Aims and Objectives

The aim of this study is to determine the effects of one week supplementation of L-arginine (ARG) or L-citrulline (CIT) on lactate concentration (LC) during swimming performance, nitric oxide (NO) production, blood flow, blood pressure, plasma insulin and plasma glucose levels compared with a taste- and energy-matched placebo (Pla).

RationaleARG takes part in a number of important methabolic pathways, including NO (Wu et al. 2009). NO modulates blood flow and mitacondrial respiration under physical activity (Shen et al., 1994). Studies shown that when ARG supplementation augments NO biomarkers, exercise capacity are enhanced (Bailey et al., 2010; Shaefer et al., 2002). However, CIT is a remarkable precursor of ARG (Flynn et al. 2002), which is produced as a byproduct end of the NO pathway. CIT is recycled into ARG for next NO shynthesis via the CIT-NO cycle (Haines, Pendleton, and Eichler, 2011). A clinical trial illustrated that orally consuption of CIT dose-dependently augments ARG rate in plasma compared with ARG intake. Howerver, to our knowledge, any study has not investigated the effect of CIT on swimming performance in humans. In swimming, anaerobic threshold (AT) is the most particular factor for swimming in order to illustrate the most important difference from other tests. Hence, particular swimming tests should be used to show any benefits of dietary supplementation in swimmers.

Effect of L-arginine or L-citrulline oral supplementation on blood flow, nitric oxide production and swimming performance in

trained swimmersOzcan ESEN

MethodDay one- Anthropometric measurements (height and weight) will be measured. After that, while the subject is lied down, blood flow and blood pressure will be measured.After that blood samples will be obtained. After all these measurements, participant will apply standardised warm-up (20-25 minutes) and then do 45 minutes pasive recovery. Following the recovery, 5x200m swimming test procedures will be apllied. After swimming test, all measurements will be applied in same prosedure and technique.

ReferencesBailey, S. J., Blackwell, J. R., Lord, T., Vanhatalo, A., Winyard, P. G., & Jones, A. M. (2015). L-citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humans. Journal of Applied Physiology, 119(4), 385-395. Flynn, N.E., Meininger, C.J., Haynes, T.E., Wu, G. (2002) The metabolic basis of arginine nutrition and pharmacotherapy. Biomed Pharmacother, 56, 427–438. Haines, R. J., Pendleton, L. C., & Eichler, D. C. (2011). Argininosuccinate synthase: at the center of arginine metabolism. International journal of biochemistry and molecular biology, 2(1), 8.

Shen, W., Xu, X., Ochoa, M., Zhao, G., Wolin, M. S., & Hintze, T. H. (1994). Role of nitric oxide in the regulation of oxygen consumption in conscious dogs.Circulation Research, 75(6), 1086-1095.

Wu, G., Bazer, F.W., Davis, T.A., Kim, S.W., Li, P., Marc, R.J., Carey, S.M., Smith, S.B., Spencer, T.E., Yin, Y. (2009) Arginine metabolism and nutrition in growth, health and disease. Amino Acids, 37, 153–168

Hypotheses

The following hypotheses are made prior to the commencement of the study. One week supplementation of CIT and ARG will significantly: 1) improve LC during swimming performance, and 2) increase plasma NO poduction, 3) blood flow 4)blood pressure, 5) plasma insulin and 6) decrease plasma glucose.

Data Analysis: Statistical significance will be accepted when p<0.05 and data are

presented as mean±SD. All results of swimming times from swimming tests, blood

samples, blood pressures and blood flow will be collected and assessed by use of

separate Simple One-Way ANOVAs. Tukey test will be used Post Hoc to identify where

significant differences lie.

Diagram 1: Biochemical pathway of NO

Figure 2 and 3: lactate tests

from ear and fingerFigure 1: 5x200 m test protocol

5x200 m swimming test Criterion 1st 2nd 3rd 4th 5th

% of target time 80% 85% 90% 95% 100% target Heart rate below

Maximum -40 -30 -20 -10 10-0

target Times

-20 -15 -10 -5 0

Example (personal best 1.55)

2.20 2.15 2.10 2.05 2.00

Lactate Concentration measurements

1st sample

2nd sample

3rd sample

4th sample

5th sample

Method ContinuesFollowing day one participants will ingest every day over the next 7 days either: a placebo that in pill form or an ARG pill containing 8g ARG or 8g CIT in a double-blind, repeated-measures design. Participants return on the 8th day and will be informed to take 1 more dose supplements 90 minute before swimming test. Following this the same method as day one will be repeated.