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JOURNAL
OF
SPORTS SCIENCE &
MEDICINE
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Research
article
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GRAPE EXTRACT IMPROVES ANTIOXIDANT STATUS AND PHYSICAL PERFORMANCE IN ELITE MALE ATHLETES |
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Sophie Lafay1, Caroline Jan1, Karine Nardon1, Benoit Lemaire1, Alvin Ibarra2  ,
Marc Roller1, Marc Houvenaeghel3, Christine Juhel4
and Louis Cara4 |
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1Naturex SA, Site d'Agroparc, Avignon Cedex 9, France, 2NAT'Life division, Naturex Inc, South Hackensack, NJ, USA, 3Salvator Hospital, Centre Régional de Médecine du Sport, Marseille Cedex 9, France, 4Avantage Nutrition, Luminy Entreprises, Grand Luminy, Marseille, France . |
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© Journal of Sports Science and Medicine (2009) 8, 468 - 480 |
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| ABSTRACT | |||
| Excessive physical exercise overproduces reactive oxygen species.
Even if elite sportsmen increase their antioxidant status by regular physical
training, during the competition period, this improvement is not sufficient
to limit free radical production which could be detrimental to the body.
The aim of this randomized, double-blind, placebo controlled, and crossover
study on 20 elite sportsmen (handball = 10, basketball = 5, sprint = 4,
and volleyball = 1) during the competition period was to determine if the
consumption of a grape extract (GE; Vitis vinifera L.) was able to improve
the parameters related to (i) anti-oxidative status and oxidative stress
and (ii) physical performance. Specific biomarkers of antioxidant capacity,
oxidative stress, skeletal cell muscle damage, and other general biomarkers
were determined in plasma and urine before (D0) and after one month (D30)
of placebo or GE supplementation (400mg·d-1). Effort tests were conducted
using the Optojump® system, which allows determining the total physical
performance (EnRJ45), explosive power (RJ110), and fatigue (RJL5). The plasma
ORAC value was not modified in the placebo group; however, GE increased
the ORAC value compared to the placebo at D30 (14 966+/-335 vs 14 242+/-339
µmol Teq·L-1; p < 0.05). The plasma FRAP value was significantly reduced
in the placebo group, but not in the GE group. Therefore, GE limited the
reduction of FRAP compared to the placebo at D30 (1 053.7+/-31.5 vs 993.7+/-26.7
µmol Teq·L-1; p < 0.05). Urinary isoprostane values were increased in
the placebo group, but were not modified in the GE group. Consequently,
GE limited the production of isoprostanes compared to the placebo at D30
(1.24+/-0.12 vs 1.26+/-0.13 ng·mg-1 creatinine; p < 0.05). GE administration,
compared to the placebo at D30, reduced the plasmatic creatine phosphokinase
concentration (CPK, 695.7+/-177.0 vs 480.0+/-81.1 IU·L-1, p = 0.1) and
increased hemoglobin levels (Hb, 14.5+/-0.2 vs 14.8+/-0.2 vs g·dL-1, p <
0.05), suggesting that GE administration might protect cell damage during
exercise. The high variability between sport disciplines did not permit
to observe the differences in the effort test. Analyzing each individual
group, handball players increased their physical performance by 24% (p <
0.05) and explosive power by 6.4% (p = 0.1) after GE supplementation compared
to the placebo. Further analyses showed that CPK and Hb were the only biomarkers
correlated with the increase in performance. In conclusion, GE ameliorates
the oxidative stress/antioxidant status balance in elite athletes in the
competition period, and enhances performance in one category of sportsmen
(handball). Our results suggest that the enhancement in performance might
be caused by the protective action of GE during physical exercise. These
findings encourage conducting further studies to confirm the efficacy and
mechanisms of action of GE on elite and occasional athletes.
Key words: Botanical extract, oxidative stress, exercise, physiccal performance, sportsmen, training, competition. |
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