by Mark Wolff

When it comes to endurance sports performance and health we have all been exposed to the endless attempts to find the biggest gains in improving oneself. Most athletes that approach me are looking for an improvement in performance however my biggest concern is first health. I have always said that when we place our bodies under stress its important to make sure that the body can withstand the stress. If there is an underlying condition which the athlete is not aware of the consequences can be damaging if not life threatening.

As an endurance athlete and of course a human being nothing is more paramount than my health. When it comes to the human body the more you know about your own body the far better empowered you are to make the correct decisions when it comes down to it. I am sure most of you have heard about the term biological passport. This is used to monitor elite athletes in which profiles of biological markers of doping and results of doping tests are collated over a period of time. I have my own biological passport. I have 12 years of blood markers ranging from a wide variety of testing over time. However my passport is a biological health passport not a doping passport. I use this as a baseline for a range of different markers to ensure my body is in optimal condition to be placed under stress and to be able to perform at its peak when it comes down to it. As a sports nutritionist and physiology expert there is nothing more satisfying than getting blood results finding the anomalies and then using either treatment, nutrition or supplementation to correct them and get them back into line or even fortify them. However it goes much further than this. A general doctor will look at a range of bloods which are considered to be in the “healthy” range and give you the nod. I don’t do that I look at the bloods from an athlete perspective knowing that the individual is placing the body under a huge amount of stress whether it be an ultra distance marathon or triathlon. “Healthy” ranges are just not always good enough and in endurance sport tiny deficiencies or changes can equate to feeling flat or being able to really put down the hammer down and sustain it. Bloods don’t lie they will tell a story and guide a person in the right direction. Last year an elite athlete that approached me for assistance gave me the title “the legal doper”. I wasn’t sure how to take that as the word doping has many negative connotations associated with it. But on further thought I decided that to be able to legally enhance the human body is definitely the route to go as that has a big focus on health not just performance.

So my question to you all is do you have a snap shot of your health?  By that I mean a full set of bloods and the peace of mind that you are in good working order. Secondly once the doctor tells you that you are in good working order has he or she taken into account your active lifestyle. You are not a couch potato but a Ferrari engine and there is a big difference in requirements especially when it comes down to fuelling. Haematology is a fascinating pathway where hundreds of thousands of different chemical reactions and responses happen each day to what the body is going through. I would want to make sure that what is happening inside is life extending, performance enhancing and not destructive.

I have pulled up some bloods below just to deep dive a little and explain how some dietary and supplemental changes have made a huge difference in not just mine but other athletes lives.

Below shows an endocrinology profile of an athlete where I specifically requested  folate serum, red cell as well as vitamin D. 6 months prior to this test the results were not good. Vitamin D levels were sitting at 32, which by all means is healthy according to the medical spectrum and the folate levels were a lot lower. Vitamin D is actually the one vitamin that is scientifically and medically proven to strengthen the immune system. Its also the precursor to calcium absorption which means if you are an athlete you definitely do not want it to be on the low end at all. A very strong 5000iu D3 supplement pulled it up to 54 from 32 in 6 months and then the dose was dropped down to a D3 every 3 days at which stage the levels climbed further to 60. That is nearly double where it was before.

Noticeable differences in the athlete were not even such as a cold or illness in a two year period whereas prior to this at least 2-3 antibiotic courses a year. In addition there was a drop in shin splint pain until eventually it dissipated completely and never returned. Susceptibility to stress fractures had been reduced however I do need to mention in conjunction with the D3 a good calcium was also prescribed.

Below shows the increase from 54 – 60 at which stage we toned down the Vitamin D supplementation.
Its interesting to note this is an athlete who spends a lot of time outdoors and so the thought of sunshine providing Vit D although somewhat true is not always about exposure but about creation.

Below shows an athletes iron profile. It is in the normal range but again this is a serious athlete putting in many hours of training in a week. The feelings of fatigue that he experienced can sometimes be due to what we call athletes anaemia.  I felt the levels were too low although within the normal range so supplementation was brought into the picture.

