NCT01073332

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

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

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 16 (actual)
• Sponsor: University of California, Los Angeles · Academic / Other
• Sex: All
• Age: 50 Years – 75 Years
• Healthy volunteers: Accepted

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.

Conditions

• Excessive Physical Exercise, Unspecified

Interventions

Type	Name	Description
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.
DIETARY_SUPPLEMENT	Placebo	The placebo group received a powder with all active ingredients replaced with M-100 maltodextrin.

Timeline

• Start date: 2004-10-01
• Primary completion: 2005-02-01
• Completion: 2005-02-01
• First posted: 2010-02-23
• Last updated: 2015-05-08

Locations

1 site across 1 country: United States