine kinase | Plasma CK was determined from an earlobe capillary blood sample. The sample (30 microlitres) was analysed immediately using an automated, dry slide photospectrometer. | pre-exercise, 24h, 48h, 72h, 96h | 
| Muscle soreness | Muscle soreness - Participants were asked to perform and hold a squat (90° knee angle) whilst they rated their perceived muscle soreness on a 200 mm visual analogue scale. The scale consisted of a line from 0 mm (no pain) to 200 mm (unbearably painful). | pre-exercise, 24h, 48h, 72h, 96h |