Home Blog A New Paradigm for Performance Testing – Part 1

A New Paradigm for Performance Testing – Part 1

Written on April 21, 2010 at 5:20 am, by Eric Cressey

Last September, I was put in touch with Dr. Rick Cohen, and we hit it off right away.  In addition to being a knowledgeable and super-qualified physician, Rick is also a baseball fan and performance geek just like me (I knew he was legit when I met him for the first time and he was rocking some Vibram Five Fingers shoes!).  Rick’s enthusiasm and forward-thinking mindset is absolutely contagious and has gotten his company, Bioletics, off to a great start.

Just to get a feel for what he does (and while remaining unbiased), I had my fiancee go through a series of performance testing they do (outlined below) and the entire process was fantastic.  One of the glaring issues discovered was low vitamin D, which has since been addressed.  Just two months prior to our work with Rick, I’d encouraged her to ask her primary care physician to check her vitamin D levels at a routine physical.  The physician’s response was “No.  You’re not post-menopausal.” The take-home message from this quick story is that not all physicians have all the information (or even a small fraction of the information, as Vitamin D plays countless roles in the body other than bone metabolism).

Since forward-thinking physicians are few and far between, it’s sometimes a challenge to find someone good in your area – and that’s where a guy like Rick and his company can come in to help out. I highly recommend Bioletics – to the point that I wanted to get Rick on-board for an interview to share some of his great information.  So, without further ado, Dr. Rick Cohen.

EC: Thanks for taking the time for an interview, Dr. Cohen.  Please fill us in a bit about your background, what you’re doing at Bioletics, and where the idea for the business really emerged.

RC: My pleasure.

It actually all started in your neck of the woods in Massachusetts. I had a medical practice with a focus on nutrition, athletic performance and aging there for over ten years. At the time, I was very dissatisfied with the assessment options available in the medical field. So, I developed a few of my own that could be done at-home with either a saliva or urine sample or a finger stick blood spot.


After moving to Bend, Oregon last year, I became involved in screening some of the girls on my daughter’s track team for iron deficiency and bone health. We also looked at vitamin D, which is a critical nutrient for both bone health and overall athletic performance.

When the results came in, it turned out that 95% of the runners low in iron. Additionally, 80% of the team was vitamin D deficient and more than 50% were mineral imbalanced.  After adding amino acid and recovery hormone panels to the screen, I repeated it with several local elite athletes.  Again, the results were shocking: not a single athlete was healthy from a biological standpoint.


At this point, it was pretty obvious that there was a need to turn the entire concept of human performance testing inside-out.  For years we’ve been obsessed with peripheral performance measurements-heart rates, VO2 levels and power output.  But the idea of looking inside an athlete’s body has been completely overlooked.

Giving athletes the ability to assess their unique, physiological needs represents a paradigm shift in athletic performance.  Despite all the marketing hype in the sports supplement industry, there’s no such thing as a one-size-fits-all formula for improving your athletic performance.

As athletes, our basic, biological needs are all very different.  We would never think of buying a bike, a baseball bat, or a pair of running shoes without trying them on or out for size.  Why do we use nutritional supplements-protein powders, recovery drinks and vitamins-without knowing if they are a good fit for us?

EC: Now, let’s talk about some of the specific things you guys can test.  I’ve been a big vitamin D guy for years now, and I know that’s one of your core tests.  What are you seeing thus far?

RC:  Optimizing your level of vitamin D3 is the single most important thing you can do for your health and well-being-and quite possibly your performance.  Interestingly enough, vitamin D isn’t really a vitamin at all.  It’s a hormone manufactured by your skin during critical periods of sun exposure.

Vitamin D is both a key building block and a cellular activator of almost every physical process.  It regulates more than 2,000 of the 30,000 human genes.  It’s an essential part of the endocrine system, as it controls several of the adrenal hormones, growth of cells, and production of enzymes.  It’s a powerful immune booster that provides a front-line defense against colds and flu as well as cancer and autoimmune disease.

