Could These Healthy Ingredients be Blocking the Positive Effects of Exercise?

We all know that exercising is good for us. Countless studies have shown that exercise helps with weight management, insulin sensitivity, mood, cholesterol control, and even the immune system.

But what you might not know is that you could be ingesting ingredients right now that are actually blocking the benefits of exercise.

And what is worse, you have probably been told these ingredients make you healthier.

The ingredients are vitamin C and vitamin E, both of which fall under the “antioxidant” category of nutrients.

You might be thinking I am crazy; how in the world could these two vitamins negate the positive effects of exercise?

I was surprised as well, so let me take you through a recent study1 that just might change the way we look at our supplements.

The Surprising Study About How Antioxidants Can Block The Benefits of Exercise

The study, published in The Proceedings of the National Academy of Sciences, took 40 people and divided them into two main groups.

One group was given 1000mg of vitamin C and 400IU of vitamin E daily, while the other group was given a placebo.

Both groups were then subjected to an aggressive 4-week training routine that included 20 minutes of biking or running, 45 minutes of circuit training, and a 20-minute warm-up and cool-down, five consecutive days per week.

Everything else remained identical, the only difference being the addition of the antioxidants in half of the participants.

Also important, before the 4-week training routine began, blood tests were drawn from all participants to establish baseline levels of glucose metabolism, insulin sensitivity, adiponectin and oxidative stress.

The Antioxidant Effect

After four weeks, final blood tests were taken to determine if there was an antioxidant effect.

In the group that received the placebo, the 4-week exercise program increased glucose metabolism, adiponectin levels and insulin sensitivity. It also increased the body’s production of its own antioxidants – glutathione and superoxide dismutase.

Some studies have shown that vitamins C and E can hurt your weight loss

This is extremely positive information, reaffirming the benefits of exercising on a regular basis. It’s especially interesting that exercise increases adiponectin because high levels of this hormone are absolutely essential for fat burning.

So what happened to the group that consumed the antioxidants (vitamins C & E)? The short answer is, “Nothing”.

After the 4-week exercise program, the people in this group did not show any increase in glucose metabolism, adiponectin levels or insulin sensitivity. They also did not show an increase in the body’s production of its own antioxidants (glutathione and superoxide dismutase).

Well, I shouldn’t say absolutely nothing happened; the oxidative stress in the antioxidant group was in fact lower than the placebo group’s. One would think this would be a good thing, yet it appears to be precisely the reason why these antioxidants blocked the positive effects of exercise.

What is Behind the Antioxidant Effect?

Let’s explore oxidative stress, free radicals, antioxidants, and how they relate to exercise in a little more detail.

When you exercise, you increase your metabolism, creating oxidative stress in the form of reactive oxygen species (ROS), or free radicals, that attack our tissues at the cellular level. On the other hand, antioxidants have the opposite effect. They eliminate the kinds of free radicals that result from oxidative stress.

What the study demonstrates is that the formation of free radicals during and after exercise is a crucial mechanism that signals your body to increase glucose metabolism, adiponectin levels and insulin sensitivity, while also causing your body to produce more of its own antioxidants – glutathione and superoxide dismutase.

And by taking even relatively small amounts of antioxidants, like 1000mg of vitamin C and 400IU of vitamin E daily, you are eliminating the oxidative stress that is triggering this highly beneficial health cascade.

It appears more beneficial to allow your body to recover from the free radicals created by oxidative stress naturally than to interfere with this process by taking these particular antioxidants.

It’s similar in a way to testosterone replacement therapy. Once you replace your body’s natural testosterone with outside sources, you body stops producing its own. This is why responsible doctors are reticent to prescribe this therapy unless one’s testosterone levels are extremely low.

Should I Swear Off Antioxidants?

The obvious question is what to do with this information. As with any new research, it brings up more questions than answers.

A whole foods diet is better than a diet full of supplemental antioxidants

We do not know whether this information extends to other antioxidants or just vitamin C and vitamin E. So let’s talk about just these two vitamins for now.

The recommended daily intake (RDI) for vitamin C is 75 mg. Studies show that a daily dose of 200mg fully saturates tissues, and higher dosages have shown few increased benefits.2 I don’t see a big reason to supplement for this vitamin because it is very easy to get 75mg to 200mg from natural food sources. For example, just one orange will provide you with around 100mg of vitamin C.

The RDI for vitamin E is 22.5 IU, and studies show that mega doses (averaging 400 IU) can actually lead to increased mortality3. Again, it’s easier and safer to get vitamin E from natural food sources like spinach, almonds, eggs, and olive oil.

