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Dietary Supplements for Athletes

If there is a chronically recurring topic/question I get or see it involves the issue of dietary supplements.  Both athletes and the general public are endlessly fascinated by them with unscrupulous marketing companies taking advantage of that fascination.  To address the issue, I’m presenting more or less the entirety of  Chapter 11 from my Applied Nutrition for Mixed Sports Book/DVD Bundle.  This list is not meant to be comprehensive and there are always newer products that may show promise down the road.

Chapter 11: Dietary Supplements for Athletes

If there is a single area of sports nutrition that is constantly changing (in terms of the products being marketed) and which athletes are always interested in it’s dietary supplements. As I mentioned in Chapter 2 of this book, I consider supplementation to be the third tier of the pyramid (after overall daily nutrition and around workout nutrition) in terms of what athletes should concern themselves with. Even there, I divide dietary supplements into several categories and want to present another pyramid for dietary supplements, shown in Figure 1 below.


Heirarchy of Dietary Supplements

Just as with the overall nutritional pyramid, I put supplements into three categories in terms of their relative importance. The first is simply general supplements, either acting as nutritional insurance or essential nutrients (such as fish oils) that almost all mixed sports athletes can benefit from.

Once those have been taken care of consistently, supplements that directly impact on performance and which have good research backing should be considered. Once that tier has been taken care of, various supplements which I term esoterica (this category is always changing) can be considered.

The tip of this pyramid should only be considered by athletes who have all aspects of both their overall diet, around workout nutrition and other supplements taken care of. Simply, esoteric products can, at best, provide the last tiny percentage point for performance and recovery. Worrying about that when the majority aspects of diet and supplementation have not been taken care of consistently is pointless.

General Use Supplements

.As noted above, general use supplements are those products that basically all athletes can not only benefit from but probably should at least consider. Short of correcting a frank deficiency, they don’t generally have vast noticeable improvements in performance per se; rather they simply support overall health and daily nutritional requirements.

Many of the nutrients discussed below are simply those that are commonly deficient among athletes, others (e.g. vitamin D, fish oil) are usually deficient in just about everyone. Generally, these supplements should be taken with meals and doses can be split morning and evening and taken with meals.


As I mentioned in a previous chapter, there are both reasons to believe that athletes need increased amounts of vitamins/minerals due to their heavy training as well as that they get more due to increased nutrient intake. I consider a basic one per day multi-vitamin/mineral a cheap nutritional insurance. It won’t hurt and may correct and/or prevent any minor deficiencies.

For the most part, I see little need to purchase super expensive formulations, athletes who are obsessed with such can buy cheaper and simply take two (split morning and evening). I would note that men, especially those who eat a lot of red meat, may want to find a product that does not contain iron. Women, due to their propensity to develop anemia (due to both dietary choices and monthly blood loss) should choose a product containing iron.

As a final note, under no circumstances should athletes assume that they can ignore important aspects of their overall diet because their multi- will ‘cover it’.

Protein Powder

As discussed in a previous chapter, protein powders have been staple of athletic nutrition for decades and exist somewhere between food and a supplement. While obtaining all but the highest intakes of protein can generally be done with nothing more than food, protein powders can provide convenience and flexibility for athletes having problems meeting their protein needs. They can be especially valuable when athletes travel and may have their normal food patterns disrupted. Specific types of protein powder are discussed in Chapter 4.

For the most part, buying protein powders commercially is a losing proposition, you will pay twice as much for half the product and I recommend that athletes find reliable online suppliers to purchase protein powder in bulk. I’ve provided a few online resources at the end of this book that I trust to provide quality product at a good price.

Fish Oils/Essential Fatty Acids

If there is a single nutrient that is almost impossible to achieve adequate amounts of with the modern diet (outside of the handful of people who eat a lot of fatty fish), it’s the w-3 fish oils. In a very real sense, fish oils ‘do everything’ and impact on not only overall health but help to control inflammation, promote fat oxidation, inhibit fat storage and a host of others. It’s a list of benefits that seems almost too good to be true but the research is there.

