Can supplementation with vitamin C and E alter physiological adaptations to strength training?

Area of Science:

• Exercise Physiology
• Nutritional Biochemistry
• Aging Research

Background:

• Antioxidant supplementation is a double-edged sword; moderate doses are beneficial, but high doses may impair exercise adaptation by inhibiting redox-sensitive signaling.
• Age may influence the body's response to antioxidant intake, suggesting differential effects based on age groups.

Purpose of the Study:

• To test the hypothesis that high-dose vitamin C (1000 mg/day) and E (235 mg/day) negatively affect resistance exercise adaptation in young adults.
• To investigate if the same high dosages of vitamin C and E positively influence adaptation in older men.

Main Methods:

• A double-blind, placebo-controlled study involving 73 volunteers randomly assigned to supplementation or placebo groups.
• Participants underwent an intensive 10-12 week resistance training program.
• Assessed changes in maximal strength, muscle mass, cell signaling, and muscle morphology.

Main Results:

• High-dose vitamin C and E supplementation demonstrated negative effects on exercise adaptation in young volunteers.
• Preliminary findings suggest potential positive effects of these high-dose antioxidants on adaptation in older men (further details not provided in abstract).

Conclusions:

• High-dose antioxidant supplements like vitamins C and E are widely used, particularly by athletes, with the belief they enhance performance and health.
• Scientific evidence generally does not support these assumptions, with some studies indicating negative impacts on exercise-induced adaptations.
• More randomized controlled trials are necessary to fully understand the complex effects of high-dose antioxidant supplementation on human adaptation to exercise.