A recurring theme in medicine is that “more is often less”. Just because an ingredient has a positive effect does not mean taking more will magnify the positive result. And just like with the exercise study, taking more vitamins can lead to worse (not better) results.

What Next?

I will be diving much deeper into this topic because of the many unanswered questions. I would appreciate your questions and insights below.

I know it would be easy to jump to conclusions here, but I believe it is wiser to wait for more evidence. So for now, I would simply lower your dosage of vitamins C & E to the RDI if you plan on embarking on a vigorous exercise program.

Until next time,

Steve Sisskind, M.D.

Hi, I'm Dr. Steve Sisskind, Chief Medical Officer & Founder at RealDose Nutrition.

As a young physician, I struggled because my patients came to me with serious health issues, but I didn't have the right tools to help them. Medical school taught me how to put "band aids" on their symptoms with drugs and surgery, but not how to address the root causes of their problems.

Years later I discovered a better approach... based on the fundamental idea that the power of nutrition can transform your health and vitality. But there's a lot of confusion... What foods should I eat? Which supplements should I take? What does the science say?

I have dedicated my life to answering these questions... And I share this knowledge with you every day here at RealDose Nutrition.

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1. Michael Ristow, Kim Zarsea, Andreas Oberbachc, Nora Kloting, Marc Birringer, Michael Kiehntopf, Michael Stumvoll, C. Ronald Kahn, and Matthias Bluher. Antioxidants prevent health-promoting effects of physical exercise in humans. PNAS 2009 May;106(21):8665–8670.

2. Sebastian J. Padayatty, MRCP, PhD, Arie Katz, MD, Yaohui Wang, MD, Peter Eck, PhD, Oran Kwon, PhD, Je-Hyuk Lee, PhD, Shenglin Chen, PhD, Christopher Corpe, PhD, Anand Dutta, BS, Sudhir K Dutta, MD, FACN, and Mark Levine, MD, FACN. Vitamin C as an Antioxidant: Evaluation of Its Role in Disease Prevention. Journal of the American College of Nutrition, Vol. 22, No. 1, 18–35 (2003).

3. Miller Er, 3.; Pastor-Barriuso, R.; Dalal, D.; Riemersma, R. A.; Appel, L. J.; Guallar, E. (2005). “Meta-analysis: High-dosage vitamin E supplementation may increase all-cause mortality”. Annals of internal medicine 142 (1): 37–46.

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  1. Good Morning Dr Sisskind, Im am 50 years old and I do my exercise routine in the morning from 8:00-9:00. I would take a vitamin C sometimes in the morning before I go for my jog. Is it a timing thing? Would I get the full benefits of my exercise if I take my vitamins after my exercise or a few hours after? Or is it just better to lower the dose ?

    • Dr. Steve Sisskind

      Hi Laura,

      Thank you for writing in and for sharing your thought with us! Yes to both questions, it would be best if you could take your Vitamin C a few hours after your exercise and then lower your dose if take it daily. We can easily get the same from our diet especially from citrus and a few vegetables. Hope this helps! Make it a healthy day!

  2. I’m 75 and I take a slew of vitamins recommended by my doctor who is into holistic medicine. He orders them from some place. He warns us about buying many vitamins/supplements from our local drug stores. I have been trying to lose weight. I do exercises, walking and I drink several glasses of water a day. I eat a healthy diet. I’m not sure what is hindering me from losing weight.

    • Dr. Steve Sisskind

      Hi Pat,

      Thank you for writing in and for sharing your concerns with us! You seem to be doing everything right which does not explain the slow weight loss. I suggest that you speak with your personal doctor and have him reevaluate you. It could be that a few adjustments need to be made in order for the weight to start moving in the direction we want. Make it a healthy day!

  3. If I don’t have time to take the Formula No.1 a full thirty minutes before a meal, is it a waste to take it at the beginning of the meal? My morning schedule is especially tight, and I often don’t have this 30min window. Please let me know what you’d suggest.

    • Dr. Steve Sisskind

      Hi Susie,

      Thank you for writing in! If you are unable to take the formula no.1 30 minutes before your meal, take it as soon as you remember. In the studies, the ingredients were administered 30 minutes prior to meals. So in an effort to keep things consistent with the studies we recommend taking the capsules 30 minutes before each meal. This is why we suggest taking it as close to 30 minutes before your meal as possible, however if you forget, please do not skip the dose. Hope this helps! Make it a healthy day!

