The Effects of a Dietary Supplement on Exercise Performance in Healthy Older Adults"

Excessive Physical Exercise, Unspecified Clinical Trial

Official title:

Arginine and Antioxidant Supplement on Performance in Elderly Male Cyclists: A Randomized Controlled Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01073332
• Other study ID #: UCLA_IRB_03-08-087-01
• Status: Completed
• Phase: N/A
• First received: February 22, 2010
• Last updated: May 6, 2015
• Start date: October 2004
• Est. completion date: February 2005

Study information

• Verified date: February 2010
• Source: University of California, Los Angeles
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

Human exercise capacity decreases with aging. One explanation may be that blood vessels stiffen with age and release less of a compound called nitric oxide (NO). This compound normally relaxes blood vessels and increases blood flow to muscles, but damaging compounds called free radicals can interfere with this process. Antioxidants may help prevent free radicals from inactivating nitric oxide. The purpose of this study was to investigate the effects of an antioxidant supplement that supports NO production on exercise performance in elderly male cyclists.

Description:

Since the discovery of the vascular smooth muscle relaxant properties of nitric oxide (NO) over 25 years ago, studies have implicated this molecule in modulating such processes as atherosclerosis, impotence, angina, platelet function, and blood pressure, among others. Through vascular smooth muscle relaxation in both coronary and skeletal muscle arteries, as well as via independent mechanisms, nitric oxide has also been implicated in improvement of exercise capacity. In addition, NO may be involved in the immune system, assist in memory function and sleep regulation, and act as a cellular signaling messenger. Youthful, healthy and athletic individuals generally have a healthier NO system, compared to sedentary, unhealthy and aging individuals. NiteworksTM is a dietary supplement that includes L-arginine, an amino acid that acts as a nitric oxide donor and has been shown to increase levels of this molecule in the body. NiteworksTM has been formulated as a composite mixture along with other supplements, including antioxidants, that may act synergistically with L-arginine in enhancing exercise capacity.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 16
• Est. completion date: February 2005
• Est. primary completion date: February 2005
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 50 Years to 75 Years

Eligibility

Inclusion Criteria:

• Males and females

• Age 50-75 years, inclusive

• Ability to perform pulmonary function and exercise tests

• Willingness to take supplement powder for 3 weeks

• Ethical: Subject must sign the Institutional Review Board-approved written informed consent prior to he initiation of any study specific procedures or randomization. A subject will be excluded for any condition that might compromise the ability to give truly informed consent for participation in the study.

Exclusion Criteria:

• Existing pulmonary or cardiovascular disease

• Previous cardiac surgery

• Not able to tolerate breathing through mouthpiece for up to 20 minutes

• Musculoskeletal disease that would limit exercise

Study Design

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Excessive Physical Exercise, Unspecified

Intervention

Dietary Supplement:
• Arginine antioxidant supplements
The proprietary supplement Niteworks® was manufactured by Herbalife International Inc. (Century City, California, USA). Each serving contained 5.2g L-arginine in a proprietary blend with L-citrulline, 500mg ascorbic acid, 400IU vitamin E, 400ug folic acid, 300mg L-taurine, and 10mg alpha lipoic acid in a lemon-flavored powder form. One serving of supplement powder was mixed with 8 oz of water, administered at bedtime based on the rationale that nitric oxide levels are lowest during sleep due to inactivity, lack of food and low blood pressure.
• Placebo
The placebo group received a powder with all active ingredients replaced with M-100 maltodextrin.

Locations

Country	Name	City	State
United States	University of California, Los Angeles	Los Angeles	California

Sponsors (1)

Lead Sponsor	Collaborator
University of California, Los Angeles

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Arginine and antioxidant supplements, as compared with placebo will improve exercise performance		3 weeks	No
Secondary	Arginine and antioxidant Supplements improve maximal oxygen uptake and anaerobic threshold		3 weeks	No