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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

Creatine kinase activity (A), C-reactive protein (B), protein carbonyls (C) and peroxides (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). A time main effect was noted only for creatine kinase activity (P < 0.0001).
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Figure 1: Creatine kinase activity (A), C-reactive protein (B), protein carbonyls (C) and peroxides (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). A time main effect was noted only for creatine kinase activity (P < 0.0001).

Mentions: A time main effect was noted for creatine kinase activity (P < 0.0001) with values collectively peaking at 24 hours post exercise (317 ± 29U·L-1) compared to pre exercise (139 ± 29U·L-1). Creatine kinase activity was significantly higher than pre exercise at 24 and 48 hours post exercise (P < 0.05). Creatine kinase activity appeared lower in the prior exercise groups, however no statistical interaction was noted (P = 0.252). C-reactive protein was not different between groups (P = 0.091) and collectively was elevated to the greatest extent at 24 hours post exercise with no time main effect noted (P > 0.05). Neither creatine kinase activity nor C-reactive protein followed a normal distribution and therefore, data were log transformed prior to analysis. However, for ease of comparison to other published studies using these biomarkers, the original values are included in Figure 1. Pre exercise antioxidant reducing capacity was not different (P = 0.422) between NoP, NoA, ExP, or ExA (0.206 ± 0.067; 0.265 ± 0.071, 0.336 ± 0.077; 0.354 ± 0.063 mmol·L-1), respectively. Protein carbonyls were not statistically different between groups (P = 0.351), but experienced a peak from pre to 24–48 hours post exercise that failed to reach significance (P = 0.152). Creatine kinase activity was correlated to both protein carbonyls (r = 0.391, P < 0.00001) and C-reactive protein (r = 0.403, P < 0.00001). No statistical main effects or interaction were noted for peroxides (P > 0.05). Data for bloodborne variables are shown in Figure 1.


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)

Creatine kinase activity (A), C-reactive protein (B), protein carbonyls (C) and peroxides (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). A time main effect was noted only for creatine kinase activity (P < 0.0001).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Creatine kinase activity (A), C-reactive protein (B), protein carbonyls (C) and peroxides (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). A time main effect was noted only for creatine kinase activity (P < 0.0001).
Mentions: A time main effect was noted for creatine kinase activity (P < 0.0001) with values collectively peaking at 24 hours post exercise (317 ± 29U·L-1) compared to pre exercise (139 ± 29U·L-1). Creatine kinase activity was significantly higher than pre exercise at 24 and 48 hours post exercise (P < 0.05). Creatine kinase activity appeared lower in the prior exercise groups, however no statistical interaction was noted (P = 0.252). C-reactive protein was not different between groups (P = 0.091) and collectively was elevated to the greatest extent at 24 hours post exercise with no time main effect noted (P > 0.05). Neither creatine kinase activity nor C-reactive protein followed a normal distribution and therefore, data were log transformed prior to analysis. However, for ease of comparison to other published studies using these biomarkers, the original values are included in Figure 1. Pre exercise antioxidant reducing capacity was not different (P = 0.422) between NoP, NoA, ExP, or ExA (0.206 ± 0.067; 0.265 ± 0.071, 0.336 ± 0.077; 0.354 ± 0.063 mmol·L-1), respectively. Protein carbonyls were not statistically different between groups (P = 0.351), but experienced a peak from pre to 24–48 hours post exercise that failed to reach significance (P = 0.152). Creatine kinase activity was correlated to both protein carbonyls (r = 0.391, P < 0.00001) and C-reactive protein (r = 0.403, P < 0.00001). No statistical main effects or interaction were noted for peroxides (P > 0.05). Data for bloodborne variables are shown in Figure 1.

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