Vitamin D is essential for optimum athletic performance, as it contributes to muscular strength and recovery while controlling physical reaction time, balance and coordination.


So far, almost every athlete we have tested has had sub-optimal levels of vitamin D (less than 50 ng/ml) except for one professional triathlete who trains in the sun in Australia all year.  Many athletes have been extremely low-under 25ng/ml.

Unless you can train outside year-round and/or make a conscious effort to get mid-day sun exposure; it is almost impossible to restore vitamin D to an optimal level-between  60 and 80 ng/ml-without supplementation.  When supplementing, the best results have come from the use of a sublingual vitamin D3 spray.  Gel caps, tablets and liquids are less effective.

The most important thing to remember is that your vitamin D level needs to be assessed and monitored. You can’t just take a random dose of vitamin D3 and expect to get results. Bioletics offers an at-home finger stick assessment that is virtually pain-free; it takes only two minutes and two drops of blood to complete.

EC: Now, how about iron?  It’s traditionally been a huge issue for female endurance athletes, but are you seeing it as much in females who aren’t on that level of training volume?

RC: Yes.  We learned this is a huge issue, especially among teenage girls.  In general, low iron is a problem among menstruating women because they lose blood every month.  With teenage girls, the issue is compounded by the fact that their diets tend to be lower in calories, red meat and protein-all of which are critical for obtaining adequate iron.


Iron is critical for athletic performance, as it carries oxygen in the red blood cells from the lungs to the muscles.  Severe iron loss results in a reduction of red blood cells (a condition known as anemia).  What most athletes are not aware of is that you do not have to be anemic to be suffering from low iron.  The most common signs of iron deficiency are fatigue, irritability, poor performance and slow recovery.

Another important point to stress is that while the assessment of red blood cell count, hemoglobin, hematocrit and serum iron are needed to diagnose anemia, these are not sensitive indicators when it comes to assessing deficiencies in iron stores-the supply of iron that’s actually available for the body to use.  The iron-binding protein, ferritin, is a much more reliable marker of functional iron stores.  We like to see levels of ferritin in females between 40 and 70 ng/ml.

EC: How about men?  Is too much iron a common finding?

RC: Good question.

In men, we are much more concerned with excessive iron than with low iron. This is because men do not bleed regularly and also tend to eat more red meat and calories than women.

The problem with too much iron is that it can create free radical damage in the body.  Just as iron in metal rusts, it has a similar action in your body.  Fortunately, your body has natural antioxidants to protect against the free radicals created by iron.  But when levels get too high, it can become a problem.  As we get older, excessive iron levels can play a role in the development of heart disease, cancer and immune disorders.

Excessive iron is linked to a genetic variation in iron absorption rates.  Hemochromatosis is a genetic disorder where the body absorbs iron too readily and iron stores can get tens or even hundreds of times higher than normal and cause severe organ damage. While the full blown disorder is relatively rare, many people have lesser variants which cause gradual accumulation of iron over time.  The second cause is dietary-we take in too much iron by eating iron-fortified foods like breakfast cereals and breads.


Just as with vitamin D, it is necessary to know your iron levels before you begin to take any kind of iron supplement.  The restorative dose of iron is generally 36mg daily while the maintenance dose for those with a history of low iron is 18mg daily. Taking a restorative dose without knowing a benchmark can push iron levels too high.  Playing it safe and taking a maintenance dose may not be enough.

Ideal levels of ferritin in men are between 70 and 100 ng/ml.  If your levels are higher than that, it is important NOT to take any iron supplements or eat iron-fortified foods.

We have seen iron levels in the upper 100s and low 200s in younger male athletes.  For these men, we recommended they monitor the levels every few years and to consider donating blood twice a year.  This will not only keep their iron levels from climbing, but will greatly help those in need.

Part 2 of this interview with Rick will run tomorrow, but in the meantime, I’ve asked with Rick to arrange for a special discount for EricCressey.com readers only.  If you head over to www.Bioletics.com and enter the coupon code ECCPP25 at checkout, you’ll receive $25 off the cost of your initial basic or complete panel.

