Cardiac output and performance during a marathon race in middle-aged recreational runners.
OBJECTIVE
Despite the increasing popularity of marathon running, there are no data on the responses of stroke volume (SV) and cardiac output (CO) to exercise in this context. We sought to establish whether marathon performance is associated with the ability to sustain high fractional use of maximal SV and CO (i.e, cardiac endurance) and/or CO, per meter (i.e., cardiac cost).


METHODS
We measured the SV, heart rate (HR), CO, and running speed of 14 recreational runners in an incremental, maximal laboratory test and then during a real marathon race (mean performance: 3 hr 30 min ± 45 min).


RESULTS
Our data revealed that HR, SV and CO were all in a high but submaximal steady state during the marathon (87.0 ± 1.6%, 77.2 ± 2.6%, and 68.7 ± 2.8% of maximal values, respectively). Marathon performance was inversely correlated with an upward drift in the CO/speed ratio (mL of CO × m(-1)) (r = -0.65, P < 0.01) and positively correlated with the runner's ability to complete the race at a high percentage of the speed at maximal SV (r = 0.83, P < 0.0002).


CONCLUSIONS
Our results showed that marathon performance is inversely correlated with cardiac cost and positively correlated with cardiac endurance. The CO response could be a benchmark for race performance in recreational marathon runners.
UBIAE, U902 INSERM, University of Evry-Val-D'Essonne, 91025 Evry, France. veronique.billat@wanadoo.fr
Véronique L
VL
Billat
Hélène
H
Petot
Morgan
M
Landrain
Renaud
R
Meilland
Jean Pierre
JP
Koralsztein
Laurence
L
Mille-Hamard
D000328:Adult; D000886:Anthropometry / Q000379:methods; D002302:Cardiac Output; D004576:Electromyography / Q000379:methods; D015444:Exercise; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology*
D010100:Oxygen