_ _
355
Exercise Duration and Serum Erythropoietin Level
Introduction Erythropoietin (Epo) is an obligatory factor for erythroid cell growth (Spivak 1986) and, as such, is continuously present in plasma. Several reports (Cowart 1989; Murray 1989) suggest that Epo is now used illicitly in sports to boost athletic performance by increasing the blood oxygen-carrying capacity. Detection of Epo misusers requires improved knowledge in Epo physiology during exertion. In that sense, this study evaluates the influence of exercise duration on serum Epo concentrations.
pected from a direct exercise-induced effect of Epo at the kidney level (De Paoli Vitali, Guglielmini, Casoni, Vedovato, Gilli, Farinelli, Salvatorelli and Conconi 1988). Data presented clearly demonstrate that serum Epo is not directly influenced by long-lasting rectangular exercises. The slight (although unsignificant) increase in serum Epo observed after exercise is attributed to exercise-associated changes in plasma volume. Data also indicate an absence of significant variations in basal serum Epo level between well trained and untrained male subjects. References
Subjects and Methods Thirty one well trained (VO2max 60 ml-min -1.kg-1) young adult males gave their informed consent to participate in the study. Venous blood samples were collected in the morning before and after rectangular bicycle exercises (65% of VO2max) of various durations. In comparable conditions, resting control venous samples were also collected from 10 untrained young male adults. Serum Epo concentrations were measured by RIA (Incstar Corp., Stillwater, USA). Results and Discussion The present study was carried out to investigate the effect of exercise on serum Epo concentrations. Ninety minutes after initiation of exercise an increased serum Epo level could have been ex-
Cowart, V.S.:Physician and Sport Medicine 17:115-118 (1989) De Paoli Vitali, E., C. Guglielmini, I. Casoni, M. Vedovato, P. Gilli, A. Farinelli, G. Salvatorelli, F. Conconi: Int J. Sports Med. 9: 99-101 (1988) Murray, T. H.: Physician and Sport Medicine 17:39-42 (1989) Spivak, J. L.:Int. J. Cell Cloning 4:139-166(1986) Requests for reprints should be addressed to: Dr. R. Gareau Departement de Chimie-Biologie Universite du Quebec a Trois-Rivieres P. O. Box 500 Trois-Rivieres, Quebec (Canada G9A 5H7)
Table 1 Mean(±SEM) serum Epo values versus duration of exercise. Bicycle exercise Subjects Training
Number
Trained Trained Trained Trained
5 10 10 6
Untrained
10
Intensity (%V02max) 65 65 65 65
Horm. metab. Res. 23 (1991) 355 © Georg Thieme Verlag Stuttgart -New York
Duration (minutes) 30 90 120 180
Serum Epo (mU/ml) Submaximal exercise after before 17.4±1.2 16.9 ±1.7 16.5 ±2.1 17.2 ±1.4
19.5 ±2.1 19.7±1.9 18.4±1.5 21.3 ± 1.3
18.3± 1.6 (resting)
Received: 2 Oct. 1990
Accepted: 13 March 1991
Downloaded by: National University of Singapore. Copyrighted material.
R. Gareau , C. Caron and G. R. Brisson2 1 Universite du Quebec a Trois-Rivieres, Trois-Rivieres 2 INRS-Sante, Pointe-Claire, Quebec, Canada
355
Exercise Duration and Serum Erythropoietin Level
Introduction Erythropoietin (Epo) is an obligatory factor for erythroid cell growth (Spivak 1986) and, as such, is continuously present in plasma. Several reports (Cowart 1989; Murray 1989) suggest that Epo is now used illicitly in sports to boost athletic performance by increasing the blood oxygen-carrying capacity. Detection of Epo misusers requires improved knowledge in Epo physiology during exertion. In that sense, this study evaluates the influence of exercise duration on serum Epo concentrations.
pected from a direct exercise-induced effect of Epo at the kidney level (De Paoli Vitali, Guglielmini, Casoni, Vedovato, Gilli, Farinelli, Salvatorelli and Conconi 1988). Data presented clearly demonstrate that serum Epo is not directly influenced by long-lasting rectangular exercises. The slight (although unsignificant) increase in serum Epo observed after exercise is attributed to exercise-associated changes in plasma volume. Data also indicate an absence of significant variations in basal serum Epo level between well trained and untrained male subjects. References
Subjects and Methods Thirty one well trained (VO2max 60 ml-min -1.kg-1) young adult males gave their informed consent to participate in the study. Venous blood samples were collected in the morning before and after rectangular bicycle exercises (65% of VO2max) of various durations. In comparable conditions, resting control venous samples were also collected from 10 untrained young male adults. Serum Epo concentrations were measured by RIA (Incstar Corp., Stillwater, USA). Results and Discussion The present study was carried out to investigate the effect of exercise on serum Epo concentrations. Ninety minutes after initiation of exercise an increased serum Epo level could have been ex-
Cowart, V.S.:Physician and Sport Medicine 17:115-118 (1989) De Paoli Vitali, E., C. Guglielmini, I. Casoni, M. Vedovato, P. Gilli, A. Farinelli, G. Salvatorelli, F. Conconi: Int J. Sports Med. 9: 99-101 (1988) Murray, T. H.: Physician and Sport Medicine 17:39-42 (1989) Spivak, J. L.:Int. J. Cell Cloning 4:139-166(1986) Requests for reprints should be addressed to: Dr. R. Gareau Departement de Chimie-Biologie Universite du Quebec a Trois-Rivieres P. O. Box 500 Trois-Rivieres, Quebec (Canada G9A 5H7)
Table 1 Mean(±SEM) serum Epo values versus duration of exercise. Bicycle exercise Subjects Training
Number
Trained Trained Trained Trained
5 10 10 6
Untrained
10
Intensity (%V02max) 65 65 65 65
Horm. metab. Res. 23 (1991) 355 © Georg Thieme Verlag Stuttgart -New York
Duration (minutes) 30 90 120 180
Serum Epo (mU/ml) Submaximal exercise after before 17.4±1.2 16.9 ±1.7 16.5 ±2.1 17.2 ±1.4
19.5 ±2.1 19.7±1.9 18.4±1.5 21.3 ± 1.3
18.3± 1.6 (resting)
Received: 2 Oct. 1990
Accepted: 13 March 1991
Downloaded by: National University of Singapore. Copyrighted material.
R. Gareau , C. Caron and G. R. Brisson2 1 Universite du Quebec a Trois-Rivieres, Trois-Rivieres 2 INRS-Sante, Pointe-Claire, Quebec, Canada
