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Prior exercise and antioxidant supplementation: effect on oxidative stress and muscle injury.

Bloomer RJ, Falvo MJ, Schilling BK, Smith WA - J Int Soc Sports Nutr (2007)

Bottom Line: However, most studies have focused on untrained participants rather than on athletes.No group by time interactions were noted for any variable (P > 0.05).Time main effects were noted for creatine kinase activity, muscle soreness, maximal isometric force and peak velocity (P < 0.0001).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Health and Sport Sciences, University of Memphis, Memphis, TN, USA. rbloomer@memphis.edu.

ABSTRACT

Background: Both acute bouts of prior exercise (preconditioning) and antioxidant nutrients have been used in an attempt to attenuate muscle injury or oxidative stress in response to resistance exercise. However, most studies have focused on untrained participants rather than on athletes. The purpose of this work was to determine the independent and combined effects of antioxidant supplementation (vitamin C + mixed tocopherols/tocotrienols) and prior eccentric exercise in attenuating markers of skeletal muscle injury and oxidative stress in resistance trained men.

Methods: Thirty-six men were randomly assigned to: no prior exercise + placebo; no prior exercise + antioxidant; prior exercise + placebo; prior exercise + antioxidant. Markers of muscle/cell injury (muscle performance, muscle soreness, C-reactive protein, and creatine kinase activity), as well as oxidative stress (blood protein carbonyls and peroxides), were measured before and through 48 hours of exercise recovery.

Results: No group by time interactions were noted for any variable (P > 0.05). Time main effects were noted for creatine kinase activity, muscle soreness, maximal isometric force and peak velocity (P < 0.0001). Protein carbonyls and peroxides were relatively unaffected by exercise.

Conclusion: There appears to be no independent or combined effect of a prior bout of eccentric exercise or antioxidant supplementation as used here on markers of muscle injury in resistance trained men. Moreover, eccentric exercise as used in the present study results in minimal blood oxidative stress in resistance trained men. Hence, antioxidant supplementation for the purpose of minimizing blood oxidative stress in relation to eccentric exercise appears unnecessary in this population.

No MeSH data available.


Related in: MedlinePlus

Muscle soreness (A), maximal isometric force (B), peak velocity (C), and maximal dynamic force (D) before and following an acute bout of eccentric resistance exercise in trained men. No prior exercise + placebo (NoP); no prior exercise + antioxidant (NoA); prior exercise + placebo (ExP); prior exercise + antioxidant (ExA). No significant group differences noted for any variables (P > 0.05). Time main effects were noted for muscle soreness, maximal isometric force, and peak velocity (P < 0.0001).
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Figure 2: Muscle soreness (A), maximal isometric force (B), peak velocity (C), and maximal dynamic force (D) before and following an acute bout of eccentric resistance exercise in trained men. No prior exercise + placebo (NoP); no prior exercise + antioxidant (NoA); prior exercise + placebo (ExP); prior exercise + antioxidant (ExA). No significant group differences noted for any variables (P > 0.05). Time main effects were noted for muscle soreness, maximal isometric force, and peak velocity (P < 0.0001).

Mentions: A time main effect was noted for muscle soreness (P < 0.0001) with values peaking 24 hours post exercise (5.9 ± 0.3/10-point scale), and elevated above pre exercise at all times post exercise (P < 0.05). No interaction effect was noted for muscle soreness (P = 0.324). Muscle soreness was significantly correlated to creatine kinase activity (r = 0.288, P < 0.0001), but the relationship is weak. Baseline muscle performance variables were not different between groups (P > 0.05). Time main effects were also noted for maximal isometric force and peak velocity (P < 0.0001), with lower values immediately and 24 hours post exercise compared to pre exercise (P < 0.05). Values remained below pre exercise at 48 hours post exercise for maximal isometric force but recovered by 24 hours post exercise for peak velocity. The pattern of change for these variables was not different between groups, evidenced by insignificant interaction effects for both isometric force (P = 0.742) and peak velocity (P = 0.847). Peak dynamic force was decreased slightly immediately post exercise, but insignificantly (P = 0.082), and recovered to pre exercise values by 24 hours post exercise. No interaction effect was noted for peak dynamic force (P = 0.563). Data for muscle soreness and function are shown in Figure 2.


