The effects of green tea extract supplementation on delayed onset muscle soreness and oxidative stress

Date

2007-08

Journal Title

Journal ISSN

Volume Title

Publisher

Texas Tech University

Abstract

The purpose of this study was to determine whether the antioxidants in green tea reduce biomarkers of oxidative damage and mechanical muscle damage following a downhill endurance run involving repeated eccentric contractions. Subjects were young, healthy males ages 21 – 25 years old free from cardiovascular or musculoskeletal disease whose participation was voluntary. All subjects were currently not taking multivitamins or antioxidant supplements. Subjects reported running 3 – 5 days/week. Foods rich in antioxidants were banned from the subjects’ diets and subjects kept food journals to ensure compliance. Subjects were randomly assigned to the placebo, green tea pre-exercise group, or green tea post-exercise group. The placebo group consumed a placebo before a downhill run and at 5 and 10 hours post-run. The green tea pre-exercise group consumed a green tea extract pill prior to the run and a placebo at 5 and 10 hours post-run. The green tea post-exercise group consumed a placebo pre-exercise and a green tea extract at 5 and 10 hours post-exercise.

Subjects performed an oxygen consumption test on the treadmill in order to establish the exercise intensity of the downhill run. Subjects performed a 45-minute downhill run (-10°) on a treadmill at 60-65% of their VO2peak. Prior to the downhill run, measurements of quadriceps muscle soreness, isometric force production, range of motion, and thigh circumference was obtained. A blood draw was taken pre-exercise and post-exercise. Subjects returned to the lab 24-hours post exercise for a final blood draw and measurements of quadriceps muscle soreness, isometric force production, range of motion, and thigh circumference.

Blood samples were analyzed for creatine kinase (muscle damage) and malondialdehyde (oxidative stress). Creatine kinase levels were significantly elevated at 24 hours post-exercise (P

Description

Keywords

Green tea extract, Muscle soreness, Oxidative stress

Citation