Clinical trial NCT03998800: Effects of L-arginine and L-citrulline Supplementation on Muscle Respiration
Official title: The Effect of L-arginine and L-citrulline Supplementation on Endurance Performance and Mitochondrial Respiration
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Dietary Exposure
Keywords: Endurance performance
Mitochondrial function
L-arginine
L-citrulline
Healthy males
Lead sponsor: Loughborough University
Sponsor class: OTHER
Collaborators: name: Kyowa Hakko Bio Co., Ltd.
First posted: 2019-06-26
Enrollment: 18
Sex: MALE
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Allocation: Randomized Endpoint Classification: Efficacy Study Intervention Model: Crossover Assignment Masking: Double Blind (Subject, Investigator)
Primary purpose: BASIC_SCIENCE

Brief summary: The objective of this trial is to determine the effects of dietary supplementation with the amino acids, L-arginine and L-citrulline, on endurance performance and mitochondrial respiration in healthy men compared to supplementation with L-arginine alone and a placebo supplement.

Detailed description: This study is a randomized, double-blind, cross over trial of L-arginine and L-citrulline supplementation, L-arginine supplementation alone and placebo supplementation in healthy men. The intervention period will be 8-11 weeks for each participant and a minimum of 15 individuals will be recruited and enrolled to complete the trial. Subjects will complete the experimental protocol described below over 3 individual 10 day supplementation periods, separated by washout periods of approximately 2 weeks. Subjects will ingest corn-starch as a placebo, L-arginine (3g/day) or L-arginine (1.5 g/day) + L-citrulline (1.5g/day). On day 7 of the supplementation period, a skeletal muscle biopsy and blood sample will be obtained from the subjects to investigate mitochondrial function and blood amino acid and nitric oxide levels. On day 10 of the supplementation period, subjects will complete a performance test on a cycle ergometer to investigate their endurance performance. These assessments will be performed to determine the effects of co-ingesting L-arginine and L-citrulline compared to L-arginine alone and placebo administration.

Eligibility criteria: Inclusion Criteria:

* healthy male, 18-40 years of age
* recreationally-active
* healthy BMI (≥18.5 and ≤24.9 kg/m2)

Exclusion Criteria:

* participating in other studies currently or in the past two months or has an intention to participate in other studies over the period of this study
* history of gastric, digestive, cardiovascular, renal disease or any other orthopaedic diseases related to motor organs
* lidocaine allergy
* use of medication that may affect study measures
* contraindication to the biopsy procedures
* on medications that affect the immune system
* on Aspirin or other drugs known to prolong bleeding
* smoker
* user of dietary supplements currently or in the past one month
* a heavy drinker

Primary outcomes:
measure: Change in Endurance performance on a cycle ergometer between L-arginine supplementation and placebo supplementation
timeFrame: 8-11 weeks
measure: Change in Endurance performance on a cycle ergometer between L-arginine + L-citrulline supplementation and placebo supplementation
timeFrame: 8-11 weeks
measure: Changes of mitochondrial function in skeletal muscle between L-arginine supplementation and placebo supplementation
timeFrame: 8-11 weeks
measure: Changes of mitochondrial function in skeletal muscle between L-arginine + L-citrulline supplementation and placebo supplementation
timeFrame: 8-11 weeks
Secondary outcomes:
measure: Changes of amino acid and nitric oxide biomarkers levels in plasma between L-arginine supplementation and placebo supplementation
timeFrame: 8-11 weeks
measure: Changes of amino acid and nitric oxide biomarkers levels in plasma between L-arginine + L-citrulline supplementation and placebo supplementation
timeFrame: 8-11 weeks
measure: Changes in muscle oxygenation between L-arginine supplementation and placebo supplementation
timeFrame: 8-11 weeks
measure: Changes in muscle oxygenation between L-arginine + L-citrulline supplementation and placebo supplementation
timeFrame: 8-11 weeks
measure: Changes in subjective feeling during and after exercise between L-arginine supplementation and placebo supplementation
timeFrame: 8-11 weeks
measure: Changes in subjective feeling during and after exercise between L-arginine + L-citrulline supplementation and placebo supplementation
timeFrame: 8-11 weeks
Other outcomes:
Locations:
city: Loughborough
country: United Kingdom
facility: School of Sport, Exercise and Health Sciences
state: Leicester
Study officials:
affiliation: Lecturer
name: Stephen J Bailey, PhD
role: PRINCIPAL_INVESTIGATOR
References: