The effect of L-ornithine hydrochloride ingestion on performance during incremental exhaustive ergometer bicycle exercise and ammonia metabolism during and after exercise

Abstract

Objectives: L-ornithine has an important role in ammonia metabolism via the urea cycle. This study aimed to examine the effect of L-ornithine hydrochloride ingestion on performance during incremental exhaustive ergometer bicycle exercise and ammonia metabolism during and after exercise. Subjects/Methods: In all, 14 healthy young adults (age: 22.2 ± 1.0 years, height: 173.5 ± 4.6 cm, body mass: 72.5 ± 12.5 kg) who trained regularly conducted incremental exhaustive ergometer bicycle exercises after L-ornithine hydrochloride supplementation (0.1 g/kg, body mass) and placebo conditions with a cross-over design. The exercise time (sec) of the incremental ergometer exercise, exercise intensity at exhaustion (watt), maximal oxygen uptake (ml per kg per min), maximal heart rate (beats per min) and the following serum parameters were measured before ingestion, 1 h after ingestion, just after exhaustion and 15 min after exhaustion: ornithine, ammonia, urea, lactic acid and glutamate. All indices on maximal aerobic capacity showed insignificant differences between both the conditions. Results: Plasma ammonia concentrations just after exhaustion and at 15 min after exhaustion were significantly more with ornithine ingestion than with placebo. Plasma glutamate concentrations were significantly higher after exhaustion with ornithine ingestion than with placebo. Conclusions: It was suggested that, although the ingestion of L-ornithine hydrochloride before the exercise cannot be expected to improve performance, it does increase the ability to buffer ammonia, both during and after exercise.

L-ornithine hydrochloride ingestion increased carbohydrate oxidation but not lipid oxidation during submaximal endurance exercise following resistance exercise

“…This is converted to glucose by gluconeogenesis in the liver and released to blood. Meanwhile, substantial ammonia is produced in skeletal muscle during resistance exercise in this study as well as in the study by Demura et al [27]. Namely, it is inferred that glutamic acid, which is a glucogenic amino acid, is synthesized by ammonia buffering and more is synthesized in the L-ornithine hydrochloride ingestion condition.…”

“…However, the accentuation of lipid oxidation with L-ornithine hydrochloride ingestion was not found, and the contribution of carbohydrate oxidation to total energy production was greater. Demura et al [27] examined the effect of L-ornithine hydrochloride ingestion before incremental exhaustive ergometer bicycle exercise on metabolism of ammonia, which is produced during exercise. They reported that plasma ammonia concentration after exercise in the L-ornithine hydrochloride ingestion condition was significantly lower than that of the placebo ingestion condition.…”

Randomised controlled trial of the effects of L-ornithine on stress markers and sleep quality in healthy workers

“…Furthermore, it was shown that L-ornithine administration stimulated release of growth hormone [45,46], which is secreted as the largest pulse after the onset of sleep, and that there is a correlation between night-time growth hormone release and sleep satisfaction [47-49]. …”

Russian Consensus “Hyperammonemia in Adults”

“…Концентрация аммиака в плазме сразу после и через 15 мин после дополнительных нагрузок в группе L-орнитина был значительно ниже, чем в группе плацебо. Таким образом, L-орнитин увеличивал способность аммиачного буфера, как во время, так и после тренировки [95].…”