Influence of cardiac and hematological parameters on maximum oxygen uptake in healthy male adults

Falz R, Knaier R Hoppe S, Busse M

Summary

Falz R, Knaier R, Hoppe S, Busse M. Influence of cardiac and hematological parameters on maximal oxygen uptake in healthy male adults. Clinical Sports Medicine International (CSMI) 2014, 7(1): 1-8.

Purpose: The maximum oxygen uptake (VO2max) is depending on cardiac and hematological parameters. So far,  blood volume and cardiac output had rarely been measured. The aim of this paper was to investigate the influence of cardiac output and blood volume on VO2max in healthy subjects.

Materials and methods: 30 healthy males (age: 24±2 years, BMI: 24±2) performed an incremental exercise test (cycle ergometer, semi-recumbent) and a blood volume measurement (CO rebreathing method). The cardiopulmonary (impedance cardiography, spiro-ergometry) and metabolic response (blood lactate concentration) were monitored. A multiple linear regression (stepwise selection, backward elimination) and correlation analysis were carried out.

Results: VO2max did not correlate with the maximum cardiac output (r = .322), the maximum stroke volume (r = .286), the maximum heart rate (r = .207), the BV (r = .160), the arterio-venous oxygen difference (r = .198) or the tHb-mass (r = .346). Moderately significant correlations existed between relative VO2max and the cardiac output by body weight (r=.484) and the relative hemoglobin mass (r=.386). The maximal cardiac output was 23.3±3.3 l/min, the hemoglobin mass was 14.4±1.5 g/kg and the blood volume was 93±10 ml/kg. Differences in the cardiac and hematological parameters of subjects with the same maximum exercise load were observed.

Conclusion: A homogenous study group showed only small correlations between VO2max and exercise parameters. In subjects with the same power output, oxygen uptake seems either to be caused more by cardiac or by hematological factors. Reference values for maximum cardiac output and blood volume could improve the identification and classification of performance reserves of endurance athletes.

Keywords: Endurance performance, hemoglobin mass, cardiac output, oxygen consumption, body composition