The increase in hydric volume is associated to contractile impairment in the calf after the world's most extreme mountain ultra-marathon.
BACKGROUND
Studies have recently focused on the effect of running a mountain ultra-marathon (MUM) and their results show muscular inflammation, damage and force loss. However, the link between peripheral oedema and muscle force loss is not really established. We tested the hypothesis that, after a MUM, lower leg muscles' swelling could be associated with muscle force loss. The knee extensor (KE) and the plantar flexor (PF) muscles' contractile function was measured by supramaximal electrical stimulations, potentiated low- and high-frequency doublets (PS10 and PS100) of the KE and the PF were measured by transcutaneous electrical nerve stimulation and bioimpedance was used to assess body composition in the runners (n = 11) before (Pre) and after (Post) the MUM and compared with the controls (n = 8).


RESULTS
The maximal voluntary contraction of the KE and the PF significantly decreased by 20 % Post-MUM in the runners. Hydration of the non-fat mass (NF-Hyd) and extracellular water volume (Ve) were increased by 12 % Post-MUM (p < 0.001) in the runners. Calf circumference (+2 %, p < 0.05) was also increased. Significant relationships were found for percentage increases in Ve and NF-Hyd with percentage decrease in PS10 of the PF (r = -0.68 and r = -0.70, p < 0.05) and with percentage increase of calf circumference (r = 0.72 and r = 0.73, p < 0.05) in the runners.


CONCLUSIONS
The present study suggests that increases in circumference and in hydric volume are associated to contractile impairment in the calf in ultra-marathon runners.
Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne, Geopolis, 1015 Lausanne, Switzerland ; Health Research Unit, School of Health Sciences, University of Applied Sciences Western Switzerland, Lausanne, Switzerland.
Damien
D
Vitiello
Health Research Unit, School of Health Sciences, University of Applied Sciences Western Switzerland, Lausanne, Switzerland.
Francis
F
Degache
Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne, Geopolis, 1015 Lausanne, Switzerland ; Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
Jonas J
JJ
Saugy
Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne, Geopolis, 1015 Lausanne, Switzerland ; Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
Nicolas
N
Place
Faculty of Motor Sciences, University of Verona, Verona, Italy.
Federico
F
Schena
Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne, Geopolis, 1015 Lausanne, Switzerland ; Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
Grégoire P
GP
Millet
Inflammation; Muscle force loss; Oedema; Ultra-endurance; Ultra-running