Below shows the Iron supplementation over a 3 month period pushing the levels up nicely. I need to mention this athlete is a ovo-vegetarian although levels came up nicely the supplementation continued with a drop down to one tablet every 3 days to keep them topped up. The athlete noticed increased energy, better recovery and performance benefits.

No elite athlete wants to see the below especially when aiming for a top position in a race. Low red cell, low haematocrit is not a desirable result especially knowing that you are limiting your haemoglobin production and this is so crucial for muscle and organ function. The last thing you want is limiting it especially if you are an athlete. You can also see that the iron is low and understanding haematology you should know that red blood cell, haemoglobin and iron are all interlinked.  The below shows low transferrin levels which can relate to iron binding capacity. The athlete did not have sufficient blood in the diet. Taking a look at the individuals lifestyle we discover an over trained athlete under nourished meaning absolutely poor nutrition to support the exercise volume and intensity. Multiple menstrual cycles in a month led to more blood loss than normal and major changes needed to be made to the diet to correct this.  Again Vitamin D levels could come up nicely especially since this was an athlete that suffered from numerous bone related injuries which could be a direct result of nutrient deficiency.

Below is another female athlete with dedicated 6-7 days of training combining 70-100km run weeks with strength training. Waking up daily feeling faint, dizzy and often bouts of nausea until the day she fainted and hit her head on the treadmill. The below shows clearly an iron deficiency as the cause. The inability to feel energetic, wake up fresh and be able to train with a smile on your face is not the way one would want t be feeling each day. Dragging yourself through life from day to day is terrible. It took so many weeks to convince her to get bloods done and with all the delays it set a domino affect into play leaving her to do them out of desperation. Prevention is always better than cure.

The below was sent to me after a blood test by a concerned athlete. After questioning the timing of the blood test the cause was clear that the athlete gave the blood in a completely dehydrated state. It was after a hard long run in the heat, followed by a oats breakfast and cup of coffee. This is an athlete that usually trains fasted and on that particular day he noted he felt very thirsty and battled through the heat. Then went for bloods. Pick your blood test days carefully you don’t want to skew the results.


I can bring up hundreds of blood results over the years where each will tell a different story. Sometimes the biggest percentage gains in sports performance need to actually start with the health aspect and only once that is solid then one can move to the next level which is proper tweaking of nutrition and natural supplementation to gain a little more. There are no quick fixes and most people I come into contact with tell me about all the wonderful and weird supplements they take to give them the edge. They have absolutely no idea what they are talking about because what they could be taking might be doing exactly the opposite and hurting their health. Know your status first then we can talk.

In conclusion, as an active person start your biological health passport, get tested fairly regularly and get an idea of your health status over time. Anomalies might come and go but at least if you have a history of what is going on inside your body you will be in a much better position to manage the risks as well as improve your health and performance goals.


Take care

all the best


Mark Wolff is a certified exercise & sports nutritionist, endurance nutrition and physiology expert with over 20 years experience. An endurance multi-sport athlete with a running, triathlon, mountain biking and weight lifting background, he works extensively with professional and amateur athletes in a variety of sports disciplines as well as those just wanting to change their lifestyles. He firmly believes that a person can only reach their full potential when their health and nutrition is given the proper focus. Mark’s focus on nutrition and physiology is not just on training and racing, but he places major emphasis on recovery, immune system health, emotional stability, stress management and performance. Mark is co-founder of 32Gi, a sports nutrition company, focused mainly on health and endurance nutrition. He is also co-founder of Rapid Recover focussed on pneumatic compression equipment to improve circulation for recovery and health.




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Jay November 22, 2018 - 8:29 am

Great article Mark. For the above female with the low RBC counts, what steps did you take to turn the situation around?

Mark Wolff December 11, 2018 - 4:37 pm

Hi Jay it was actually a process. I first requested B12 and folate levels to be tested as well as red cell, the levels were very high and from an athletes point of view the iron definitely needed to come up. However we were not happy about the low hematocrit and red cell. I requested the input of a sports physician I work with and it was discussed in detail and finally testing for inflammatory markers and injury related issues which could be asymptomatic. Finally it did boil down to inflammation due to major muscle breakdown mainly due to an injury, which actually had caused an increase in hepcidin levels in the blood at least that was the direction. After undergoing rest and rehab along with iron supplementation, and proper sleep and good nutrition the levels eventually came back to normal. It did take time.

