Vitamin C and E Supplements May Reduce Benefits of Working Out

A new study in the Journal of Physiology suggests that taking vitamin C and vitamin E supplements reduces the benefits of endurance training, by interfering adaptations to exercise by the energy-making mitochondria of muscle cells.

Led by Dr. Dr Gøran Paulsen of the Norwegian School of Sport Sciences, researchers recruited 54 healthy, young men and women to receive either a placebo pill (containing no active ingredients) or a supplement providing a daily dose of 1000 mg of vitamin C and 175 IU (235 mg) of vitamin E. All of the participants, whether they received a placebo or not, did 11 weeks of fitness training. Every week the participants did 4 to 6 sessions of sprints, 4 to 6 minutes of exercise at 90% of maximum heart rate. They also did four to six sessions of 30 to 60 minutes each at 70 to 90% of maximum heart rate.

Neither the study participants nor the researchers knew who received the placebo and who received the vitamin pill. The researchers did a muscle biopsy of each participant before and after the trial to measure the effects of training on the numbers and functioning of the mitochondria.

At the end of the 11-week trial, the researchers did not find that either group had achieved significantly different respiratory capacity. Both the vitamin-takers and the placebo-takers had close to the same O2 capacity. However, when the researchers compared the mitochondria in the muscles of the two groups, they found that the placebo group's muscle had more mitochondrial enzyme activity, while the vitamin group's muscle actually, on average, lost mitochondrial activity.

Both groups had roughly equivalent gains in actual performance. Only the their mitochondrial activity was significantly different. 

See Also: Vitamins or Not?

But 12 other studies have found that vitamin C and vitamin E in lower doses either have no effect or can actually improve mitochondrial function. In a study of 16 athletes, 8 of whom received a supplement containing approximately 28500 IU (17.1 mg) of beta-carotene, 319 mg of vitamin C, instead of 1000 mg of vitamin C, and 72 IU (48 mcg) of vitamin E, instead of 175 IU, all of them used for 3 weeks instead of 11 weeks, the energy-making capacity of muscle actually improved. Giving athletes a supplement containing just 6 mg (10000 IU) of beta-carotene, 200 mg of vitamin C, and 48 IU (36 mcg) of vitamin E for just 3 weeks also improved muscle energy capacity. On the other hand, a study giving both athletes and non-athletes 2000 mg of vitamin C every day for 28 days found no improvement, and a study giving 20 athletes and 20 non-athletes 1000 mg of vitamin C plus 660 IU of vitamin E every day during a 28-day training program also found that energy making capacity of muscle declined.

The message seems to be that a small dose of antioxidants may be helpful, while a large dose of antioxidants may be harmful--or at least not do any good.

Should You Be Taking Vitamin C And Vitamin E If You Work Out?

For over 50 years, natural health gurus have been telling us that free radicals of oxygen are always bad and antioxidant supplements are always good, but the reality is not that simple. The process of releasing energy from glucose by combining it with oxygen produces free radicals, and the mitochondria in each cell have elaborate ways of capturing most of them so that they do not cause damage. Larger numbers of free radicals of oxygen escape the mitochondria when the muscles are using large amounts of glucose with large amounts of oxygen, as they do during endurance exercise, but cells have multiple methods of neutralizing them.

But what are the supplements that are really important for building muscle?

For most healthy people working out to build muscle mass, the branch-chain amino acids, especially leucine, are a helpful supplement.

In a Leeds Metropolitan University (UK) study, healthy men working to get into shape were given either 4 grams of leucine, a branched-chain amino acid, or a placebo on top of their usual diets. At the end of 12 weeks, the guys who got leucine were doing better all around. They had 30% higher strength gains than the men who had received placebo, and 40% higher muscle mass gains.

You will notice, however, that we did not insert a "buy now" link with an advertisement for leucine into the middle of this article.

Leucine is important for building muscle because higher levels of leucine keep the proteasomes, which are the "recycling units" of muscle for used proteins, from working too fast. Anytime you get as much as 5 grams of leucine with a meal, and that's the amount of leucine in a serving of most protein foods, your muscle cells will not go into breakdown mode for another 8 to 12 hours or so. This fact is one of the reason athletes need their sleep--and it actually is not a good idea to get up and eat a midnight snack.

See Also: Are Vitamin C Supplements Safe And Beneficial?

Leucine supplements, however, aren't necessary if you are already maxing out on your daily protein from meat, dairy, fish, eggs, and high-protein plant foods. It's only if you are for some reason restricting your protein, you've decided to become a vegetarian, for instance, or you have a kidney infection or some other medical problem for which your doctor has told you to avoid protein, that a branched chain amino acid or leucine supplement makes sense.

Everybody needs antioxidants. We just don't need them in huge doses. Moderation in supplementation is often the best way to get the most gains from any exercise program. Just a little is usually enough.