Muscle mechanical characteristics in fatigue and recovery from a marathon race in highly trained runners.

The aim of the present study was to examine muscle mechanical characteristics before and after a marathon race. Eight elite runners underwent a pre-test 1 week before the marathon and post-tests 30 min, two and five-day-post-marathon. Actual marathon race performance was 2:34:40 +/- 0:04:13. Energy expenditure at marathon pace (EE(Mpace)) was elevated 4% post-marathon (pre: 4,465 +/- 91 vs. post 4,638 +/- 91 J kg bodyweight(-1) km(-1), P < 0.05), but was lowered by 6 and 9.5% two- and five-day-post-marathon compared to EE(Mpace) pre-marathon. Countermovement jump (CMJ) power decreased 13% post-marathon (pre: 21.5 +/- 0.9 vs. post: 18.9 +/- 1.2 W kg(-1); P < 0.05) and remained depressed two- (18%) and five-day (12%) post-marathon. CMJ force was unaltered across all four tests occasions. Knee extensor and plantar flexor maximal voluntary contraction (MVC) decreased from 176.6 +/- 9.5 to 136.7 +/- 16.8 Nm and 144.9 +/- 8.7 to 119.2 +/- 15.1 Nm post-marathon corresponding to 22 and 17%, respectively (P < 0.05). No significant changes were detected in evoked contractile parameters, except a 25% increase in force at 5 Hz, and low frequency fatigue was not observed. In conclusion, leg muscle power decreased acutely post-marathon race and recovered very slowly. The post-marathon increase in EE(Mpace) might be attributed to a reduction in stretch shortening cycle efficiency. Finally, since MVC was reduced after the marathon race without any marked changes in evoked muscle contractile properties, the strength fatigue experienced by the subjects in this study seems to be related to central rather than peripheral mechanisms.