Abstract
The effects of the oral administration of salts of aspartic acid on endurance capacity
and metabolic responses to prolonged bicycle exercise have been investigated. Previous
reports in man and in animals have suggested that this treatment can increase the
capacity to perform muscular work by virtue of its effect on circulating ammonia levels.
Eight healthy young male subjects exercised to exhaustion on a bicycle ergometer at
a work load requiring approximately 75% of maximum oxygen uptake. This work test was
performed after placebo administration or after ingestion of 6 g of potassium-magnesium
aspartate over a 24-h period, using a double-blind protocol. Exhaustion was reached
after 82.7 ± 23.5 min (mean ± SD) following aspartate treatment and after 85.4 ± 26.5
min following the placebo. No differences in the blood glucose, lactate, or ammonia
concentrations or in the plasma free fatty acid concentration between the two treatments
were observed. The respiratory exchange ratio was the same on both occasions. These
results show no beneficial effect of oral aspartate administration on work capacity
in man and also suggest that the metabolic processes that occur during exercise are
not influenced by this treatment.
Key words
aspartate - exercise - fatigue - metabolism
