Athlete Blood Test Reference Ranges

Standard laboratory reference ranges come from general reference populations and may not reflect athletes; a value outside them can be related to training, but its meaning is judged case by case.7,11 This tool puts the usual lab range side by side with what studies have reported in athletes, and shows where a value you enter sits on those ranges.

1. Marker
2. Sex
3. Your value (optional)

How to read the bars

Each bar shows one published range on the same scale. Grey is the usual laboratory range for the general population; blue bars are ranges reported in athletes. Where the bars differ is where an athlete can be flagged as abnormal by a standard lab while sitting in a range that studies have reported in athletes.

Why athletes differ

Training can change blood values: muscle damage can raise CK, plasma volume expansion can dilute hematocrit, and long-term heavy endurance training has been linked with lower testosterone in some men.1,11,18 That is why the same number can mean different things in a sedentary person and in an athlete.21

References

Every figure and statement in this tool is linked to a source: the original study where my article cites one, otherwise my own article on the topic. The small numbers in the text refer to this list.

  1. Dr. Antti Rintanen: Creatine Kinase Elevated in Athletes: Truths About High CK After a Workout
  2. Mougios 2007. Reference intervals for serum creatine kinase in athletes. British Journal of Sports Medicine.
  3. Baird et al. 2012. Creatine-kinase- and exercise-related muscle damage implications for muscle performance and recovery. J Nutr Metab.
  4. Dr. Antti Rintanen: Which Blood Tests Do Athletes Actually Need? A Doctor’s Evidence-Based Guide
  5. Solberg and Reikvam 2023. Iron Status and Physical Performance in Athletes. Life (Basel).
  6. Reinke et al. 2012. Absolute and functional iron deficiency in professional athletes during training and recovery. Int J Cardiol.
  7. Dr. Antti Rintanen: Ferritin Levels for Athletes: Why the Lab Reference Range May Not Be Enough
  8. DellaValle and Haas 2011. Impact of Iron Depletion Without Anemia on Performance in Trained Endurance Athletes at the Beginning of a Training Season: A Study of Female Collegiate Rowers. International Journal of Sport Nutrition and Exercise Metabolism.
  9. Study cited in “Ferritin Levels for Athletes: Why the Lab Reference Range May Not Be Enough” (reference 15)
  10. Lampe et al. 1986. Elevated serum ferritin concentrations in master runners after a marathon race. Int J Vitam Nutr Res.
  11. Dr. Antti Rintanen: Hematocrit in Athletes: What Your Blood Really Tells You About Performance
  12. Schumacher et al. 2002. Hematological indices in elite cyclists. Scand J Med Sci Sports.
  13. Brun et al. 2000. The paradox of hematocrit in exercise physiology: which is the normal range from an hemorheologist’s viewpoint?. Clin Hemorheol Microcirc.
  14. Bärtsch et al. 1998. [Pseudo-anemia caused by sports]. Ther Umsch.
  15. Bjerner et al. 2009. Reference intervals for serum testosterone, SHBG, LH and FSH in males from the NORIP project. Scand J Clin Lab Invest.
  16. Bhasin et al. 2011. Reference ranges for testosterone in men generated using liquid chromatography tandem mass spectrometry in a community-based sample of healthy nonobese young men in the Framingham Heart Study and applied to three geographically distinct cohorts. J Clin Endocrinol Metab.
  17. Brambilla et al. 2009. The effect of diurnal variation on clinical measurement of serum testosterone and other sex hormone levels in men. J Clin Endocrinol Metab.
  18. Lane and Hackney 2014. Reproductive Dysfunction from the Stress of Exercise Training is not Gender Specific: The Exercise-Hypogonadal Male Condition. J Endocrinol Diabetes.
  19. Lazarev et al. 2026. Testosterone-Optimizing Strategies in Athletes. Sports Health.
  20. Dr. Antti Rintanen: Testosterone in Athletes: What Your Blood Work Is Actually Telling You
  21. Dr. Antti Rintanen: Hemoglobin Levels in Runners: When Low Is Normal vs. Performance-Limiting

Sources

This tool is based on the articles below and the studies cited in them:

This tool is for general education. It does not interpret your own results, give personal recommendations or replace an assessment by your doctor.