Supplements for Triathletes: What Works?

The world of endurance sports is being inundated with supplements manufactured with the endurance athlete in mind. It’s easy to get wrapped up in supplementing. Before you know it you’re taking a handful of pills in the morning, a special powder for your water bottles, and another handful of pills in the afternoon. The goal of this series of posts is to help you understand which supplements appear to be effective through solid research, and which may not be worth the money.  Of course, individuals may have different needs, but for the purpose of this article, I am discussing the general endurance athlete population. But first, one important concept…

Although it is sometimes difficult to get all of the nutrients needed through diet, it is almost always better to try to meet your nutrient needs through foods than supplements. Foods, especially fruits and vegetables, have enzymes that optimize bioavailability (how much you absorb) of nutrients within the food. When nutrients are isolated to be made into supplements some of those enzymes are lost. Bioavailability of supplements varies depending on many factors, including the supplement quality, how the supplement is manufactured, what the supplement is, time of day you take it, what you take it with, and on and on. Some popular supplements have been shown to have absorption rates of less than 5%!  It is because of the variables above that you should strive to get the majority of your nutrients through an ultra-healthy diet. Put the same emphasis on diet as you do training.

Of course, there are supplements that appear to benefit endurance athletes in well designed, double blind studies. Below is a summary of well-researched supplements. There are more supplements that may be effective. This list is simply a list of those that consistently show to be effective.

The “A” List

The following supplements have consistently shown through quality, peer reviewed research to be effective for endurance athletes.

  • Multivitamin – although multivitamin supplements do not appear to improve performance in endurance athletes, they are generally an accepted general health strategy. Endurance athletes burn through a lot of nutrients during and after workouts, which can lead to depleted micronutrients. Even if these depletions are marginal, they can affect performance, recovery, and immune function. There is debate around the whether multivitamins are actually beneficial for athletes. A couple years ago a small study saw very slight performance declines in the athletes taking a multivitamin. After reviewing this study, there are many flaws to it and in my opinion it is not a valid conclusion. Therefore, I base my opinions on the many other studies that are well organized. These studies generally conclude that a multivitamin will not enhance performance, or may very slightly. However, I have yet to come across a study that tests micronutrients as part of the study. To truly understand the correlation between micronutrients and performance, a study of this sort should be performed. I can say, however, that through my experience with professional and elite amateur athletes that when we find deficiencies in an intracellular micronutrient test, then correct for those deficiencies, I typically get very positive feedback from the athlete about improved performance and quicker recovery. *Processing and brand make a difference with multivitamins, as a poorly processed multivitamin is not well absorbed. Take as indicated. My top choice for a multivitamin is from the Douglas Labs Klean Athlete line. Find it here: be ordered with a physician code, use the following: 2142213   
  • Fish Oils/Omega 3’s – fish oils should be an essential supplement for every endurance athlete. These super powered anti-inflammatory and antioxidant supplements are one of the most well-researched and supported supplements. They fight free radicals and oxidative stress, and reduce post-exercise inflammation. *Processing makes a difference. Omega 3’s in the triglyceride form have shown to be superior. The huge majority of omega 3/fish oil supplements out there are in the ethyl ester form because this form is easier and cheaper to produce. One over-the-counter brand that is in triglyceride form and can easily be found is Nordic Naturals. The ideal EPA to DHA ratio for athletes is 4:1. Most supplements are 2:1. This ratio is fine, but if you can find a 4:1 supplement (such as Nordic Naturals ProEPA) that is ideal. I recommend 1200-1800 mg per day with food. My top pick is Nordic Naturals ProEPA, which can be found online or in many health food stores and pharmacies.