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18 Responses to “A New Paradigm for Performance Testing – Part 1”

  1. Eric Says:

    Sounds like you hooked up with a gold-mine of a physician Eric 🙂 Vitamin D, iron… I’d like to hear his thoughts on EFA (in terms of absolute quantities as well as ratios of 3 to 6)…

    This is stuff that isn’t taken enough in consideration. Most people today are so deficient in many nutrients (most commonly, vitamin D, EFAs, zinc and magnesium), and this is a scary thought. Not to mention that, as the good doctor noted, most young athletes, especially women, do not ingest sufficient amounts of calories, especially from fats (including saturated fats) and protein, and usually eat way too many carbs!!!!

    Looking forward to part II…

  2. Carmen Bott Says:

    Great article Eric – I am a big fan of the whole-body approach to athlete and client screening. On my consulting team, I have a holisitic nutritionist, a sports med doc and a clinical naturopath. Many of our clients see them to optimize thier health. It could be as simple as adjusting something for a good night’s sleep, but those ‘lifestyle’ aspects need to be in order for the biggest training gains to occur! It is worth investing and ‘investigating’ into one’s health. Even in Canada, where our medical plan is good, is is still worth the private fees to see some of these key people! They will also recommend the best brands of supplements as many are bogus and end up in the toilet instead of being absorbed into our systems.

  3. Mike T Nelson Says:

    Good stuff EC.

    Vit D continues to be an issue for lots of people, esp us white guys from northern states.

    From nutrition experts that I talked to going back several years, many many women athletes are low in iron. Once any deficiency gets replaced, performance sky rockets.

    Great stuff, looking forward to part II
    rock on
    Mike T Nelson PhD(c)

  4. Eric Cressey Says:

    Eric, definitely some EFA talk in tomorrow’s Part 2.

    Carmen and Mike, thanks for the contributions!

  5. Walt Denkinger Says:

    If only you could convince high school girls (or anyone for that matter) to eat some pasture beef liver once (or maybe twice) a week, that would be a significant boost with the bounty of nutrients that come along with it. But then again, I might end up being the one with significant blood loss if they hear me suggest liver, hah, hah!

  6. Holly Kelly Says:

    For those of us who do not get adequate exposure to sunlight, what types of foods can help supplement our source of Vitamin D? And how much would we need of those examples to help increase to acceptable biological quantities?

  7. Zach Says:

    Great stuff, but is vitamin D supplementation really more important than omega-3’s? Does Dr. Cohen do any form of silent inflammation profile screening? I’m surprised no mention was made of this, as it seems one of the most vital screening procedures available today

  8. Robb Wolf Says:

    Great stuff as usual. I talked with Dr. Cohen today. We are test running this on one of our MMA athletes and I’m interested in the results.

    Keep up the great work.

  9. Benjamin Kusin Says:

    as far as “too much iron” being “too much” due to free radicals, can’t you just counter that to an extent by eating more veggies/berries?

    I can’t afford fish oil or any other supplements besides some whey powder and “vitamin” D. Sometimes I take zinc for anti-aromatase and magnesium for sleep (poor man’s ZMA) but that’s it. I would ask for dietary suggestions for those who can’t afford supplements, but such suggestions depend on individual biochemistry, which requires a test I can’t afford. Say hello to Mr. Murphy.

    But as we all know, good strength and performance can still be achieved with sub-optimal conditions. It’s just that if you wanna get the most out of your body, that’s when ideal matters.

  10. Brad Says:

    Funny, I grow up in Bend, Oregon before moving to New Zealand 8 years ago. I don’t suppose Dr. Cohen would consider following me over here? Finding a good Doctor, or therapist of any kind, is one of the biggest frustrations I have about living here (it’s lovely in other respects though..plenty of grass fed beef!)

    Thank you for sharing the information.

  11. Rick Cohen M.D. Says:

    My thoughts…

    Our assessments seem to suggest that young endurance girls are probably doing themselves more harm than good with their training. Low iron, inadequate amino acids and bone turnover are rampant.

