Article Text

Download PDFPDF
Day to day variability in the transferrin receptor/ferritin index in female athletes
  1. R Stupnicki1,
  2. J Malczewska2,
  3. K Milde1,
  4. A C Hackney3
  1. 1Department of Biometry, Academy of Physical Education, Warsaw, Poland
  2. 2Department of Nutrition Physiology, Institute of Sport, Warsaw
  3. 3Applied Physiology Laboratory, University of North Carolina, Chapel Hill, NC, USA
  1. Correspondence to:
 Professor Stupnicki, Department of Biometry, Academy of Physical Education, Marymoncka 34, 00-968 Warsaw 45, Poland; 


Objective: To determine the within subject (day to day) variability for variables reflecting iron status (concentrations of ferritin and soluble transferrin receptor (sTfR), and the sTfR/logFerr index) in female athletes during a training camp, and in female control subjects.

Results: The error for ferritin concentration was nearly twice as high in athletes as in controls, that for sTfR concentration was identical in the two groups, and that for the sTfR/logFerr index was about 50% higher in athletes than in controls.

Conclusions: The within subject, day to day error for the sTfR/logFerr index computed from data recorded for untrained subjects cannot serve as a reference value for training athletes. When the sTfR/logFerr index is used to monitor iron stores in athletes, an error value of 0.20 should be used, because determination of the index after a few days of rest may not be feasible.

  • transferrin receptor
  • ferritin
  • iron status index
  • variability
  • female athletes
  • sTfR, soluble transferrin receptor
  • logFerr, log ferritin concentration

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.