Does intermittent hypoxia increase erythropoiesis in professional cyclists during a 3-week race?
In this study we examined the effects of intermittent hypoxia exposure (IHE) in a group of professional cyclists (n = 6; age 26 +/- 1 yr) competing in the 2001 Vuelta a España. After each daily stage, treated subjects received four 5-min bouts of normobaric IHE (mean O2 concentration of 12.6%, simulating a mean altitude of 4,000 m) interspersed with 5-min bouts of breathing hotel room air (normoxia) until completing a total IHE of 20-min duration. The primary outcome, compared to a control group of similar characteristics not receiving IHE (n = 5; age 25 +/- 1 yr), was the % increase in erythropoietin (Epo) from the beginning to the end of the Vuelta. Statistical analysis showed that Epo increase tended to be higher (p = 0.052) in the IHE group than in controls (37.4 +/- 5.8% vs. -4.4 +/- 19.5%, respectively). However IHE had no effect on reticulocytes or erythrocyte count (p > 0.05).
Villa
José G
JG
Dept. of Physical Education, Univ. of León, León, Spain.
Lucía
Alejandro
A
Marroyo
José A
JA
Avila
Concepción
C
Jiménez
Fernando
F
Garcia-López
Juan
J
Earnest
Conrad P
CP
Córdova
Alfredo
A
D000328:Adult; D000531:Altitude; D015308:Anaerobic Threshold / Q000502:physiology; D001642:Bicycling / Q000502:physiology*; D004906:Erythrocyte Count; D004920:Erythropoiesis / Q000502:physiology*; D004921:Erythropoietin / Q000097:blood; D005293:Ferritins / Q000097:blood; D006339:Heart Rate / Q000502:physiology; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000503:physiopathology*; D009747:Nutritional Physiological Phenomena / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D012156:Reticulocytes / Q000166:cytology; D013997:Time Factors
D006454:Hemoglobins; D004921:Erythropoietin; D005293:Ferritins