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Vitamins that are ruining your workout

Nina Reschovsky is a freelance health and fitness writer. Her work has been featured in a number of publications including SheKnows, Women’s Health, Q by Equinox, The Sunday Telegraph, and more. She has a BA from Boston University and a ...

Skip these supplements

Vitamins C and E are antioxidants responsible for boosting your immune system and helping your body fight off bacteria and viruses. So the more you get the better, right? Wrong.

Skip these supplements

Vitamins C and E are antioxidants responsible for boosting your
immune system and helping your body fight off bacteria and viruses.
So the more you get the better, right? Wrong.

Woman taking vitamin

Researchers from the Norwegian School of Sport Sciences in Oslo recently published a study in the Journal of Physiology indicating that taking vitamins C and E may hinder muscular endurance.

The study analyzed 54 healthy young men and women for 11 weeks. Participants were asked to complete a running-based endurance program that consisted of three to four training sessions per week, most of which involved running. Half of the participants were given 1,000 mg of vitamin C and 235 mg of vitamin E daily (the standard amount in store-bought supplements) and the other half were given placebo pills. Researchers monitored participants through blood samples and muscle biopsies before, during and after the trial.

Results found that only those in the placebo group showed markers of the production of the muscle mitochondria. Mitochondria, often referred to as our “cellular power plants,” are essentially the power cells within muscles. Producing mitochondria means you’ve gained strength and endurance in that muscle, whereas not producing it means you haven’t, and that your workout was ineffective.

Two groups performing the same workouts, but only half of them gained muscle strength. What gives?

According to the researchers, the antioxidants in these high doses of vitamin C and E may have blocked the development of muscular endurance, thus inhibiting muscle growth.

"Our results indicate that high dosages of vitamin C and E — as commonly found in supplements — should be used with caution, especially if you are undertaking endurance training,” said Dr. Goran Paulsen, who led the study.

But don’t eliminate vitamin C and E from your diet completely! According to the National Institute of Health's Office of Dietary Supplements, men should have 95 mg of vitamin C each day and women 75 mg, while both men and women should have 15 mg of vitamin E.

This is a pretty small amount, and you certainly don’t need to take a supplement to get enough. Vitamin E is found naturally in foods such as nuts, vegetable oils and green vegetables, while vitamin C is found naturally in citrus fruits, potatoes and broccoli.

Try these recipes instead of supplements

More health tips

How to get your daily dose of Vitamin C
The science behind your sugar and salt cravings
Why you should get addicted to salmon

Photo credit: Ryan McVay/Photodisc/Getty Images
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