  • Vitamin C – strenuous exercise increases production of free radicals, which can damage muscle tissue, increase muscle soreness, and create inflammation. Vitamin C is an effective antioxidant, and can be taken in high quantities safely, easily, and cheaply. Antioxidants fight the production of free radicals. Vitamin C is also an immune booster and high intensity training decreases immune function. Most professional triathletes and ultramarathoners I see have deficient immune systems throughout the peak of their training. There are well run studies that show vitamin C does reduce post-exercise muscle pain and speed recovery, then there are well run studies that conclude it likely does not. My opinion…vitamin C is easy to take, is cheap, boosts the immune system, and probably helps with recovery. I recommend taking it throughout the peak training season. My top pick for a vitamin C supplement is the Emergen-C packets, as they are bioavailable and easy to take. One packet per day (1,000mg) is adequate.
  • Iron (when indicated!) – iron should be taken under the guidance of a physician. I will repeat, iron should be taken under the guidance of a physician. The need for iron supplementation should be shown through blood testing (see my blog post on blood work monitoring). There are hundreds of thousands of endurance athletes blindly taking iron. When iron is indicated, this supplement can be essential to your well-being and ability to train and race. It can boost performance WHEN NEEDED. When taken in excess, it can be hard on the liver, cause gastrointestinal problems, inhibit zinc absorption (an important nutrient for athletes), and cause fatigue. There are several different forms of iron. My top choice is iron carbonyl, as it appears to be the most bioavailable form. Take as directed by a physician and be sure to supplement zinc when you are supplementing iron. Iron will typically cause increased intestinal gas. If you require iron supplementation, be sure to read my blog post about iron supplementation, as there are important steps to optimizing absorption of the supplement. My top pick for an iron supplement is Douglas Labs Time Released Iron (product number 7962). 90 capsules cost $10.20. Find it here:  good zinc supplement also comes from Douglas labs, the Zinc Lozenges. Both must be ordered with a physician code, use the following: 2142213   
  • B12 (when indicated!) – when used correctly and at the appropriate time, B12 can help ward off anemia and pre-anemia. If you are monitoring your blood work during your training, a sudden change in the MPV (which indicates the shape of the red blood cells) and slight drop in hemoglobin and hematocrit suggest that it may be time to supplement B12 or increase your folate intake. Folate intake is best increased by using a vitamix type blender (see my blog post on Juicing). I have found that in high performing endurance athletes, B12 is often high in the blood, however deficient in intracellular (within the cell) micronutrient tests. More to come on this in a future blog post. B12 is best taken either sublingually (under the tongue), which can be found at almost any pharmacy or health food store, or via intramuscular injection, which costs more and typically requires a visit to a clinic.
  • Magnesium – research shows magnesium can increase lactic acid clearance, decrease muscle aches and cramping, and possibly improve power output and performance. Magnesium is plentiful in foods, however some studies show that in endurance athletes magnesium levels are very slow to rebuild once depleted by prolonged muscle use or training in hot, humid weather. In addition, alcohol, coffee, refined sugar, and high salt intake can deplete magnesium. Being we endurance athletes love our beer, coffee, and frequently partake in salty food binges, supplementation should be considered during peak training, especially if in hot, humid weather. Magnesium is also closely linked to potassium and calcium. When magnesium levels drop, potassium and calcium will soon follow. Drops in potassium result in severe muscle cramps. Drops beyond certain levels can be dangerous and will surely end your race and possibly send you on a ride to the hospital. 500-1000 mg/day during training (can be part of a multivitamin). For two days prior to a race, up to 1500 mg/day can be taken, however if it leads to an uneasy stomach, back off to your regular levels (too much can cause diarrhea). My pick for a magnesium supplement is Douglas Labs Magnesium Aspartate, a readily bioavailable form (product number 7405). 250mg per pill, 250 pills per bottle, $20.90. Find it here:  Must be ordered with a physician code, use the following: 2142213   

