High plasma citrulline and arginine levels ensured by sustained-release citrulline supplementation in rats

The Effect of Citrulline Supplementation on Lactic Acid Blood Level and Oxygen Saturation (SaO2) in Submaximal Physical Activity

An achievement in sport is one of the benchmarks of success of every athlete. One of the causes of the performance degradation is fatigue due to the formation of lactic acid. Supplements are proved to improve the performance in athletes. The purpose of this study was to determine the effect of citrulline supplementation on lactic acid levels and oxygen saturation on submaximal physical activity. Fatigue can be seen from lactic acid levels in subjects who have performed physical activity. This research method used randomized group pretest postest group design. The subjects used were male students of pencak silat airlangga university, and divided into two groups. The first group was given placebo and the second group was given citrulline. Each group was given the same treatment of three minutes of submaximal physical activity using an ergocycle. Before and after doing the activity the blood lactic acid and oxygen saturation of the subject was checked. The result of the data showed that lactic acid and oxygen saturation in both groups had p<0,05. Citrulline supplementation had effect on lactic acid and oxygen saturation. The results of the research showed that the group given with citrulline had significant effect on lactic acid and oxygen saturation before and after treatment.

l-Citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humans

The purpose of this study was to compare the effects of l-citrulline (Cit) and l-arginine (Arg) supplementation on nitric oxide (NO) biomarkers, pulmonary O2 uptake (V̇o2) kinetics, and exercise performance. In a randomized, placebo (Pla)-controlled, crossover study, 10 healthy adult men completed moderate- and severe-intensity cycling exercise on days 6 and 7 of a 7-day supplementation period with Pla, Arg (6 g/day), and Cit (6 g/day). Compared with Pla, plasma Arg concentration was increased by a similar magnitude with Arg and Cit supplementation, but plasma Cit concentration was only increased ( P < 0.001) with Cit supplementation. Plasma nitrite (NO2−) concentration was increased with Arg supplementation ( P < 0.05) and tended to increase with Cit supplementation ( P = 0.08) compared with Pla (83 ± 25, 106 ± 41, and 100 ± 38 nM with Pla, Arg, and Cit, respectively); however, mean arterial blood pressure was only lower ( P < 0.05) after Cit supplementation. The steady-state V̇o2 amplitude during moderate-intensity cycle exercise was not significantly different between supplements, but Cit lowered the V̇o2 mean response time (59 ± 8 and 53 ± 5 s with Pla and Cit, respectively, P < 0.05) during severe-intensity exercise, improved tolerance to severe-intensity exercise (589 ± 101 and 661 ± 107 s with Pla and Cit, respectively), and increased the total amount of work completed in the exercise performance test (123 ± 18 and 125 ± 19 kJ with Pla and Cit, respectively, P < 0.05). These variables were not altered by Arg supplementation ( P > 0.05). In conclusion, these results suggest that short-term Cit, but not Arg, supplementation can improve blood pressure, V̇o2 kinetics, and exercise performance in healthy adults.