Effect of a single dose of green tea polyphenols on the blood markers of exercise-induced oxidative stress in soccer players.
OBJECTIVE
To evaluate the effect of acute ingestion of green tea polyphenols (GTP) on blood markers of oxidative stress and muscle damage in soccer players exposed to intense exercise.


METHODS
This randomized, double-blinded study was conducted on 16 players during a general preparation period, when all athletes participated in a strength-training program focused on the development of strength endurance. After ingestion of a single dose of GTP (640 mg) or placebo, all athletes performed an intense muscle-endurance test consisting of 3 sets of 2 strength exercises (bench press, back squat) performed to exhaustion, with a load at 60% 1-repetition maximum and 1-min rests between sets. Blood samples were collected preexercise, 5 min after the muscle-endurance test, and after 24 hr of recovery. Blood plasma was analyzed for the concentrations of thiobarbituric acid-reacting substances (TBARS), uric acid (UA), total catechins, total antioxidant status (TAS), and activity of creatine kinase (CK); at the same time, erythrocytes were assayed for the activity of superoxide dismutase (SOD).


RESULTS
In both groups, plasma TBARS, UA, and TAS increased significantly postexercise and remained elevated after a 24-hr recovery period. SOD activity in erythrocytes did not change significantly in response to the muscle-endurance test, whereas in both groups plasma CK activity increased significantly after 24 hr of recovery. Acute intake of GTP cased a slight but significant increase in total plasma catechins. However, GTP was found not to exert a significant effect on measured parameters.


CONCLUSIONS
Acute ingestion of GTP (640 mg) does not attenuate exercise-induced oxidative stress and muscle damage.
Faculty of Physical Education and Sport in Biala Podlaska, University of Physical Education, Warsaw, Poland.
Ewa
E
Jówko
Jaroslaw
J
Sacharuk
Bozena
B
Balasinska
Jacek
J
Wilczak
Malgorzata
M
Charmas
Piotr
P
Ostaszewski
Robert
R
Charmas
D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000032:analysis / Q000737:chemistry / Q000627:therapeutic use*; D056352:Athletes; D015415:Biomarkers / Q000097:blood; D028241:Camellia sinensis / Q000737:chemistry*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005419:Flavonoids / Q000032:analysis / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D009220:Myositis / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D018384:Oxidative Stress; D005082:Physical Exertion; D010936:Plant Extracts / Q000737:chemistry / Q000627:therapeutic use; D018515:Plant Leaves / Q000737:chemistry; D011044:Poland; D059808:Polyphenols / Q000032:analysis / Q000097:blood / Q000627:therapeutic use; D012916:Soccer; D064133:Sports Nutritional Physiological Phenomena; D055815:Young Adult
D000975:Antioxidants; D015415:Biomarkers; D005419:Flavonoids; D010936:Plant Extracts; D059808:Polyphenols