Due to their general unavailability in the food supply, supplementation is almost necessary and both pills (containing varying amounts of the active EPA/DHA) and liquids are available. Both are acceptable and some people simply prefer the liquids (which can be used on salads or in blender drinks) to pills (which often cause burps).

Years ago, flaxseed oil was suggested as a source of the essential fatty acids as it contains the parent fatty acid that can be converted into EPA/DHA. However, that conversion is exceedingly inefficient in most people (vegetarians appear to be an exception to this for some reason) and I do not feel that flax is an acceptable substitute for fish oil supplementation. I suggest that athletes find an omega-3 fatty acid source that they like and consume it daily (again, consuming cold water or fatty fish is also a possibility).

While little research has examined athletes, I recommend a total intake of EPA/DHA of 1.8-3.0 grams per day. A fairly standard capsule of fish oils may contain 180 mg EPA and 120 mg DHA (300 mg total fish oils) so that daily dose would require 6-10 capsules per day which should be split at least morning and evening (taken with meals).

Higher concentration fish oils are available (at a premium cost) but may be preferred by athletes who don’t like swallowing pills.   Again, the goal should be a total EPA/DHA intake of 1.8-3.0 grams per day regardless of how it is obtained.


As I mentioned previously, calcium deficiencies are not unheard of in athletes.  This is especially true if athletes can’t or won’t consume dairy products. And from an overall health issue, calcium is critical, perhaps more so for female athletes to ensure good bone health later in life. Of course, telling athletes to take something on health grounds is often a losing proposition so consider that a great deal of research suggests that calcium (and dairy calcium more than other forms) may improve body composition.

A minimum daily intake of 1000mg calcium is recommended and I’d note that a single serving of most dairy foods will contain roughly 300 mg. If you consume 3 servings per day of dairy, you needn’t supplement. If your intake is less than this, you may need to consider a supplement (multi-vitamin/mineral pills never contain sufficient amounts).

Calcium citrate is the preferred form and most calcium products will contain some Vitamin D as well (see next). Calcium supplementation should be split into two doses consumed morning and evening with meals as this provides better overall uptake.

Vitamin D

It’s not an exaggeration to say that concerns about Vitamin D levels are currently a “hot-topic” in nutrition. And while Vitamin D can be made by the body (through exposure of the skin to sunlight), it’s turning out that Vitamin D deficiencies are absolutely epidemic, especially for people who work indoors and/or live in cold weather countries where sun exposure is minimal.

Athletes who are forced to train indoors for weather reasons are potentially at risk as well. This is true even of athletes who train outdoors part of the year as Vitamin D levels in the body fall fairly quickly when regular sun exposure is eliminated.

It also looks like maintaining adequate Vitamin D status may be a key to optimal athletic performance although direct research is lacking. Unfortunately, determining serum levels of Vitamin D intake to determine optimal levels of supplementation requires blood work.

Athlete with access to testing should strive for levels of 50 ng/ml or higher. It requires 100 IU’s of Vitamin D to raise serum levels by 1 ng/ml and athletes with access to blood testing can determine their daily dose that way (e.g. to raise levels from 30ng/ml to 50 ng/ml would require 2000 IU’s per day).

Failing that, a daily supplementation level of 2000 IU’s should be safe and reasonable for most. Blood work is still preferred and this is another place where mega-dosing (greater than perhaps 10,000 IU’s per day) can be problematic. More isn’t better.

For athletes who don’t want to take yet another pill, tanning once or twice weekly provides another way to obtain Vitamin D. Don’t go nuts with it (as excessive UV skin exposure carries its own health risks) but small amounts during cold weather or periods where sun exposure is minimal are not harmful and may help.


As mentioned previously, both zinc and magnesium are often deficient in athletes.  Zinc is often low in athletes who forego red meat and magnesium losses increase with heavy training. Both are critical for optimal performance and various processes important to athletes. As well, many find that the combination of the two taken at bedtime helps with sleep, a process critical to overall recovery.

