Beam, W. C., Fong, F. C., Koch, R. A., & Fortuna, J. L. (1998). The effect of chronic ascorbic acid supplementation on strength following isotonic strength training. Medicine and Science in Sports and Exercise, 30(5), Supplement abstract 1251.

Intense exercise causes membrane lipid peroxidation. Strength training may be impaired if significant peroxidative damage in skeletal muscle occurs. Ascorbic acid (Vitamin C) is a very effective antioxidant that protects lipids against damage from free radicals. It also plays a role in connective tissue synthesis associated with strength gains. It has been suggested that ascorbic acid taken chronically with strength training could produce greater strength gains.

The effects of chronic ascorbic acid (1,000 mg/d) on the development of isokinetic muscular strength in young adults during an 8-week isotonic strength training program were measured. Ss were divided into four groups:

One has to question the validity of using isokinetic movements to test isotonic training effects.

Only in the knee extensor group was there a significant difference between the ascorbic acid/strength over the placebo/strength groups.

It is highly unlikely that ascorbic acid would have a selective effect on muscle reaction to training. A conservative interpretation of these results, which differs to that offered by the authors, is that ascorbic acid does not significantly enhance strength training effects when testing is of a different contraction modality to training. However, the non-significant results might result from the isokinetic testing and not truly reflect isotonic training effects.

Implication. This investigation does not fully assess the effects of ascorbic acid supplementation on isotonic strength gains.

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