Effects of branched chain amino acids, l-citrulline, and alpha-glycerylphosphorylcholine supplementation on exercise performance in trained cyclists: a randomized crossover trial
Harrington RN
Published in Journal of the International Society of Sports Nutrition
Methodology
Randomized, double-blind crossover trial in 30 trained male cyclists comparing 7 days of a supplement containing 8 g BCAAs, 6 g L-citrulline and 300 mg alpha-GPC with a maltodextrin placebo across a 20 km time trial and a high-intensity endurance cycling test.
Key Findings
Peak power in the 20 km time trial increased significantly with the supplement (p = 0.003) and time to fatigue increased 36.2% (p = 0.001), but time to completion, average power and perceived exertion did not improve.
Conclusions
A combination containing alpha-GPC improved peak power and time to fatigue in trained cyclists, though average performance measures were unchanged.
Limitations
Multi-ingredient formula means effects cannot be attributed to alpha-GPC specifically; several primary performance measures showed no benefit; male-only sample.
Supplements Studied
There was a significant increase (p = .003) in peak power in the 20 km TT... There was no significant improvement in time to completion, average power, OMNI rating of perceived exertion, or VAS responses on perceived exertion in the TT test.
Outcomes Measured
There was a significant increase (p = .003) in peak power in the 20 km TT (354.27 ± 87.88 and 321.67 ± 63.65, for supplement and placebo trials, respectively).
Study Details
Access Study
Disclosures
Funding
Not stated; no competing interests reported
This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.