| Full text | |
| Author(s): |
Barros, Marcelo P.
[1]
;
Ganini, Douglas
[2]
;
Lorenco-Lima, Leandro
[1]
;
Soares, Chrislaine O.
[2]
;
Pereira, Benedito
[3]
;
Bechara, Etelvino J. H.
[2, 4]
;
Silveira, Leonardo R.
[5]
;
Curi, Rui
[6]
;
Souza-Junior, Tacito P.
[7]
Total Authors: 9
|
| Affiliation: | [1] Univ Cruzeiro Sul, Inst Phys Activ & Sports Sci ICAFE, Postgrad Program Human Movement Sci, BR-01506000 Sao Paulo - Brazil
[2] Univ Sao Paulo, Dept Biochem, BR-05508900 Sao Paulo - Brazil
[3] Univ Sao Paulo, Sch Phys Educ & Sports, BR-05508900 Sao Paulo - Brazil
[4] Univ Fed Sao Paulo, UNIFESP, BR-09972270 Diadema - Brazil
[5] Univ Sao Paulo USP RP, Sch Phys Educ & Sports, BR-05508900 Ribeirao Preto - Brazil
[6] Univ Sao Paulo, Dept Physiol & Biophys, BR-05508900 Sao Paulo, SP - Brazil
[7] Univ Fed Parana, Dept Phys Educ, BR-80215370 Curitiba, Parana - Brazil
Total Affiliations: 7
|
| Document type: | Journal article |
| Source: | JOURNAL OF THE INTERNATIONAL SOCIETY OF SPORTS NUTRITION; v. 9, JUN 12 2012. |
| Web of Science Citations: | 7 |
| Abstract | |
Background: Dietary creatine has been largely used as an ergogenic aid to improve strength and athletic performance, especially in short-term and high energy-demanding anaerobic exercise. Recent findings have also suggested a possible antioxidant role for creatine in muscle tissues during exercise. Here we evaluate the effects of a 1-week regimen of 20 g/day creatine supplementation on the plasma antioxidant capacity, free and heme iron content, and uric acid and lipid peroxidation levels of young subjects (23.1 +/- 5.8 years old) immediately before and 5 and 60 min after the exhaustive Wingate test. Results: Maximum anaerobic power was improved by acute creatine supplementation (10.5 %), but it was accompanied by a 2.4-fold increase in pro-oxidant free iron ions in the plasma. However, potential iron-driven oxidative insult was adequately counterbalanced by proportional increases in antioxidant ferric-reducing activity in plasma (FRAP), leading to unaltered lipid peroxidation levels. Interestingly, the FRAP index, found to be highly dependent on uric acid levels in the placebo group, also had an additional contribution from other circulating metabolites in creatine-fed subjects. Conclusions: Our data suggest that acute creatine supplementation improved the anaerobic performance of athletes and limited short-term oxidative insults, since creatine-induced iron overload was efficiently circumvented by acquired FRAP capacity attributed to: overproduction of uric acid in energy-depleted muscles (as an end-product of purine metabolism and a powerful iron chelating agent) and inherent antioxidant activity of creatine. (AU) | |