Table 3.  Body weight, plasma and urinary parameters, and relative values of effort test, before (D0) and after (D30) supplementation of GE or placebo in elite sportsmen. Values are means (± SEM) of 20 determinations performed in duplicate on samples from different subjects; n = 20 elite sportsmen.
 
Placebo n=20
Grape extract n=20
 
D0
D30
D0
D30

Weight (kg)
84.4 (3.1)
83.7 (2.9)
84.8 (3.1)
84.0 ( 3.1)

Biomarkers of antioxidant status and oxidative stress

ORAC (µmol·L-1)
14 488 (380)
14 242 (339)
13 885 (360)
14 966 (335) *#

FRAP (µmol·L-1 Fe2+)
1 084 (43)
994 (27) *
1 071 (32)
1 054 (32) #

LDLox (mU·mL-1)
481 (98)
473 (106)
556 (119)
576 (128)

SOD (U·g-1 Hb)
2 368 (85)
2 438 (77)
2 523 (105)
2 541 (92)

GPx (µmol·min-1·g -1 Hb)
17.1 (1.0)
15.1 (.9) *
18.9 (1.1)
17.4 (.9) #

Catalase (mol·min-1.g -1 Hb)
.625 (.039)
.560 (.051)
.653 (.030)
.673 (.057)

Vitamin E (µg·mL-1)
12.49 (.36)
12.50 (.46)
12.79 (.49)
13.15 (.41) #

Vit E/cholesterol ratio (µg·mg-1)
6.74 (.20)
6.97 (.20)
6.99 (.21)
7.24 (.25) #

Vit C (µmol·L-1)
62.8 (4.9)
57.6 (4.6)
55.8 (3.2)
54.5 (4.3)

Isoprostanes (ng·mg-1 creatinine)
1.18 (.11)
1.64 (.18) *
1.24 (.12)
1.26 (.13) #

Biomarker of skeletal muscle damage

Creatine phosphokinase (UI·L-1)
529 (122)
696 (177)
605 (158)
480 (81)

General plasmatic biomarkers

Triglycerides (g·L-1)
.54 (.05)
.58 (.06)
.59 (.07)
.68 (.10)

Cholesterol (g·L-1)
1.87 (.05)
1.81 (.05)
1.84 (.06)
1.85 (.05)

Ferritin (µg·L-1)
76.9 (9.7)
69.2 (9.3) *
79.0 (10.9)
69.8 (10.8) *

Urea (g·L-1)
.287 (.012)
.279 (.013)
.301 (.013)
.291 (.019)

Hemoglobin (g·dL-1)
14.7 (.1)
14.5 (.2)
14.5 (.2)
14.8 (.2) *#

Effort test

Performance (EnRJ45, %)
-.47 (3.77)
4.59 (5.99)

Explosive power (RJ110, %)
-1.53 (1.92)
.73 (2.65)

Fatigue (RJ5, %)

1.64 (3.22)
9.55 (5.34)
* Significantly different from the pre-treatment (D0); p < 0.05 (paired t test). # Significantly different from the placebo post-treatment (D30); p < 0.05 (paired t test).