Nitrate Supplementation Combined With Citrulline Intake Has An Effect On The Performance Of Young Cyclists

Background and Rationale

The use and trends of performance enhancement substance have increased over the last decade, especially among the pre-teenagers and teenagers. Nitrogen oxide (NO) is a signaling molecule in the cardiovascular framework and additionally in different cell types and furthermore prevents the development of atherosclerosis. NO produced by L-arginine via endothelial NO synthetase (eNOS), acquires a vital role in controlling endothelium-subdued vasodilatation while retaining platelets and platelets attached to the endothelial cell layer of the veins and preventing the expansion of smooth muscle cells (Christensen, Nyberg & Bangsbo, 2013). NO further demonstrates the combination for radiological oxygen species, including avoidance of LDL-cholesterol oxidation. Thus, the reduced bioavailability of NO caused by endothelial disability is associated with the reduction in the chances of atherosclerotic coronary artery disease.

In order to increase NO-needed responses, oral L-arginine therapy in humans has been extensively studied in order to repress the movement of atherosclerosis or its parts by restoring physiological levels of NO. One of the central explanations of the useful capacity of L-arginine broadens the availability of the eNOS substrate, for example, by fighting with unmanufactured dimethylarginine, which is raised under conditions of atherosclerosis as an endogenous agonist inhibitor of eNOS (Chen et al, 2010).. However, exponential measurements will normally be required from 5 to 15 g / day to improve endothelial capacity in sportspersons (Bescos etal, 2012a). 

L-citrulline is a colorless, water-soluble-amino acid which is an intense endogenous precursor of L-arginine. In an ongoing clinical study, the dose of L-citrulline upon dosing would conditionally increase plasma levels of L-arginine in human volunteers, which are more viable than identical L-arginine measurements. In addition, in clinical studies, various analyzers have shown that adding L-citrulline in practice improves blood vessel stiffness, reduces lipoprotein oxidation, lowers blood circulation in the lower leg, and reflects carotid waves and reduces heart rate changes, which is a marker of sudden cardiovascular arrest. Thus, it appears that the addition of L-citrulline has many beneficial effects on the cardiovascular framework of sports personals. (Cemak, Gibala & Van, 2012).

In the present study, a procedure is available to increase the reuse of L-citrulline to L-arginine, which is an important component for controlling the limited accessibility of L-arginine to create NO-catalyzed by eNOS by the synchronous use of L- citrulline and L-arginine was focused. Well-known researchers have found that continued use of both L-citrulline and L-arginine has a superior restorative effect on elevated cholesterol-activated atherosclerosis (Cunnife et al, 2016). However, the transient response to this combination has not yet been investigated. Accordingly, the reason for this study is to evaluate the intense impact of L-citrulline synergy in addition to L-arginine on plasma L-arginine, NO bioavailability and blood flow associated with the NO-cGMP pathway in sports personals (Cunnife et al, 2016).

Benefits of Nitrate and Citrulline

The importance of 1-citrulline as an ergogenic substrate is due to the way 1-citrulline is not subject to a pre-fundamental release and thus could be a more competitive approach to elevating extracellular levels of l-arginine without the entry of any other. L-citrulline malate can produce profitable effects on the end of NH3 during recovery from all-encompassing heavy exercise and, moreover, as a viable precursor to l-arginine and creatine. The nutritional supplement with 1-citrulline alone does not improve the practical performance of sportspersons. The ergogenic response of the 1-citrulline or 1-arginine supplement depends on the condition of the patient’s preparation. Studies involving healthy volunteers have shown that NO benefactors can increase resistance to oxygen and anaerobic exercise (Bond, Morton & Braakhuis, 2012).

L-citrulline is taken to a much greater extent in the intestine by its L-arginine partner and results in a higher plasma level of L-arginine through the arginine/ornithine/citrulline cycle. It is absorbed by a variety of sodium substrates. It was found that oral citrulline supplementation in humans at 0.18 g / kg was found in double plasma arginine that was duplicated somewhere else near an identical increase in ornithine concentrations but these pairs in arginine and ornithine were close to 6- 11 overlapping plasma citrulline (Bond, Morton & Braakhuis, 2012).

A single dose of 6 g of citrulline malate (0.08 g / kg) in precompetitive competitors indicated an increase in plasma citrulline (173% expansion), ornithine (152% expansion) and arginine (123% expansion). Qualities were standardized with 3 hours of rest. The same dose is indicated elsewhere to increase plasma citrulline and arginine to comparable levels.

Strangely, the above-mentioned studies using 0.18 g / kg citrulline noticed an increase in cyclo-triline overlap of six to eleven, close to a minor increase in arginine and ornithine, while later testing using 6 g (calculated at 0.08 g / kg) in citrulline, but dramatically increased both arginine and ornithine. This was also noted in a reaction measurement study using 2 g to 15 g of citrulline, where the citrulline in the plasma is taken directly after dosing, and arginine and ornithine have less confidence in the measurement. Researchers believe that arginine expansion is not as much as expected, and serum citrulline is the main indicator of arginine accumulation, suggesting that its accumulation in kidneys is limiting it’s rate (Bond, Morton & Braakhuis, 2012).

