Irurtia, A. , Barrero, A. , Chaverri, D. , Carrasco, M., Iglesias, X., Rodríguez, F.A. Whole-body bioelectrical impedance vector migration for monitoring hydration status after an ultra-endurance triathlon. 18th Annual Congress of the European College of Sport Science, INEFC Barcelona. (Barcelona).

1. Irurtia, A. , Barrero, A. , Chaverri, D. , Carrasco, M.,
Iglesias, X., Rodríguez, F.A.
Whole-body bioelectrical impedance vector
migration for monitoring hydration status after an
ultra-endurance triathlon. 18th Annual Congress of
the European College of Sport Science, INEFC
Barcelona. (Barcelona).
xiglesias@gmail.com
Sport Sciences Research Group INEFC Barcelona
Grup de Recerca en Ciències de l'Esport INEFC Barcelona
Grup Consolidat (SGR 2014–1665 GRC)
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Av. de l’Estadi, 12-22
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@Recerca_INEFC

2. Introduction and aim
Monitoring hydration status after an ultra-endurance triathlon
(UET) emerges as a priority to safeguard both health and
physical performance of the growing tri-athletic population
(Knechtlet et al., 2008).
Bioelectrical impedance vector analysis (BIVA) is a
relative novel methodology for assessing the hydration status
(Lukaski & Piccoli, 2012).
This study aimed to provide the first comprehensive
characterization of the whole-body bioelectrical impedance
vector migration induced by an UET.
Materials and methods
11 well-trained non-professional ultra-endurance triathletes
(age 37.2±4.6 years, body mass 74.3±6.7 kg, height
174.0±6.0 cm, VO2max 67.5±4.2 ml/(kg·min) competed in an
UET (Extreme Man Salou-Costa Daurada 2011).
Body mass (BM) and bioelectrical variables (Z-Metrix®,
BioparHom Co, France) were obtained before, after, and 48 h
post-race. 50 kHz whole-body bioimpedance vectors were
analyzed by the resistance-reactance (R/Xc) graphic method
and Z mean values plotted (Piccoli et al., 1994). Hotelling’s T2
test was used to determine the difference in the complex
localized vector through the 95% confidence and tolerance
intervals obtained by BIVA.
WHOLE-BODY BIOELECTRICAL IMPEDANCE VECTOR MIGRATION FOR MONITORING HYDRATION STATUS
AFTER AN ULTRA-ENDURANCE TRIATHLON
Irurtia A.1, Barrero A.1, Chaverri D.1, Carrasco M.1,2, Iglesias X.1, Rodríguez F.A.1.
Results
Changes in BM (74.0±6.8 kg) post-race (69.6±6.5 kg,
-5.8±1.9% BM) and 48-h post-race (72.9±6,4 kg, -1.4±1.2%)
were significant (ANOVA, p=0.001).
BIVA showed Xc/h significant bioimpedance vector migration
patterns from pre (35.4±3.1Ω/m) to post-race (38.6±4.2 Ω/m,
p=0.05), from pre to 48-h post-race (31.8±2.7 Ω/m; p=0.03),
and from post-race to 48-h post-race (p=0.001). There were no
significant differences in R/h.
Discussion and conclusions
Body mass loss is consistent with previous UET studies
(Sharwood et al., 2004).
BIVA appears as a sensitive methodology for assessing
changes in body water (R) and body soft tissues (Xc) after an
ultra-endurance event. Bioimpedance vector showed a
migration characterized by a significant increase of reactance
(Xc) after the race and returning to (and even exceeding)
initial values thereafter.
More research is needed to improve our understanding of
bioimpedance vector migration patterns in ultra-endurance
competitive events.
References
Knechtlet B, Schwanke M, Knechtle P, Kohler G (2008). Br J Sport Med 42, 609-613.
Lukaski HC, Piccoli A (2012). Handbook of Anthropometry.Springer, 287-305.
Piccoli A, Rossi B, Pillon L, Bucciante G (1994). Kidney Int, 46, 534-539.
Piccoli A et al,. (1995). Am J Clin Nutr, 61:269-270.
Sharwood KA, Collins M, Goedecke JH, et al. (2004). Br J Sports Med, 38, 718-724.
Author’s e-mail: airurtia@gencat.cat
1 GRCE, INEFC-Barcelona, UB (Barcelona, Spain); 2 FCS Blanquerna, URL (Barcelona, Spain).
Pre-race
Post-race
48h Post-race
Male Italian reference
population