Iron Status in Cyclists During High-Intensity Interval Training and Recovery

Abstract

The purpose of this study was to examine the effects of a 6 week high-intensity interval training (HIT) program, followed by 2 weeks recovery, on iron status in cyclists. Eleven male collegiate cyclists (21.8 ± 0.8 yr, 71.4 ± 2.2 kg, and 8.6 ± 0.9 % body fat) participated in a 6 week cycle training program that consisted of 5 days of high intensity interval and endurance training per week. Hematocrit (Hct), hemoglobin (Hb), red blood cell (RBC) count, serum iron, serum ferritin, and total iron binding capacity (TIBC) were analyzed from venous blood samples taken at baseline (B), and each week following interval training (T1-T6) and recovery (R1-R2). Dietary intakes including iron were monitored weekly. The dependent variables were analyzed by repeated measures ANOVA (p < 0.05). RBC count, Hb and Hct were significantly decreased compared to baseline at T3. Serum iron did not change significantly. Serum ferritin decreased significantly from 55.9 ± 9.7 at B to 42.2 ± 8.0 ng × ml^-1 at T5 and remained depressed at T6, R1 and R2. TIBC was significantly increased above baseline at T3, T4, T6, R1 and R2. These results suggest that 6 weeks of high-intensity interval training can reduce iron stores. It is possible that this reduction in iron stores over time could adversely affect aerobic cycling performance.

Serum ferritin - hemoglobin - total iron binding capacity - exercise

References

• 1 Ashenden M J, Martin D T, Dobson G P, Mackintosh C, Hahn A G. Serum ferritin and anemia in trained female athletes.  Int J Sports Nutr. 1998;  8 223-229
• 2 Balaban E P, Cox J V, Snell P, Vaughan R H, Frenkel E P. The frequency of anemia and iron deficiency in the runner.  Med Sci Sports Exerc. 1989;  21 643-648
• 3 Banister E W, Hamilton C L. Variations in iron status with fatigue modelled from training in female distance runners.  Eur J Appl Physiol. 1985;  54 16-23
• 4 Beard J, Tobin B. Iron status and exercise.  Amer J Clin Nut. 2000;  72 594-597
• 5 Bon Gray BA, Telford R D, Weidemann W J. The effect of intense interval exercise on iron status parameters in trained men.  Med Sci Sport Exerc. 2000;  25 778-782
• 6 Celsing F, Ekblom B. Anemia causes a relative decrease in blood lactate concentration during exercise.  Eur J Appl Physiol. 1986;  55 74-78
• 7 Celsing F, Nyström J, Pihlstedt P, Werner B, Ekblom B. Effect of long-term anemia and retransfusion on central circulation during exercise.  J Appl Physiol. 1986;  61 1358-1362
• 8 Dill B D, Costill C L. Calculation of percentage changes I volumes of blood, plasma, and red cells in dehydration.  J Appl Physiol. 1974;  23 247-248
• 9 Davidson R JL, Robertson J D, Galea G, Maughan R J. Hematological changes associated with marathon running.  Int J Sports Med. 1987;  8 19-25
• 10 Diehl D M, Lohman T G, Smith S C, Kertzer R. Effects of physical training and competition on the iron status of female field hockey players.  Int J Sports Med. 1986;  7 264-270
• 11 Eichner E R. Sports anemia, iron supplementation, and blood doping.  Med Sci Sports Exerc. 1992;  24 S315-S318
• 12 Friedmann B, Weller E, Mairbaurl H, Bartsch P. The effects of iron repletion on blood volume and performance capacity in young athletes.  Med Sci Sports Exerc. 2001;  33 741-746
• 13 Fry R W, Morton A R, Keast D. Overtraining in athletes: An update.  Sports Med. 1991;  12 32-65
• 14 Gimenez M, Uffholtz H, Paysant P, Belleville F, Nabet P. Serum iron and transferrin during an exhaustive session of interval training.  Eur J Appl Physiol. 1988;  57 154-158
• 15 Haymes E M. Trace minerals and exercise. In: Wolinsky I (ed) Nutrition in Exercise and Sport. New York; CRC Press 1998 3 rd ed, Chapter 8
• 16 Kaiser V, Janssen G ME, van Wersch J WJ. Effects of training on red blood cell parameters and plasma ferritin: A transverse and a longitudinal approach.  Int J Sports Med. 1989;  10 S169-S175
• 17 Klingshirn L A, Pate R, Bourque S P, Davis J M, Sargent R G. Effect of iron supplementation on endurance capacity in iron-depleted female runners.  Med Sci Sports Exerc. 1989;  24 819-824
• 18 LaManca J J, Haymes E M. Effects of iron repletion on V˙O₂max, endurance and blood lactate in women.  Med Sci Sport Exerc. 1993;  25 1386-1392
• 19 Lindsey F H, Hawley J A, Myburgh K H, Schomer H H, Noakes T D, Dennis S C. Improved athletic performance in highly trained cyclists after interval training.  Med Sci Sports Exerc. 1996;  28 1427-1434
• 20 Magazanik A, Weinstein Y, Dlin R A, Derin M, Schwartzman S. Iron deficiency caused by 7 weeks of intensive physical exercise.  Eur J Appl Physiol. 1988;  57 198-202
• 21 Malczewska J, Szczepanska B, Stupnicki R, Sendecki W. The assessment of frequency of iron deficiency in athletes from the transferrin receptor-ferritin index.  Int J Sport Nut Exerc Metab. 2001;  11 42-52
• 22 Malczewska J, Blach W, Stupnicki R. The effects of physical exercise on the concentrations of ferritin and transferrin receptors in plasma of female judoists.  Int J Sport Med. 2000;  21 175-179
• 23 Newhouse I J, Clement D B. Iron status in athletes: An update.  Sports Med. 1988;  5 337-352
• 24 Newhouse I J, Clement D B, Taunton J E, McKenzie D C. The effects of prelatent/latent iron deficiency on physical work capacity.  Med Sci Sports Sci. 1989;  21 263-268
• 25 Pizza F X, Flynn M G, Boone J B, Rodriguez-Zayas J R, Andres F F. Serum haptoglobin and ferritin during a competitive running and swimming season.  Int J Sports Med. 1997;  18 233-237
• 26 Powell P D, Tucker A. Iron supplementation and running performance in female cross-country runners.  Int J Sports Med. 1991;  15 462-467
• 27 Ratzin-Jackson C G, Sharkey B J. Altitude, training and human performance.  Sports Med. 1988;  6 279-284
• 28 Robertson J D, Maughan R J, Davidson R JL. Changes in red cell density and related indices in response to distance running.  Eur J Appl Physiol. 1988;  57 264-269
• 29 Robertson J D, Maughan R J, Milne A C, Davidson R JL. Hematological status of male runners in relation to the extent of physical training.  Int J Sport Nutr. 1992;  2 366-375
• 30 Schmidt W, Maassen N, Trost F, Boening D. Training induced effects on blood volume, erythrocyte turnover and haemoglobin oxygen binding properties.  Eur J Appl Physiol. 1988;  57 490-498
• 31 Schmidt W, Maassen N, Tegtbur U, Braumann K M. Changes in plasma volume and red cell formation after a marathon competition.  Eur J Appl Physiol. 1989;  58 453-458
• 32 Stepto N K, Hawley J A, Dennis S C, Hopkins W G. Effects of different interval-training programs on cycling time-trail performance.  Med Sci Sport Exerc. 1999;  31 736-741
• 33 Szygula Z. Erythrocytic system under the influence of physical exercise and training.  Sports Med. 1990;  10 181-197