On average, a daily supplement of 25 mg of zinc (any form is basically fine) with 400-500 mg of magnesium (citrate is the preferred form) taken 30 minutes before bedtime helps many go to sleep. While many commercial zinc/magnesium products contain B-6, this seems to hurt sleep for some people and I suggest buying the ingredients separately if they are taken. I’d note that magnesium oxide, which is the most commonly found form of magnesium is poorly absorbed, as noted above citrate is the preferred form.


A supplement that is insanely popular with bodybuilders (who think it builds muscle, which it doesn’t), glutamine is an inessential amino acid that is heavily involved in immune system function. Given the propensity of athletes to suffer problems with their immune system secondary to heavy training, anything that helps support the immune system is potentially good.

The research on glutamine and immune system function is actually rather mixed, some finds that it works while other work has not. It’s more likely that branched-chain amino acid (BCAA) supplementation, discussed in the next section, works as well if not better.

From a purely experiential standpoint, I have found that the consumption of high doses of glutamine and Vitamin C at the first sign of a cold tends to stop it in its tracks. Two to three grams of glutamine with 500mg of Vitamin C taken multiple times throughout the day seems to do the trick.


The term anti-oxidant actually refers to a massive number of different compounds (including but not limited to Vitamin C, Vitamin E, Vitamin A, Beta-carotene and many others) that help to scavenge free radicals in the body. Free radicals are formed during heavy exercise and early ideas held that this was damaging to the body.

And while it is true that excessive free radical production can cause problems, research actually has found that free radical production is critical in signaling adaptations to training. Blocking free radical formation can actually inhibit proper adaptation to training, especially endurance training.

Additionally, while research on diets that are high in anti-oxidants (e.g. whole food diets containing lots of fruits and vegetables) often find health benefits, studies using isolated anti-oxidants have generally not found the same results. This again points to the importance of obtaining most nutrients from whole foods rather than isolated pills.

For the most part I do not advocate the intake of high-dose isolated anti-oxidants for mixed sports athletes under most circumstances. An exception is the high-dose Vitamin C mentioned above with glutamine when an athlete starts to feel a cold coming on. This is especially true during primary training phases where excessive anti-oxidant supplementation have the potential to impair optimal adaptation.

However, during the season, when the goal is primarily to survive competition (which may be very frequent depending on the sport), supplementation may be useful. Some athletes report decreased soreness and improved recovery. Since the goal in-season is competition and not improving fitness or training adaptations, this may be worth considering.

So while avoiding anti-oxidants during the main training period is probably the best course of action, there may be some merit to supplementation to survive a heavy competition season.

Performance Supplements

As opposed to the general use supplements which are meant to support basic health, etc. performance supplements are those that have (or are purported to have) direct impacts on performance in training or competition.

In this section, I’ve listed a handful of products that are supported (to one degree or another) by at least some type of strong research into their efficacy. This is basically what separates supplements in this category from the esoterica category discussed last. When products in the esoterica category have sufficient research behind them, they move into the performance supplement category; this happens rarely.

With that said, I’d like to look at the handful of current performance oriented supplements that mixed sports athlete might consider using. These are all products with at least some amount of supporting research (in healthy human athletes) which make them a worthwhile consideration. Again, this should only occur after the daily diet and other aspects of around workout nutrition and general use supplements are being implemented consistently.


If there is a single dietary supplement in existence that can be said to work, creatine is probably it. With several hundred studies supporting it’s effectiveness and safety, creatine is arguably with one the must-have supplements for most athletes including team and mixed sports athletes (with a few notes made below).

Creatine has been shown to positively impact all manners of performance measures ranging from repeat sprint performance to weight room performance and others (if creatine has a negative impact it is typically on endurance due to a slight weight gain that occurs). Most of the reported side-effects of creatine have not been borne out by research (see comments on cramping in the previous chapter) and the biggest danger of creatine use is a slight weight gain of 1-2 kg due to water retention.

For athletes who need to make weight, this can be a problem and, as noted in the chapter on hydration and cramping, will increase fluid requirements. Even those athletes who need to make a certain weight class can use creatine supplementation during their main training phase and go off at least one month before competition; this will give the body time to get rid of the extra water and drop the weight.