Supplementing Iron In Athletes: The How and Why

In past blog posts, I have briefly touched on iron supplementation. This practice is common among endurance athletes, especially triathletes, cyclists, and long distance runners. It is done because of the high risk of anemia and pre-anemia due to increased red blood cell turnover secondary to training. However, iron supplementation should be done with caution and under the watch of a professional.

My general rule of thumb is to avoid iron supplementation until you see an indication for supplementing. Indications include a reduction in hemoglobin, hematocrit, and red blood cell numbers, along with an increase in size of red blood cells compared to your base numbers and beyond what is normal secondary to training. I am a strong advocate for regular blood work monitoring in athletes training more than 10-12 hours per week, especially if there is intensity added to some of those workouts. There is research that shows high iron levels of iron can cause gastrointestinal problems, fatigue, appears to increase the risk of cancer, and it does interfere with zinc absorption, a very important micronutrient to endurance athletes. Therefore, iron should not be blindly supplemented. When iron is indicated, it is crucial to performance, when it is not it can be very detrimental to your health, and decrease performance. Blood work monitoring should be performed by a doctor familiar with working with endurance athletes.

Before simply treating iron deficiency by taking a pill, it is important to take some time to consider why this deficiency may have occurred in the first place. For starters, a few questions that should be asked include:

  • Is there blood loss occurring in the body (gastrointestinal bleeding, heavy menses, infection, etc)?
  • Other disease processes?
  • Are there absorption problems?
  • Are co-nutrients deficient?
  • Is the athlete over-training?
  • Is this definitely iron deficiency and not folic acid/folate or a B12 deficiency?
If iron supplementation is the answer, it is time to start iron. However, iron supplementation is not as easy as simply taking a pill for some. Some people have trouble absorbing iron when it is supplemented by itself. In fact, in the last month I have been contacted by three professional endurance athletes that cannot seem to shake their anemia/pre-anemia, which is hugely affecting their performance. After reviewing tests and further testing in all of them, it became apparent that they had trouble absorbing iron in the pill form.
How to Supplement Iron
An iron supplement should be paired with a significant source of organic vitamin C (non-synthetic). Organic vitamin C greatly enhances iron absorption. The key is that it must be “organic”. Synthetic vitamin C, such as that found in supplements does not have nearly the iron absorption enhancement effect as organic. Iron should not be taken with dairy products, or within 1 1/2 to 2 hours of drinking coffee or soda (this includes diet soda). 
The ideal method for supplementing iron is to take it with a fruit smoothie. Vitamin C and protein containing lactoferrin increase absorption of the iron. Interestingly, dairy products, specifically cow’s milk have been shown to decrease iron absorption, while whey protein supplements containing lactoferrin increase absorption. The following recipe tastes delicious:
1 banana
1 scoop vanilla whey protein
1 cup frozen mixed berries
1 cup frozen strawberries
Coconut milk
(optional: 1 tbsp peanut butter or 1/3 cup rolled oats)
While supplementing iron, you should also supplement zinc, as iron supplementation decreases zinc absorption rates.

Which Iron Form to Take

There are several different forms of iron out there. My top pick among the different forms is iron carbonyl, as it appears to be the best absorbed form of iron because of slower absorption rates, which have also shown to decrease the side effect of gastrointestinal discomfort and decrease potential toxicity. A company I am particularly fond of is Douglas Laboratories (no I am not a paid spokesman). They make a great iron supplement in the form of time released iron carbonyl. The benefits of having it time released are typically less gastrointestinal side effects, which are very common when supplementing iron (gas, loose stools, or constipation).

You can find this supplement here: To order you must use a physician referral code. You can use the following: 2142213. Just remember, test first!

If you are interested in testing and don’t have a relationship with a doctor, I am available for blood work monitoring to athletes both locally and distantly. Simply contact me at to inquire. This is performed through the 51 Speedshop Performance Advising ( 

Folate For Athletes: Don’t Ignore This Micronutrient!

Over the last few years, iron has become a supplement found on the shelves of most endurance athletes. Rightfully so, depleting iron levels leads to pre-anemia and anemia. For more information on iron, see my blog post on the topic (

However, somehow the micronutrient folate has not received adquate attention. Endurance athletes have come to believe that if they are abnormally fatigued and feeling anemic, it is because of an iron deficiency. Yes, iron is the most common deficiency leading to anemia, but folate deficiencies also lead to anemia. In my clinical experience, folate deficiencies are not overly uncommon among 140.6 and 70.3 distance athletes. Whereas, iron is more difficult to prevent strictly through diet in high level endurance athletes, folate deficiencies are typically easily prevented simply by eating the right foods.

Folate is a B vitamin. It plays an important role in red blood cell production and tissue repair. It is also an important component of cell division, especially in cells with higher turnover rates. In endurance athletes, the red blood cells have a significantly higher turnover rate due to the stresses of training. It is not stored in the body, therefore adequate amounts must be ingested every day. A healthy diet is essential to ingesting adequate amounts. 

Folate and folic acid are often used interchangeably. However, I treat them differently. Folic Acid is a synthetic, lab produced form of folate. Folic acid is often fortified in foods. In my experience, folic acid supplementation and/or ingestion is not equivalent to eating folate in its unadulterated form (as is the case for most micronutrients). In my clinical experience, folate repletion occurs rapidly and the benefits on the red blood cells can often be seen within days when done through increasing dietary folate. Folic acid supplementation has often been disappointing in athletes I work with that rely on this method due to travel or other life situations that inhibit their ability to eat high amounts of folate.

Endurance athletes should try to ingest at least one meal per day high in folate. Folate is prominent in spinach, romaine lettuce, chard, broccoli, lentils, red beets, and alike vegetables and legumes. The easy way to get a high concentration of folate is by juicing (see my blog post on juicing here: If juicing doesn’t appeal to you, salads easily supply what you need.

Antioxidants and Endurance Athletes

Antioxidants. From athletic performance and anti-aging to heart disease prevention and cancer treatment, antioxidants are touted as key components to fighting disease and optimizing wellness. Once considered the “fountain of youth”, these powerful, free radical fighting nutrients truly are amazing. They fight oxidative stress, a process that leads to cellular degradation and even cell death.

