| L-arginine-L-aspartate
is widely used by athletes for its potentially ergogenic properties.
However, only little information on its real efficacy is available
from controlled studies. Therefore, we evaluated the effects of prolonged
supplementation with L-arginine-L-aspartate on metabolic and cardiorespiratory
responses to submaximal exercise in healthy athletes by a double blind
placebo-controlled trial. Sixteen healthy male volunteers (22 ± 3
years) performed incremental cycle spiroergometry up to 150 watts
before and after intake of L-arginine-L-aspartate (3 grams per day)
or placebo for a period of 3 weeks. After intake of L-arginine-L-aspartate,
blood lactate at 150 watts dropped from 2.8 ± 0.8 to 2.0 ± 0.9 mmol·l-1
(p < 0.001) and total oxygen consumption during the 3-min period
at 150 watts from 6.32 ± 0.51 to 5.95 ± 0.40 l (p = 0.04) compared
to placebo (2.7 ± 1.1 to 2.7 ± 1.4 mmol·l-1; p = 0.9 and
6.07 ± 0.51 to 5.91 ± 0.50 l; p = 0.3). Additionally, L-arginine-L-aspartate
supplementation effected an increased fat utilisation at 50 watts.
L-arginine and L-aspartate seem to have induced synergistic metabolic
effects. L-arginine might have reduced lactic acid production by the
inhibition of glycolysis and L-aspartate may have favoured fatty acid
oxidation. Besides, the results indicate improved work efficiency
after L-arginine-L-aspartate intake. The resulting increases of submaximal
work capacity and exercise tolerance may have important implications
for athletes as well as patients.
KEY
WORDS: Nutrition, supplementation, amino acids, ergogenic, performance.
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