While a number of “high-tech” creatines have come and gone, for the most part bulk creatine monohydrate works as effectively, if not more effectively, than the other types. The only possible exception is a micronized creatine which can be useful for athletes who have stomach problems with the standard monohydrate. All of the other variations on creatine (i.e. creatine ethyl-ester) are no more effective but do cost more.

Traditionally, creatine has been supplemented one of three ways, which I’ve described below:

  • The method used in the studies was to consume 20 grams of creatine in 4X5 g doses per day for 5 days. While this loads the muscle with creatine the fastest, it can also cause stomach upset in some people.
  • A less aggressive protocol would be to consume 10 g/day of creatine for 10 days. While this will take longer to reach saturation levels, most people report less stomach problems.
  • Finally, creatine can simply be taken at a dose of 3-5 grams per day for roughly a month.

The only difference in approaches is the speed of loading. Athletes may simply wish to put 3-5 grams of creatine in their pre- or post-workout shake and be done with it. Maintenance doses are 5-10 g/day depending on the athlete’s size after loading has been finished (larger athletes need more to maintain muscular levels).

I should mention that some percentage of athletes are creatine non-responders. For various reasons, they receive no benefits from creatine, no performance improvement and no weight gain. If an athlete uses creatine in one of the above dosing patterns and no weight gain occurs, they are a non-responder and can discontinue use.

As noted above, after loading, creatine levels will drop gradually over a period of about a month if no more is consumed. Athletes who need to drop water weight should discontinue creatine supplementation at least 30 days prior to the weigh-in of their event.


A fairly recent addition to the performance supplement arsenal for mixed sports is beta-alanine. Acting as a buffer of acidosis in skeletal muscle, beta-alanine can improve certain types of performance, especially in activities that rely heavily on anaerobic metabolism (e.g. maximal efforts lasting roughly 30-60 seconds). At least one study found that beta-alanine plus creatine improved weight room gains; mixed sports athletes looking to increase strength/power or muscle mass may want to consider beta-alanine.

The biggest drawback to beta-alanine is the required dosing schedule which is 400-800 mg of powder 4 times per day (for a total dose of 1.6-3.2 grams per day). In some people, beta-alanine can cause a tingling/itching/flushing sensation. This isn’t dangerous, simply irritating. And the dose must be split in this fashion for optimal effects.

Branched-Chain Amino Acids (BCAA)

The BCAA are leucine, isoleucine and valine, three amino acids that have a branching chemical structure (hence their name). Many studies have found that BCAA and specifically leucine is critical for stimulating skeletal muscle growth and protein synthesis and for this reason BCAA are often suggested for athletes trying to gain muscle mass.

Other aspects of performance have also been measured with early work suggesting that BCAA might decrease fatigue during high-intensity exercise; an equal amount of work found no effect. In some situations, BCAA may actually hurt performance through one of several mechanisms (e.g. ammonia production).

I’d note that BCAA are found to some degree in all high quality proteins with the highest concentration being found in the dairy proteins: whey and casein. This is yet another reason for athletes to consider adding those specific proteins (either in powder or food form) to their diet; this will help to ensure that BCAA intake is optimal.

In that vein, my general feeling is that, if sufficient dietary protein is being consumed (e.g. you’re following the recommendations in this book), additional BCAA is unnecessary and will have little to no effect. In most studies where BCAA had a benefit, it was on a background of inadequate protein intake.

As noted above, BCAA may protect immune system and athletes involved in very heavy training might consider extra. BCAA are fairly expensive, with daily doses running from 10-20 grams per day and supplements can be bitter tasting. I would consider BCAA supplementation as something for athletes to use only when everything else in their diet was taken care of.

Joint Health Supplements

Depending on the specifics of their sport, mixed sports athletes often undergo a tremendous amount of joint pounding, either as a function of running around the playing field or due to other athletes slamming into them (e.g. football, mixed martial arts). While keeping joints healthy isn’t strictly a performance issue, clearly an injured athlete won’t be performing well, if they can perform at all.

