Effects of L-arginine and L-citrulline Supplementation on Muscle Respiration

Dietary Exposure Clinical Trial

Official title:

The Effect of L-arginine and L-citrulline Supplementation on Endurance Performance and Mitochondrial Respiration

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03998800
• Other study ID #: R19-P010
• Status: Completed
• Phase: N/A
• Start date: May 1, 2019
• Est. completion date: January 1, 2022

Study information

• Verified date: April 2022
• Source: Loughborough University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 18
• Est. completion date: January 1, 2022
• Est. primary completion date: January 1, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years to 40 Years

Eligibility

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

Related Conditions & MeSH terms

• Dietary Exposure

Intervention

Dietary Supplement:
• Dietary Supplement
Dietary Supplement: L-arginine and L-citrulline supplement, L-arginine supplement, or placebo supplement (corn-starch) Subjects will complete 3 individual 10 day supplementation periods, separated by washout periods of approximately 2 weeks.

Behavioral:
• Endurance exercise on a cycle ergometer
On day 10 of each supplementation period, subjects will complete a performance test on a cycle ergometer to investigate their endurance performance.

Locations

Country	Name	City	State
United Kingdom	School of Sport, Exercise and Health Sciences	Loughborough	Leicester

Sponsors (2)

Lead Sponsor	Collaborator
Loughborough University	Kyowa Hakko Bio Co., Ltd.

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in Endurance performance on a cycle ergometer between L-arginine supplementation and placebo supplementation	On day 10 of the supplementation periods, subjects will complete a performance test on a cycle ergometer to investigate their endurance performance	8-11 weeks
Primary	Change in Endurance performance on a cycle ergometer between L-arginine + L-citrulline supplementation and placebo supplementation	On day 10 of the supplementation periods, subjects will complete a performance test on a cycle ergometer to investigate their endurance performance	8-11 weeks
Primary	Changes of mitochondrial function in skeletal muscle between L-arginine supplementation and placebo supplementation	On day 7 of the supplementation periods, a skeletal muscle biopsy sample will be obtained from subjects to investigate mitochondrial function.	8-11 weeks
Primary	Changes of mitochondrial function in skeletal muscle between L-arginine + L-citrulline supplementation and placebo supplementation	On day 7 of the supplementation periods, a skeletal muscle biopsy sample will be obtained from subjects to investigate mitochondrial function.	8-11 weeks
Secondary	Changes of amino acid and nitric oxide biomarkers levels in plasma between L-arginine supplementation and placebo supplementation	On days 7 and 10 of the supplementation periods, a venous blood sample will be obtained from subjects to investigate amino acid and nitric oxide biomarkers levels in plasma.	8-11 weeks
Secondary	Changes of amino acid and nitric oxide biomarkers levels in plasma between L-arginine + L-citrulline supplementation and placebo supplementation	On days 7 and 10 of the supplementation periods, a venous blood sample will be obtained from subjects to investigate amino acid and nitric oxide biomarkers levels in plasma.	8-11 weeks
Secondary	Changes in muscle oxygenation between L-arginine supplementation and placebo supplementation	On day 10 of the supplementation periods, skeletal muscle oxygenation will be assessed using near-infrared spectroscopy to reveal the tissue saturation index during exercise.	8-11 weeks
Secondary	Changes in muscle oxygenation between L-arginine + L-citrulline supplementation and placebo supplementation	On day 10 of the supplementation periods, skeletal muscle oxygenation will be assessed using near-infrared spectroscopy to reveal the tissue saturation index during exercise.	8-11 weeks
Secondary	Changes in subjective feeling during and after exercise between L-arginine supplementation and placebo supplementation	On day 10 of the supplementation period, subjective feeling during (using the 6-20 ratings of perceived exertion scale) and after (using a 100 mm visual analogue scale where 0 mm = no pain and 100 m = maximal pain) exercise will be assessed. Subjective feeling will also be assessed on the morning of day 11 of each supplementation period.	8-11 weeks
Secondary	Changes in subjective feeling during and after exercise between L-arginine + L-citrulline supplementation and placebo supplementation	On day 10 of the supplementation period, subjective feeling during (using the 6-20 ratings of perceived exertion scale) and after (using a 100 mm visual analogue scale where 0 mm = no pain and 100 m = maximal pain) exercise will be assessed. Subjective feeling will also be assessed on the morning of day 11 of each supplementation period.	8-11 weeks