Dietary supplements of l-citrulline malate may increase levels of nitric oxide (NO) metabolites, although this reaction is not identified by a change in atheistic performance. Although a mandatory role in the numerous capabilities of the body that control vasodilation, blood flow, mitochondrial respiration and platelet work is not proven. L-Arginine is a major precursor of NO by the movement of nitric oxide synthase (NOS). In addition, it has been shown that 1-citrulline is a pathway that does NOT give in the NOS subordinate pathway as it can be changed to L-arginine (Bond, Morton & Braakhuis, 2012)..

Study Objective

Research question

This study adopted the following research objective: investigate the effects of nitrate supplementation combined with citrulline on the performance of young healthy cyclists.

Hypothesis

H1: Nitrate supplementation combined with citrulline intake has an effect on the performance of young cyclist.

Null H0: Nitrate supplementation and citrulline have no effect on the performance of cyclist.

The operational definition of terms

Nitrate supplementation- An energy gel compound having an association with greater energy efficiency. Dietary nitrate is found in leafy vegetables and drinking water; they have properties which can be converted to nitric oxide.

Citrulline dose- Citrulline is an amino acid having 175.2 g/mol. It is formed when arginine is converted to nitric oxide.

Cyclist- A Sporting event which involves riding of bicycles.

Young – young adults aged between 18-25 years.

Assumptions

The study assumes that the cyclists will have no medical condition prior to the exercise or factors which enhanced cyclic performance during the administration of the compound.

Also, it will be assumed that all other factors such as eating patterns are kept and constant level to ensure that results obtained are actually the result of nitrate with citrulline supplementation. Nevertheless, it is assumed that the cyclists were not taking any other form of medication prior to this exercise. Further, it is assumed that the participants will abstain from any strenuous exercise and use bacterial mouthwash and chewing gum as they have the ability to impact on the nitric oxide production.  

Limitations

Limitation of this study will entail the inability to control compounding factors in relation to the previous cyclic performance and exercise which ensures long endurance among the cyclist. Further environmental factors which may affect the functioning of the drug such as the effect of sunlight which may accelerate the solution of the drug may not be established.

Delimitations

Exposure to nitrates and nitrites is associated with negative health effects, thus limiting food-containing nitrates, such as spinach, beet, green beans, which can raise the level of nitrate in the body is the main delimitation of this research. Like all fundamental or basic supplements, the adoption of excessive nitrate and nitrite incorporation is associated with the increased risk of negative results. Two types of presentations place vulnerable people in great danger of the antagonistic impact of the introduction of nitrate in abundance. First of all, persons exposed to abundant nitrate in bacterially contaminated wells, which reduces nitrate to nitrite. The second example, where the introduction of nitrates and nitrites is associated with a negative health impact, is through the use of packaged meats. Nitrates added to the meat as preservatives and adding the red color to the meat should be converted to nitrite to implement these activities. The use of nitrates and nitrites in meat products, including bacon, bologna, canned hamburger, meat for lunch and canned meat and hamburger, is subject to restrictions placed by the Food and Drug Administration (FDA). 

Research Hypotheses

Methodology

It is proposed that the study will be undertaken in London city. The study will involve 20 subjects physically active cyclist both male and female gender who will take part in double-blind randomized, placebo-controlled 2way crossover trial. Due to the crossover design, half of the subjects will undergo one condition and the other half undergone another condition in two different days, however, all participants will ingest both treatments over 2 weeks’ time. After intake the treatment compound or the placebo, the participants will be subjected to rests for 1 hour before taking part in the 10km cycling. The cycling time measurements will be performed using cycle ergonometric during the cycling process.

After the enrolment and recruitment of the participants, they will be randomized into two groups in order to receive treatment hours before the actual participation of the cycling exercise in a double-blind technique. 5 capsules containing nitrate supplementation and citrulline compound weighing 2.4 g and 5 capsules of placebo having cornstarch in powder form weighing 2.4 g will be administered.

Time trial test

On the test day after one hour intake of the 2.4 g of the combined compound of nitrate and citrulline or the placebo, each participant will perform time trial test. The rate of the exercise of each participant will be rated at 60 bpm with PWC75%HRmax. The time is taken to complete the 10 km, the concentration of plasma amino acid and lactate level will be determined. Further, the computer trained ergometer system will be recorded at every 10s which these values will be evaluated after every 1 km, in the time trial tests in order to enable the creation of PO profile. Further, in the time trial tests, breath pulmonary gas function will be assessed and measurement of ventilation done using Aero monitor AE-300S tool (breath by breath system).