A number of supplements are potentially beneficial for overall joint health (and or to deal with certain types of injuries). The most common cocktail is chondroitin sulfate and glucosamine sulfate, both of which provide the building blocks for connective tissues and have been shown to help heal certain types of joint injuries (especially arthritis).  MSM (methylsulfonylmethane) may also have some benefit.

One problem with these supplements is that they often take 4-6 weeks to start working. In that vein, people who report no benefit after 4-6 weeks of proper dosing don’t ever seem to get a benefit. Put differently, if the supplements haven’t worked after 4-6 weeks, they aren’t going to start working and you can stop taking them. Dosing for glucosamine and chondroitin are in the range of 1.5 grams per day of each, MSM is often added in amount of 1.5 grams as well.

Additionally, papain and bromelain, the enzymes found in raw pineapple have been shown to have beneficial effects, probably by controlling inflammation. I’d mention fish oils here again as they can help control inflammation, which is key to keeping injury rates down. This is yet another reason to ensure adequate fish oil intake on a daily basis.

Pre-Workout Stimulants

Stimulants of varying sorts have been popular with athletes for decades and for good reason, they work. Stimulants before training or competition can improve performance in a variety of parameters important to athletes. These range from direct performance improvements (e.g. increased strength or power output) to glycogen sparing due to increased fatty acid use to many others.

I would note that a potential drawback and this is especially true of excessive stimulant use is cramping. As well, under the wrong conditions (usually dehydration plus heat and humidity plus intensive training), there have been deaths associated with excessive stimulant use. If there’s a lesson to be learned here it’s that more is not better.

The old standby as a pre-workout stimulant is simply caffeine, perhaps the most used compound on the planet. Doses of 3-5 mg/kg (so 180-300 mg for a 60kg athlete) taken 30-60 minutes prior to training or competition can improve certain types of performance, and certainly those important to mixed sports.

Caffeine hits peak levels in 60-90 minutes and lasts several hours so, unless training is exceedingly long, a single dose is usually sufficient; you won’t run out. Here again, even ignoring the cramping issue, more is not better and very high doses of caffeine, especially on an empty stomach can cause stomach upset.

I would mention that, in theory, stopping caffeine for several days prior to an important competition will make it work more effectively; in practice, individuals used to using caffeine on a day to day basis won’t ever do this due to negative effects such as headaches and performance decrease. So a neat idea in premise but almost impossible to accomplish in practice.

There are numerous other stimulant type products, with perhaps ephedrine the most well known, available to athletes and companies continue to look for pre-workout boosters. Many show up on the banned list (caffeine is not banned since it is so universally used) and, as noted above, excessive stimulant use can cause problems with cramping.

Before trying any stimulant product, an athlete must check to see if its banned and test it during training to see if there are any negative effects. As noted above, never try anything new on game-day.

For the most part, I recommend athletes simply stick with good old caffeine. For standardization I prefer tablets (usually available in 100-200 mg doses) as the caffeine content of coffees can vary widely and the amount that needs to be consumed to hit the 3-5 mg/kg dose above usually means excessive fluid intake which causes problems with having to pee all the time.


Pretty much everything else in the world of supplements falls into this category. Hundreds of products come out yearly and 99% of them fade away to never be heard of again. While I remain optimistic that a true new ergogenic compound will come along, the history of the supplement industry simply doesn’t support it.

When you have your daily diet, around workout nutrition and everything else dialed in, you can worry about the stuff in this category. Just realize that, 6 months from now, it will probably be long-forgotten because it never had any chance of working.

As I noted above, occasionally a product that starts out in the esoterica category will have sufficient research appear to move it into the performance supplement category. While athletes always tend to think that the newest magic pill will be the one that this will happen with, the statistics simply don’t bear this idea out.

As I mentioned above, easily 99% of the products in this category disappear within 6 months to never be heard from again. Waiting to see if the newest magic bullet actually pans out is the only thing that makes logical sense.

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