Background and objectives .– Left ventricular (LV) systolic function evaluated by LV ejection fraction (LVEF) is depressed after a long distance running for some studies, not for others. These discrepancies may be explained by a poor design of the protocols or a wrong interpretation of the results, since LVEF is load dependant. We aimed to evaluate twice LV systolic function in long distance runners using echo, before and immediately after a relay race (each athlete ran around 60 km), in 2008 and in 2009, using the same protocol.

Methods .– among 150 runners engaged in the 600-km Paris-Courchevel race (teams of 12 runners taking over from one another during four days and three nights), 22 male runners in 2008 (mean age 47.8 ± 5.5 years) and 23 male runners in 2009 (mean age 49.4 ± 7.7 years) accepted on a voluntary basis to have an echocardiography the day before the race (pre) and immediately after the end of the race (post). The same physician performed all the examinations pre (PD) and post (MS) in 2008 and 2009. Analysis was performed off-line blinded to clinical data. The following echo parameters were measured: LV fractional shortening (FS), LVEF using biplane Simpson method and end systolic stress (ESS). We also calculated a predicted FS according to ESS, and a ratio of observed/predicted FS (o/p ratio).

Results .– In 2008, pre LVEF (69.2 ± 4.9%) and pre FS (48.5 ± 4%) were significantly higher than post LVEF (65.3 ± 4.4%, P = 0.007) and post FS (42.6 ± 6.0%, P = 0.0005), but not in 2009 (pre LVEF 66.7 ± 5.3% and post LVEF 67.6 ± 5.4, P = 0.5) (pre FS 37.7 ± 4.6% and post FS 36.9 ± 5.5%, P = 0.3). However, end systolic stress (ESS), an afterload index, was not modified after the 2008 race (pre ESS 40.7 ± 6.2 103 dynes/cm ² , post ESS 43.9 ± 11.0 103 dynes/cm ² , P = 0.22), but it was in 2009 (pre ESS 52.0 ± 14.3 103 dynes/cm ² , post ESS 47.6 ± 11.9 103 dynes/cm ² , P = 0.03). O/p ratio was significantly lower after the race, both in 2008 (pre o/p 117.0 ± 8.4%; post o/p 104.1 ± 11.0%, P < 0.0001) and 2009 (pre o/p 98.2 ± 8.7%; post o/p 93.1 ± 11.5%, P = 0.03).

To conclude .– In the present study, LVEF decreased in runners after the race in 2008, but not in 2009. This could lead to an opposite conclusion concerning LV systolic function in long distance running. However, using adapted indices, sensitive to contractility and load, we found a comparable result with a significant and slight reduction of LV systolic function both in 2008 and 2009 immediately after a long distance running.