Effect of exercise-induced dehydration on circulatory markers of oxidative damage and antioxidant capacity.
Dehydration is a common event associated with exercise. However, few studies have examined the effects of dehydration on plasma redox status in humans. Eighty-two athletes were recruited and baseline anthropometrics and blood samples were obtained. Athletes then engaged in a dehydration protocol, training until 3% of preweight body mass was lost. Athletes returned to the lab and had postdehydration blood collected. Athletes then consumed an isotonic drink until pre-exercise body weight was reestablished. Blood was then recollected (1 h post full rehydration (PFR)). Samples were centrifuged and the plasma snap frozen in liquid nitrogen and stored at -80 °C. Lipid and protein oxidative stress was determined by measuring F2-isoprostanes and protein carbonyls (PC), respectively. Antioxidant capacity was determined by the ferric reducing ability of plasma (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays. Plasma osmolality was determined using an osmometer. Statistical analysis utilized a 1-way ANOVA with posthoc testing. Values are reported as mean ± SD. Plasma osmolality was significantly elevated immediately postdehydration (p ≤ 0.001) but decreased to baseline at PFR. Plasma TEAC increased immediately postdehydration and at PFR (p ≤ 0.001). FRAP increased immediately postdehydration (p ≤ 0.001) and decreased to below baseline at PFR (p ≤ 0.05). Conversely, F2-isoprostanes declined significantly from baseline to immediately postdehydration and then significantly rose at PFR (p ≤ 0.001), whereas PC declined at PFR (p ≤ 0.01). This study indicates that dehydration and exercise cause a significant increase in plasma osmolality and antioxidant potential immediately postexercise. We propose dehydration significantly elevates antioxidant concentration which suppresses F2-isoprostanes and PC.
a Department of Health and Exercise Science, Appalachian State University, 111 Rivers Street, Boone, NC USA.
Vincent P
VP
Georgescu
a Department of Health and Exercise Science, Appalachian State University, 111 Rivers Street, Boone, NC USA.|c Universidade Federal do Parana, Research Group on Metabolism, Nutrition, and Strength Training, Rua Coração de Maria, 92 - BR 116, Curitiba, Brazil.
Tacito P
TP
de Souza Junior
b Department of Nutrition and Health Care Management, Appalachian State University, 261 Locust Street, Boone, NC USA.
Christian
C
Behrens
d Postgraduate program in Human Movement Sciences, Institute of Physical Activity and Sports Sciences (ICAFE), Cruzeiro do Sul University, Rua Coração de Maria, 192 - BR 16 Sao Paulo, Brazil.
Marcelo P
MP
Barros
c Universidade Federal do Parana, Research Group on Metabolism, Nutrition, and Strength Training, Rua Coração de Maria, 92 - BR 116, Curitiba, Brazil.
Carlos Alves
CA
Bueno
a Department of Health and Exercise Science, Appalachian State University, 111 Rivers Street, Boone, NC USA.
Alan C
AC
Utter
b Department of Nutrition and Health Care Management, Appalachian State University, 261 Locust Street, Boone, NC USA.
Lisa S
LS
McAnulty
a Department of Health and Exercise Science, Appalachian State University, 111 Rivers Street, Boone, NC USA.
Steven R
SR
McAnulty
D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D056352:Athletes; D015415:Biomarkers / Q000097:blood*; D001835:Body Weight; D003681:Dehydration / Q000097:blood*; D004492:Edetic Acid / Q000097:blood; D015444:Exercise; D028441:F2-Isoprostanes / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D018384:Oxidative Stress; D050050:Protein Carbonylation; D055815:Young Adult
D000975:Antioxidants; D015415:Biomarkers; D028441:F2-Isoprostanes; D004492:Edetic Acid
antioxidants; antioxydants; dehydration; déshydratation; exercice physique; exercise; humains; humans; oxidative stress; stress oxydatif