Thiathu November 23, 2018 - 5:50 pm

I would love to do this tests

SO YOU REALLY THINK YOU HAVE YOUR SPORTS NUTRITION RIGHT? – The Fitness Freak February 5, 2019 - 9:54 am

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jennikruse November 25, 2019 - 7:58 am

Hi Mark
What folate (serum and red cell) do you aim for?
How do you utilize the fasting lipogram to advise an elite athlete on their nutrient requirements?
Any particular D3 or iron supplement you recommend?
Thank you ?

Mark Wolff November 25, 2019 - 8:06 am

Hi Jenni I am at a conference today but will respond when I get the first opportunity 🙂

jennikruse November 26, 2019 - 6:19 am

Thank you. I look forward to hearing from you

Mark Wolff November 26, 2019 - 12:39 pm

Hi Jenni apologies for the delayed response 🙂 just extremely hectic time of the year.
With folate levels interestingly enough I usually look at an athletes history first and the markers most crucial to me are HCT, HGB levels and from there I do look at the Iron Profile B12 and Folate levels. HCT for me is a nice defining marker for an an athlete. It can show an athletes health and ability to perform. I generally see loads of athletes with lowered HCT due to either mainly iron issues either inflammatory absorption blocking due to over training or other factors. In some cases this shows in elevated ferritine and low serum iron. I have not had many athletes where red cell issues have been directly related to folate and b12 however in a few cases I have seen depleted stores impacting red cell. The interesting thing was in one case the athlete was taking folic acid and eating a load of leafy greens yet they were still low. I sent him to a sports physician I work closely with and she picked up a major inflammatory response due to a severe injury which he had no idea he had. Generally I like to see the s-folate sitting around the 20-30 mark and red cell over 450- 500 or even higher. It is never a full proof science as with haematology many factors come into play. With most athletes I have worked with in South Africa and abroad I find mainly iron absorption issues, testosterone issues (males) due to the excessive loads they place on their bodies and in females mainly iron deficiencies in quite a few cases elevated CRP levels especially in Comrades runners. Lately we have started testing IgG and IgM levels as well especially in those athletes that are consistently getting ill. In the majority we have found some susceptibility to illness with hyper IgM levels and have started some testing with a specific beta glucan to see if we can try to improve the markers and lower the risk of infection. With me it all starts with analysing the nutrition, sleep patterns and training loads the bloods are always a bonus when they agree to it as it shows a lot as I am sure you know. In some cases athletes refuse and I can only think it boils down to illegal substance ingestion. I am currently doing a masters abroad with a focus on haematology , endocrinology and radiology. Thesis topic might be of interest to you its around stress fractures mainly being caused by bone density issues due to nutrient deficiency (mainly vitamin D) and not necessarily just over training. The idea is to show that the main factor involved is the lack of nutrients allowing for bone density issues leading to a stress fracture. We have sent tens of athletes that have had stress fractures for blood tests and all of them so far had low vitamin D levels. According to serum “health levels” they were in line with a healthy marker. However we know that the markers were dropped to 20 a while back and for an athlete we feel this is just too low I want to see the levels over 50 🙂 also from an immunity perspective.

Mark Wolff November 26, 2019 - 12:43 pm

I did not answer you on lipogram testing. I usually request it to check cholesterol levels markers it definitely helps me guide them on nutrition. If I find elevated LDL levels I will almost always move towards a lowered fat diet and insist on the fats being mainly unsaturated. I also would recommend COQ-10 dosing and consumption of red rice 🙂
On the Vitamin D3 side I advocate two Sfera 5000iu its an excellent plant based vitamin D and then Metagenics also have a 5000iu. Problem is most pharmacies including Dis-Chem do not stock anything over 1000iu unless you go get a script for a slightly stronger dose. Health stores do stock them.
As for Iron the two I recommend are Ferrous forte, also QuadroFer is excellent a few sports physicians stand by it.

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