    You can’t raise your vitamin D to optimum levels with food! 1000iu per 25 lbs of body weight of oral vitamin D is needed. We have found that gel caps are unreliable and we use a spray form of Vitamin D. Sun is best but need mid-day exposure 15 to 20 mins 3 times weekly. And this only works in lower latitudes or during late spring to early fall.

    We use the EFA panels to monitor silent inflammation. AA:EPA over 7 is a clear sign. Also, an elevated HgBA1C which we have added for carb tolerance is a sign as well. CRP could be used but found the other markers were more pinpoint. Clear out gluten for many, restore Vit D and EFA and almost always inflammation improves significantly.

    The question of cost is relative. Can you afford not to know the state of your health? The whole point is that without individualization, we can miss the boat. The majority of athletes we work with believe they have it dialed in but find
    with assessments that they have issues.

    And lastly, Brad. Where in NZ are you? Once my son is done playing baseball here, we are there!!

    And anyone who reads this please feel free to contact me at rick@bioletics.com. We want to be able to share this info. It is simple yet powerful.

  12. Jeff Says:

    How about a test for testosterone and growth hormone levels?

  13. Rick Cohen M.D. Says:

    One of our assessments if hormonal levels. We look at testosterone,estradiol and cortisol. These are general markers as they are not easily restored until EAA, EFA, Vit D are balanced. GH is more advanced and expensive marker to assess. It is best measured with IGF/IGF-BP ratio or a 24 hour urine. Something to look at once all else is balanced after 6 months to a year. Thje idea is to keep the cart before the horse

  14. Brad Josse Says:

    Hello Rick,

    And which high school does your son play baseball at? I played at Mountain View High School when Sid Spurgeon was the coach.

    In regards to New Zealand, I live in Nelson on the South Island, reputedly the “sunniest” spot in the whole country. This may well be true, too! We haven’t had rain in many a week, and even though it’s mid autumn, temperatures are around 70 degrees every day. Let’s hope it lasts….

  15. Michael Boyle Says:

    Why D3 vs the commonly available D2? Can you buy D3?

  16. Rick Cohen, M.D. Says:

    Good question…

    It is critical to recommend D3. There is no reason for anyone to take D2, it is not a human vitamin D. It is a vitamin D analogue that happened to be discovered before D3 by the University of Wisconsin, which patented it and it was then sold, and still is, as the only available prescription vitamin D, Drisdol. D2 or ergocalciferol does not exist in detectable quantities in the human body, only in tiny quantities in some plants and, as such, is “unnatural” when in the human body

    Currently, most scientists are specifying whether they use D2 or D3 in their studies but that was not always the case in the past. All studies done with D2 will need to be repeated with D3;

  17. Mark Says:

    “I knew he was legit when I met him for the first time and he was rocking some Vibram Five Fingers shoes!”

    I’ll have to let the 60-something yr old grandma I train know that her Vibrams make her “legit.” I’m pretty sure she wont’ care, as long as her bunions don’t hurt.

  18. Mary Says:

    Dr Cohen, thank you for promoting the overlooked importance of Vit D, so much more will be coming out related to this nutrient/hormone’s value.
    I would like to suggest that capsules can still be very effective if chosen from a reliable source (third party evaluated company), as I am proof of raising my levels back to goal range, without sublingual spray.
    When you refer to ‘metabollically appropriate fuel’ on your website, are you using metabolic typing (Wolcott’s work)? Curious if an MD is ideal for nutrition counseling, unless that MD studied nutrition as a separate degree. Sounds more suited for an RD, who had years of training rather than a semester or two. I’m stating merely due to concern that our culture is so ready to grab on to a list of ‘magic bullet’ answers, and we are a bit more complex than home testing kits. Admittedly, I dont know the details of the time you spend with each individual and maybe you only use the tools listed among your assessements as one peice of the puzzle. Still I admire the details explained in your blog post (with Eric) and look forward to more information.

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