Effect of 1 Repetition Maximum, 80% Repetition Maximum, and 50% Repetition Maximum Strength Exercise in Trained Individuals on Variations in Plasma Redox Biomarkers.
Polotow, TG, Souza-Junior, TP, Sampaio, RC, Okuyama, AR, Ganini, D, Vardaris, CV, Alves, RC, McAnulty, SR, and Barros, MP. Effect of 1RM, 80%RM, and 50%RM strength exercise in trained individuals on variations in plasma redox biomarkers. J Strength Cond Res 31(9): 2489-2497, 2017-For decades, scientists have examined the participation of oxygen/nitrogen species in anaerobic-like exercises, especially weightlifting and resistance exercises. The balance between the production of oxyradicals and antioxidant responses during anaerobic-like exercises is essential to assure adaptation to the physiological benefits of strength training and to prevent chronic harmful effects. The aim of this study is to examine the hypothesis that different weight loads (1 repetition maximum (RM), 80%RM, and 50%RM) lifted until exhaustion could impose distinct oxidative insults and elicit diverse antioxidant responses in plasma of young trained subjects. Glucose (+10%), lactate (+65%), urea (+30%), free iron (+65%), reduced/oxidized glutathione (+14 and +23%, respectively), and xanthine oxidase activity (2.2-fold) significantly increased after the 1RM test, whereas plasma antioxidant capacity dropped by 37%. When lower weight loads were applied (80%RM and 50%RM tests), heme-iron (+15 and +20%, respectively) became the prevalent pro-oxidant, although glutathione responses were only detected after 80%RM (+14%). Lactate concentration in plasma continuously increased, by 2.9-fold (80%RM) and 3.6-fold higher (50%RM test). We demonstrated that 1RM tests significantly diminish the antioxidant capacity of plasma because of iron overload, whereas 80%RM tests require higher involvement of glutathione molecules to counteract heme-iron oxidative insult. Mild redox imbalances promoted by heme-iron were found in plasma after 50%RM. Although we did not observe overall changes in muscle damage in young trained subjects, we cannot exclude the need for specific antioxidant supplementation depending on the strength protocols applied, especially for less responsive groups, such as sedentary and elderly populations.
1Institute of Physical Activity and Sports Science (ICAFE), Cruzeiro do Sul University, São Paulo, Brazil; 2Department of Physical Education, Research Group on Metabolism, Nutrition and Strength Training, Federal University of Parana, Curitiba, Brazil; 3Department of Health and Exercise Science, Appalachian State University, Boone, North Carolina; and 4Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina.
Tatiana G
TG
Polotow
Tácito P
TP
Souza-Junior
Ricardo C
RC
Sampaio
Alexandre R
AR
Okuyama
Douglas
D
Ganini
Cristina V
CV
Vardaris
Ragami C
RC
Alves
Steven R
SR
McAnulty
Marcelo P
MP
Barros
D000328:Adult; D015415:Biomarkers; D001786:Blood Glucose; D015444:Exercise / Q000502:physiology; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism*; D055070:Resistance Training / Q000379:methods*; D014508:Urea / Q000097:blood; D014969:Xanthine Oxidase / Q000097:blood; D055815:Young Adult
D015415:Biomarkers; D001786:Blood Glucose; D017382:Reactive Oxygen Species; D019344:Lactic Acid; D014508:Urea; D014969:Xanthine Oxidase; D005978:Glutathione