Vascular volumes and hematology in male and female runners and cyclists.
To examine the hypothesis that foot-strike hemolysis alters vascular volumes and selected hematological properties is trained athletes, we have measured total blood volume (TBV), red cell volume (RCV) and plasma volume (PV) in cyclists (n = 21) and runners (n = 17) and compared them to those of untrained controls (n = 20). TBV (ml x kg(-1)) was calculated as the sum of RCV (ml x kg(-1)) and PV (ml x kg(-1)) obtained using 51Cr and 125I-labelled albumin, respectively. Hematological assessment was carried out using a Coulter counter. Peak aerobic power (VO2peak) was measured during progressive exercise to fatigue using both cycle and treadmill ergometry. RCV was 15% higher (P < 0.05) in male cyclists [35.4 (1.0), mean (SE); n = 12] and runners [35.3 (0.98); n = 9] compared to the controls [30.7 (0.92); n = 12]. Similar differences existed between the female cyclists [28.2 (2.1); n = 9] and runners [28.4 (1.0); n = 8] compared to the untrained controls [24.9 (1.4); n = 8]. For the male athletes, PV was between 19% (cyclists) and 28% (runners) higher (P < 0.05) in the trained athletes compared to the untrained controls. The differences in PV between the female groups were not significant. Although the males had a higher (P < 0.05) TBV, RCV and PV than the females, no differences between cyclists and runners were found for either gender. Mean cell volume was not different between the athletic groups. VO2peak (ml x kg(-1) x min(-1)) was higher (P < 0.05) in both male [68.4 (1.5)] and female [54.8 (2.1)] runners when compared to the untrained males [47.1 (1.0)] and females [40.5 (2.1)]. Although differences existed between the genders in VO2peak for both cyclists and runners, no differences were found between the athletic groups within a gender. Since the vascular volumes were not different between cyclists and runners for either the males or females, foot-strike hemolysis would not appear to have an effect on that parameter. The significant correlations (P < 0.05) found between VO2peak and RCV (r = 0.64 and 0.64) and TBV (r = 0.82 and 0.63) for the males and females, respectively, suggests a role for the vascular system in realizing a high aerobic power.
Department of Kinesiology, University of Waterloo, ON, Canada.
H J
HJ
Green
S
S
Carter
S
S
Grant
R
R
Tupling
G
G
Coates
M
M
Ali
D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D001642:Bicycling / Q000502:physiology*; D001808:Blood Vessels / Q000033:anatomy & histology* / Q000502:physiology*; D001810:Blood Volume / Q000502:physiology*; D002860:Chromium Radioisotopes; D004911:Erythrocyte Volume / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010953:Plasma Volume / Q000502:physiology; D012420:Running / Q000502:physiology*; D012711:Serum Albumin, Radio-Iodinated / Q000378:metabolism
D002860:Chromium Radioisotopes; D012711:Serum Albumin, Radio-Iodinated