Prior exercise and antioxidant supplementation: effect on oxidative stress and muscle injury.

Bloomer RJ, Falvo MJ, Schilling BK, Smith WA - J Int Soc Sports Nutr (2007)

Muscle soreness (A), maximal isometric force (B), peak velocity (C), and maximal dynamic force (D) before and following an acute bout of eccentric resistance exercise in trained men. No prior exercise + placebo (NoP); no prior exercise + antioxidant (NoA); prior exercise + placebo (ExP); prior exercise + antioxidant (ExA). No significant group differences noted for any variables (P > 0.05). Time main effects were noted for muscle soreness, maximal isometric force, and peak velocity (P < 0.0001).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2131751&req=5

Figure 2: Muscle soreness (A), maximal isometric force (B), peak velocity (C), and maximal dynamic force (D) before and following an acute bout of eccentric resistance exercise in trained men. No prior exercise + placebo (NoP); no prior exercise + antioxidant (NoA); prior exercise + placebo (ExP); prior exercise + antioxidant (ExA). No significant group differences noted for any variables (P > 0.05). Time main effects were noted for muscle soreness, maximal isometric force, and peak velocity (P < 0.0001).
Mentions: A time main effect was noted for muscle soreness (P < 0.0001) with values peaking 24 hours post exercise (5.9 ± 0.3/10-point scale), and elevated above pre exercise at all times post exercise (P < 0.05). No interaction effect was noted for muscle soreness (P = 0.324). Muscle soreness was significantly correlated to creatine kinase activity (r = 0.288, P < 0.0001), but the relationship is weak. Baseline muscle performance variables were not different between groups (P > 0.05). Time main effects were also noted for maximal isometric force and peak velocity (P < 0.0001), with lower values immediately and 24 hours post exercise compared to pre exercise (P < 0.05). Values remained below pre exercise at 48 hours post exercise for maximal isometric force but recovered by 24 hours post exercise for peak velocity. The pattern of change for these variables was not different between groups, evidenced by insignificant interaction effects for both isometric force (P = 0.742) and peak velocity (P = 0.847). Peak dynamic force was decreased slightly immediately post exercise, but insignificantly (P = 0.082), and recovered to pre exercise values by 24 hours post exercise. No interaction effect was noted for peak dynamic force (P = 0.563). Data for muscle soreness and function are shown in Figure 2.

Bottom Line: However, most studies have focused on untrained participants rather than on athletes.No group by time interactions were noted for any variable (P > 0.05).Time main effects were noted for creatine kinase activity, muscle soreness, maximal isometric force and peak velocity (P < 0.0001).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Health and Sport Sciences, University of Memphis, Memphis, TN, USA. rbloomer@memphis.edu.

ABSTRACT

Background: Both acute bouts of prior exercise (preconditioning) and antioxidant nutrients have been used in an attempt to attenuate muscle injury or oxidative stress in response to resistance exercise. However, most studies have focused on untrained participants rather than on athletes. The purpose of this work was to determine the independent and combined effects of antioxidant supplementation (vitamin C + mixed tocopherols/tocotrienols) and prior eccentric exercise in attenuating markers of skeletal muscle injury and oxidative stress in resistance trained men.

Methods: Thirty-six men were randomly assigned to: no prior exercise + placebo; no prior exercise + antioxidant; prior exercise + placebo; prior exercise + antioxidant. Markers of muscle/cell injury (muscle performance, muscle soreness, C-reactive protein, and creatine kinase activity), as well as oxidative stress (blood protein carbonyls and peroxides), were measured before and through 48 hours of exercise recovery.

Results: No group by time interactions were noted for any variable (P > 0.05). Time main effects were noted for creatine kinase activity, muscle soreness, maximal isometric force and peak velocity (P < 0.0001). Protein carbonyls and peroxides were relatively unaffected by exercise.

Conclusion: There appears to be no independent or combined effect of a prior bout of eccentric exercise or antioxidant supplementation as used here on markers of muscle injury in resistance trained men. Moreover, eccentric exercise as used in the present study results in minimal blood oxidative stress in resistance trained men. Hence, antioxidant supplementation for the purpose of minimizing blood oxidative stress in relation to eccentric exercise appears unnecessary in this population.

No MeSH data available.


Related in: MedlinePlus