Paging Dr. Colter


Enclosed below is a letter written by a very popular doctor in our local running community. Dr. Colter’s letter is to arm your athlete or children with the knowledge to get the necessary testing need in regards to blood work. This letter has been created for distance runners as they suffer commonly from low Ferritin levels and Iron Deficiency. However, it is important to note that long to short sprinters who maintain a large volume of interval work can also suffer from low Ferritin levels and Iron Deficiency. These low levels mean fatigue, increased chance of injury, and drastically reduced sports performance. Doctors at times are hesitant or unaware to do the desperately needed testing to help athletes.
If an athlete’s levels become too low, it could take months even with treatment for the runner’s ferritin and iron levels to return to normal. Losing months in the middle of the track and field season is unacceptable. Often doctors will not test annually if they don’t see signs of low Ferritin levels and Iron deficiency. The letter provided by Doctor Colter is to be used to give athletes the language and references they need to get testing not just when symptomatic but as part of their annual plan. Testing becomes diagnostic work to help people maintain healthy levels for an athlete that must be higher than the average sedentary person.
Dear Doctor,
The runner you are seeing is requesting that serum ferritin be tested to assess total body iron stores. In my experience, there are many distance runners who are iron deficient without being anemic or microcytic and these runners are not able to perform optimally when their serum ferritins are below 30. Iron deficiency for runners is not simply an issue of having adequate hemoglobin. At least one muscle enzyme involved in lactate metabolism, alpha glycerol phosphatase, is an iron containing enzyme and inadequate levels of this enzyme make runners incapable of racing and doing hard training. The listed lower limits of “normal” for ferritin values vary from lab to lab, and are sometimes listed as low as single digits. Runners with serum ferritins below 30 do not perform well. I encourage distance runners who are running year round to test their ferritin twice a year. Testing at the end of fall cross country season and after outdoor track season is over in late spring will allow identification of runners who are deficient in total body iron stores in time to allow replenishment of those iron stores by supplementation prior to the next season of hard running. Many runners require iron supplementation while running in order to prevent the development of iron deficiency.
While iron deficiency is more common in female distance runners, male distance runners experience it as well. Hard running and racing lead to transient ischemia of distal colon and rectal mucosa with proven increased losses of iron in stool compared to sedentary controls.
In my experience, testing for the development of anemia is testing for the last thing that occurs in iron deficiency. Testing ferritin is much more helpful in detection of iron deficet in runners than testing hemoglobin alone. Certainly, testing hemoglobin, HCT, and MCV may be useful in discovery of anemia that is due to factors other than iron deficiency.
If I can clarify my opinion regarding iron in runners please feel free to contact me at
Kim Colter MD
Washington, MO
Am J Dis Child. 1988;142(2):165-169. doi:10.1001/archpedi.1988.02150020067030
study showing that adolescent runners with normal hemoglobin and low ferritin demonstrate improved running performance with correction of iron deficiency as measured by serum ferritin concentration.
Finch CA, Miller LR, Inamdar AR. Iron deficiency in the rat. Physiological and biochemical studies of muscle dysfunction. J Clin Invest. 1976;58:447–552.
rat study in which rats with normal hemoglobin and reduced total body iron stores have poorer exercise tolerance and higher rate of lactate production during treadmill exercise than iron replete group of rats with the same hemoglobin concentration.
Int J Sports Med. 1996 Oct;17(7):473-9.
Iron deficiency in distance runners. A reinvestigation using Fe-labelling and non-invasive liver iron quantification.
Study demonstrating the increased loss of iron in stool in runners who are racing and performing quality training.

Ryan Banta

Ryan Banta

Ryan is a successful high school coach. His athletes have achieved 76 school records, 2 top four finishes at the state championships, 3 district championships, 107 state semi-finalist (sectionals), 63 state qualifiers, 2 state records (3200 and 4x800), 14 national ranked events, 34 all state performances, 8 state champions, 7 runner up performances, and 2 Gatorade athletes of the year. Ryan is a USATF level II coach in the sprints, hurdles, relays, and endurance and recently earned a USTFCCCA track and field technical coaching certification.
Ryan Banta


Dad, Husband, Teacher, & Track & Field Coach. Author of Sprinter's Compendium Contributor @speedendurance @simplifaster
@seancooper_C4 Awesome Sean. Always good to have progressions. Different season different purpose. All good stuff!! - 28 mins ago
Ryan Banta
Ryan Banta

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