Researchers at the David Geffen School of Medicine at UCLA, in Los Angeles, California, studied the effects of arginine + antioxidants on exercise performance in older people.
First, the details.
- 16 elderly male cyclists were randomly assigned to a treatment group for 3 weeks.
- A proprietary supplement (Niteworks, Herbalife International Inc.)
- A placebo powder
- Exercise parameters were assessed by maximal incremental exercise testing performed on a stationary cycle ergometer using breath-by-breath analysis at the start and weeks 1 and 3.
- Neither the patients nor researchers knew the treatment given — double blind.
And, the results.
- In the Niteworks group, anaerobic threshold significantly increased 17% at week 1, and the effect was significantly sustained by week 3.
- In the placebo group, there was no change in anaerobic threshold.
- The anaerobic threshold for the Niteworks group was significantly higher vs placebo at week 1 and week 3.
- There were no significant changes in VO2 max (a measure of aerobic capacity) between placebo and Niteworks groups at either week 1 or 3 when compared to the start of the study.
- There were no side effects in either group.
The bottom line?
The authors concluded, “An arginine and antioxidant-containing supplement increased the anaerobic threshold at both week one and week three in elderly cyclists. No effect on VO2 max was observed. This study indicated a potential role of L-arginine and antioxidant supplementation in improving exercise performance in elderly.”
It’s not stated in the study whether aside from positive changes in anaerobic threshold there were clinically meaningful benefits. Does a 17% change result in better quality of life, greater activities of daily living, etc.?
More background on arginine and exercise performance is here.
NOTE: The study, conducted at UCLA and funded by Herbalife, used Herbalife’s original formula Niteworks. The current product has a slightly different formula, although no changes were made to the active ingredients, according to the article published on Medical News Today.
4/11/10 20:31 JR