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

Not Applicable

Completed

• Conditions: Excessive Physical Exercise, Unspecified
• Interventions: Dietary Supplement: Arginine antioxidant supplements; Dietary Supplement: Placebo

• Registration Number: NCT01073332
• Lead Sponsor: University of California, Los Angeles

Brief 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.

Detailed 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.

Study Timeline

• Study Start: 2004-10
• Primary Completion: 2005-02
• Study Completion: 2005-02
• Status Verified: 2010-02
• Study First Submitted: 2010-02-22
• Study First Submitted QC: 2010-02-22
• Study First Posted: 2010-02-23
• Last Update Submitted: 2015-05-06
• Last Update Posted: 2015-05-08

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 16

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

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Arginine antioxidant supplements	Arginine antioxidant supplements	Dietary Supplement: Niteworks
Placebo	Placebo	The placebo group received a powder with all active ingredients replaced with M-100 maltodextrin.

Primary Outcome Measures

Name	Time	Method
Arginine and antioxidant supplements, as compared with placebo will improve exercise performance	3 weeks

Secondary Outcome Measures

Name	Time	Method
Arginine and antioxidant Supplements improve maximal oxygen uptake and anaerobic threshold	3 weeks

Trial Locations

Locations (1)

University of California, Los Angeles; 🇺🇸 Los Angeles, California, United States