  4. Are Vit C and E beneficial supplements for people with aggressive homone positive breast cancer ?

    • Dr. Steve Sisskind

      Hi Faye,

      Thank you for posting your concerns! I cannot conclusively say whether Vitamins C or E are beneficial for Breast Cancer patients but do know that some doctors advise supplementation only when absolutely necessary. In that regard, if you are planning on adding vitamins to your regimen, be sure to seek the wisdom of your personal doctor before getting started. Hope this helps! Make it a healthy day!

  5. Interesting. Be good to know if MSM or Astaxanthin would also suppress natural production ofor glutathione during exercise.

    • Dr. Steve Sisskind

      Hi Liz,

      Thank you for writing in and for posting your concerns with us! That is indeed a very interesting topic and I would be glad to do some research on that. As soon as I have found a reliable source (medical journals or other related publishing) I will be sure to post it here. In the meantime, my initial research shows that unlike Melatonin, Astaxanthin does not seem to affect glutathione levels as drastically. I will need to follow up on this to know for certain. Stay tuned! Make it a healthy day!

  6. I have heard that before about ascorbic acid not being the same. Maybe they should repeat the study with goji berries and mixed tocopherols and tocotrienols that are naturally sourced. Do four groups; control, goji, mixed natural e, goji + e.Big pharma would never fund this.

    • Dr. Steve Sisskind

      Hi Chuck,

      Thank you for writing in and for sharing your concerns with us! Goji berries are slowly gaining popularity in the supplement industry and a study such as this would further help in its understanding. I shall try my best to dig a little deeper and share my research with you. Stay tuned and make it a healthy day!

  7. I take 2 prenatal vitamins a day.. it helps with energy.. I’m in menopause and my hormones are out 9ff wack…I keep working out, lifting weights and I can’t get that high feeling back… I also take 400 wellbutrin, 50 MG of prestige… do I need an adrenal vitamin?

    • I’m having trouble losing weight also.. I’m 51 years old..

    • Dr. Steve Sisskind

      Hi Lacheer,

      Thank you for writing in and for sharing your concerns with us! I am deeply sorry but cannot recommend an adrenal vitamin for you. You may want to speak with your personal doctor about this and before changing your daily regimen of supplement. Several factors may need to be considered as well as an evaluation of your current health. However, I always recommend that you get a balanced diet, enough sleep and water as well as a form of exercise to keep you in the peak of health. Hope this helps! Make it a healthy day!

  8. I found drinking orange juice made my ankles swell. When I take 3,000 mg of vitamin c my gums don’t bleed. Although, since the vitamin c I was taking is granulated and not sold in stores, only on line. I found a vitamin c that is in pill form but not as easy to digest. Do you make a vitamin c that is granulated?

    • Dr. Steve Sisskind

      Hi Esther,

      Thank you for writing in and for sharing your concerns with us! An Ascorbic acid or Vitamin C supplement is one of the few additions we are looking to make in the near future. A granulated supplement seems like a good idea as it is well tolerated and quickly utilized by the body. I will be sure to pass this on to our Research and Development team and get their thoughts. However, I do pray for your continued patience as this is still a ways away from completion. Again, thank you for writing in, Esther! And make it a healthy day!

  9. This result is likely due to the fact the what is sold as “vitamins” are merely just one component of the real vitamin and are therefore really more like drugs with results that are other than you expect or can’t predict. For example most “vitamin C” is just ascorbic acid, versus the entire real vitamin C molecule and ascorbic acid actually is a pro-oxidant (vs. anit-oxidant) and actually pushes real vitamin C out of the body. Same idea with “vitamin E” or any of the others, including B complex, etc.

    • I have heard that before about ascorbic acid not being the same. Maybe they should repeat the study with goji berries and mixed tocopherols and tocotrienols that are naturally sourced. Do four groups; control, goji, mixed natural e, goji + e.Big pharma would never fund this.

  10. Thanks for this valuable information, I was taking vit E daily, I’ll stop doing it since I eat spinach, almonds and olive oil in my salads. For Vit C I just drink orange juice, nothing else, so I guess that’s not bad.
    ONe question… Is it true that vitamin “D” RDI of 4000 mg help you to feel more active?
    Thank you so much

    • Dr. Steve Sisskind

      Hi Myrna,

      Thank you for writing in and for posting your question! Everyone needs vitamin D to promote strong bones, immune function, healthy cell division and muscle strength for whole-body benefits. That said, I am not certain if the improved energy levels can be attributed to Vitamin D, alone, but do know if you are healthy, you will definitely have a better chance of fighting off fatigue and inflammation. We recommend a daily intake of 1,000 IU to augment one’s lack of sun exposure. As with any dietary supplement, it is always best to talk with your physician or other licensed healthcare practitioner before adding high-potency vitamin D to your regular supplement program. Hope this helps! Have a healthy day!

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