Exercise-induced oxidative stress before and after vitamin C supplementation.
Vitamin C (ascorbic acid) was supplemented (1 g/day) for 1 day and 2 weeks in the same subjects. Plasma thiobarbituric acid reacting substances (TBARS) and oxygen radical absorbance capacity (ORAC) before and after 30 min submaximal exercise were measured. Different vitamin C supplementations did not affect resting TBARS or ORAC. Following 30 min exercise, values for TBARS were 12.6 and 33% above rest with 1 day and 2 weeks of vitamin C supplementation, respectively, compared to 46% higher with placebo. ORAC did not significantly change (11%) after exercise with a placebo, nor when subjects were given vitamin C supplements for 1 day or 2 days (4.9% and 5.73%, respectively). TBARS:ORAC, a ratio representing oxidative stress, increased 32% (p < .05) with placebo compared to 5.8 and 25.8% with vitamin C supplements for 1 day and 2 weeks, respectively. It was concluded that exercise-induced oxidative stress was highest when subjects did not supplement with vitamin C compared to either 1 day or 2 weeks of vitamin C supplementation.
Alessio
H M
HM
PHS Department, Miami University, Oxford, OH 45056, USA.
Goldfarb
A H
AH
Cao
G
G
D000328:Adult; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000494:pharmacology*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism*
D000975:Antioxidants; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D001205:Ascorbic Acid