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

Lead sponsor

Northumbria University is the lead sponsor of 156 studies on the registry; 22 are open to participants now.

Study arms

• Experimental
  BCAA

  Branched chain amino acid

  Dietary Supplement: Branch Chain Amino Acid (BCAA)

• Placebo comparator
  Asparmate

  Placebo control containing no protein or carbohydrate

  Dietary Supplement: Placebo - asparmate

Interventions

• Dietary supplementBranch Chain Amino Acid (BCAA)

  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.

• Dietary supplementPlacebo - asparmate

  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.

Primary outcomes

1. 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.

   Time frame: pre exercise, 24 h, 48 h, 72 h, 96 h post-exercise

Secondary outcomes

1. 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.

   Time frame: pre-exercise, 24h, 48h, 72h, 96h

2. Vertical jump

   Vertical jump (VJ) performance was assessed using the Vertec instrument. Participants performed a counter movement jump.

   Time frame: pre-exercise, 24h, 48h, 72h, 96h

3. 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.

   Time frame: pre-exercise, 24h, 48h, 72h, 96h

4. 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).

   Time frame: pre-exercise, 24h, 48h, 72h, 96h

Publications

• Howatson G, Hoad M, Goodall S, Tallent J, Bell PG, French DN. Exercise-induced muscle damage is reduced in resistance-trained males by branched chain amino acids: a randomized, double-blind, placebo controlled study. J Int Soc Sports Nutr. 2012 Jul 12;9:20. doi: 10.1186/1550-2783-9-20. eCollection 2012. PubMed 22569039 ↗