Wingate test performance

The performance of Wingate test on the participants will be undertaken to measure the peak anaerobic power, capacity and fatigue status. The subjects will operate the arm ergonometric at the full exertion after 30 seconds against the mechanical brake; the test has no resistance to the body weight. Ergonometric will be used to measure the rotations in every 5 seconds. This will yield peak anaerobic power, capacity, and fatigue.

Participants

Randomization of the study participants will be done using statistical software SPSS.

The subjects will have age category of 18-25 years who engage in cyclic activities.

Methodology

The study will exclude participants who are currently on any medication and have injuries, further smokers will be excluded. Further as part of the screening process the participants will be assessed on their health status both physically and through lab examination process. This included the ECG and blood assessment.

Moreover, to assess the levels of activity, the participants will sign statements indicating that they are currently on cycling training of not less than 2 hours daily.

Further all subjects needed to have been participating in cyclic activities and being physically active in the event.

The subjects will be requested not to change their normal dietary or volume intake.

The study will seek ethical approval from the ethics regulation committee at Kingston University of London. Written informed consent will be signed by the participants before undertaking the research process. 

Study design

The study will be conducted in London, UK, where subjects will be randomized into two groups to receive treatment 1 hour before beginning exercise in a double-blind

method, this will entail 5 tablets of a combined form of Nitrate supplementation and citrulline with another dose of a placebo control given to the other participants.

Currently, there are no recommended doses for both citrulline and nitrate supplementation. The subjects will be given the drugs at the same time after breakfast fasting so as to control on confounding factors of food.

Variables

Independent variables to be used in this study entail the level of intensity and burn out experience by the cyclist. Further fatigue levels will be assessed after the 10km cyclic process. Dependent variables are the time taken for burn out to take effect on the participants. Level of burnout will depend on the effect of the treatment compared to the placebo group.

Threats of the validity of the treatment drugs will be managed by having the subjects to have meals at the same time and fast for 4 hours and then administered the treatments and subjected to training. The food is meant to provide the needed energy for drug utilization.

Statistical analysis

Paired t-tests will be used to evaluate significance value of the difference between the treatment group having nitrate supplementation and citrulline compared to those of the placebo group. The paired t-test is useful in measuring the difference between any two sets of data in a given parameter. The measurements are measured twice which yields observation pairs. The advantage of this analytic tool is that the data will be numeric and continuous. This informs the three assumptions which will be applied in this study which are, independence of variables, normal distribution and lack of outliers.

Limitations

The analysis will be performed using SPSS v22. The p value of 0.05 at 95% significance will be used.

Impact of the research

The scientific evidence with regard to use nitrate supplementation with citrulline is limited. There are sufficient studies which attribute nitrate oxide production with

improvement and enhancement in exercises performance and improvements in sporting activities. The study findings will be a milestone in assessing the effects of how the two compounds can have on the performance level.

Currently, many athletes often want to achieve more success and the widespread usage of nutritious foods and sports drinks as well as other ergogenic aids which often require assessment for safe usage and application. The combined effects of nitrate supplementation and citrulline are still largely under-covered and its effects on the exercise performance activities are underscored. This research will bridge the gap and

further elaborate on whether citrulline and nitrate supplementation combination have any significant effects on energy and power in exercise-related activities.

Citrulline supplementation may have positive effects on elevating extracellular activities of amino acids concentration when consumed in combination with other drugs. The nitrate independent pathways exhibited with nitrate oxide synthesis in the body will be assessed, (Camic et al, 2010b). Evidence has suggested that nitrate supplementation has an effect of reducing oxygen perspiration level during exercise, 

hover factors such as exercise duration and intensity can have the impact on the effects, (Bescos et al, 2012b).

Hence the light of these results will have significant uses on improving the level of exercise among cyclists as it deals with high-intensity anaerobic exercise, which may improve post-exercise muscle rest. The usage of these supplements will assess a hypothetical significant benefit that could be an essential effect in intensive sporting activities through lowering of fatigue levels, (Cunniffe et al, 2016).

The overall lack of consensus on the use of dietary supplementation with enhanced substrates such as nitrate supplementation to improve performance is underscored.

Citrulline has not shown conclusive markers of increase of nitrate oxide synthesis or any effects on the physiological responses on the exercise. Hence this study will have significant contributions to the evaluation of their effects on performance, (Giannesini et al, 2011). This will be key in assessing performances of exercise enhancement among varied sporting activities.

The study findings will inform significant action, this will be more crucial in the field of a sports arena, as the findings and protocols followed are of high impact. This makes it applicability more paramount to the general world of sports which is currently rocked by doping and drug enhancing substances. The effects of nitrate supplementation and citrulline amino acid will be key progress in ensuring natural substances are used in performance enhancement in sports.

Conclusion

Furthermore, the process and results of this study will improve my skills and level of competence in laboratory settings and procedures, as well as my confidence and behavior as a researcher, with particular regard to the participant privacy. Results will lead to an acquisition of knowledge of the importance of validity and reliability of the study, also, this project will be geared to enhance my interest in the safe use of activity enhancement substances. 

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