Following their discovery, antioxidant supplements quickly found their way into endurance sports, and have been a mainstay supplement ever since. They are touted for their anti-inflammatory effects in athletes, their ability to offset free radicals, and aid in recovering from training sessions. There is a large body of research on antioxidants for endurance athletes. The conclusions are nothing short of…well, completely confusing.

And so, I figured I’d write a post covering a few important points about antioxidants as they relate to endurance athletes. But first, some fun facts about antioxidants…

Antioxidants are most abundant in nature in fruits and vegetables. Antioxidant is a generic term for a nutrient or organic chemical that combats oxidative stress. There are many different antioxidants, and several different “types”. Three major types are micronutrients, enzymes, and phytochemicals (which include polyphenols). Well known micronutrient antioxidants include vitamins A, C, and E, and CoQ10. Many enzyme and phytochemical antioxidants are unnamed. Thousands of different ones have been identified, and thousands more are thought to exist. These too are found abundantly in fruits and vegetables.

And now for some important notes about antioxidants as they relate to endurance athletes…

Yes, antioxidants do benefit endurance athletes. They have shown in legitimate research to decrease perceived exertion in endurance athletes during exercise, significantly reduce muscle soreness and inflammation following workouts, and significantly decrease oxidative DNA damage. However, our approach of isolating antioxidants in highly concentrated supplements may not be as effective as we once hoped or suspected. As is almost always the case, nature’s delivery method is far more effective than ours.

I have made the comment in past posts that I believe we will one day find out that the enzymes and phytonutrients present alongside antioxidants in nature are integral to making certain nutrients absorbable and useful to their full potential. Most supplements do not contain the enzymes and phytonutrients, which are often lost in processing. A couple recent studies came to this conclusion. In one study, supplemental vitamins C and E showed no reduction in markers of oxidative DNA damage, however the authors found that in those individuals studied that had a higher intake of fruits and vegetables, decreased oxidative DNA damage was noted. In the other study, researchers studied the effects of a powdered fruit/vegetable juice concentrate versus supplemental vitamins C and E. They found that although the powdered juice concentrate had much less vitamins C and E, the antioxidant effects were significantly greater. They concluded this to be related to phytonutrients, which remain present in some powdered fruit/vege juice concentrates and whole food supplements (Cancer Epidemiol Biomarkers Prev 2000; 9(7): 647-52 and Med Sci Sports Exerc 2006; 38:6, pp1098-1105).

Antioxidant supplementation may not be all good news, however. There are a couple very important considerations for endurance athletes. The first is that some polyphenols appear to inhibit iron absorption (Penn State 2010, August 23, Polyphenol antioxidants inhibit iron absorption). As an example, green tea, which is known to be high in polyphenols, has been shown to inhibit iron absorption. This is a big deal, as iron is the key micronutrient for red blood cell production and function (see blog post on red blood cell turnover). It is also a micronutrient that has a high turnover rate in endurance athletes. Supplementing iron blindly (aka without monitoring blood levels) is generally considered to be a poor decision, as an overabundance of iron in the system is linked to several serious health problems, including cancer risk (see my blog post on supplementing iron for more information). Therefore, it is important to be aware of the relationship between polyphenols and iron, and thus pay attention to where you are getting your antioxidants. Avoid the polyphenol sources, and stick with the fruits and veges ideally. Interestingly, Vitamin C, a powerful antioxidant, enhances iron absorption. The second consideration is that over-supplementing antioxidants (levels not established) may actually elicit a pro-oxidative effect, which is the opposite of the desired anti-oxidative effect. In addition, some recent research suggests that completely inhibiting post-exercise inflammation may be detrimental to recovery.

So, in summary, yes, supplementing antioxidants appears to be beneficial, however the form of the supplement matters. Research continues to support combination antioxidant supplements, such as those containing a combination of vitamins A, C, E, and selenium. However, powder or whole food supplemental forms of antioxidants appear to be superior. But, the most effective form is through eating lots of fruits and vegetables. The key in supplementing is to keep it in moderation. Unfortunately, we don’t know how much is too much yet, hopefully this will be established soon.

My recommendation, get a Vitamix (or akin) and fill it with fruits and veges of many different colors each day. Have a fruit smoothie for breakfast. Eat lots of salads. Do these things and you will get plenty of unadulterated, wonderfully bioavailable antioxidants that are partnered with their enhancing phytonutrients and enzymes. If you just can’t make this happen, reach for the supplements (of the type mentioned above), because they do appear to work, just keep it in moderation by sticking to the recommendations on the bottles.