PMID- 29483882
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20200930
IS  - 1664-042X (Print)
IS  - 1664-042X (Electronic)
IS  - 1664-042X (Linking)
VI  - 9
DP  - 2018
TI  - Fluid Metabolism in Athletes Running Seven Marathons in Seven Consecutive Days.
PG  - 91
LID - 10.3389/fphys.2018.00091 [doi]
LID - 91
AB  - Purpose: Hypohydration and hyperhydration are significant disorders of fluid 
      metabolism in endurance performance; however, little relevant data exist 
      regarding multi-stage endurance activities. The aim of the present study was to 
      examine the effect of running seven marathons in 7 consecutive days on selected 
      anthropometric, hematological and biochemical characteristics with an emphasis on 
      hydration status. Methods: Participants included 6 women and 20 men (age 42.6 +/- 
      6.2 years). Data was collected before day 1 (B(1)) and after day 1 (A(1)), 4 
      (A(4)), and 7 (A(7)). Results: The average marathon race time was 4:44 h:min 
      (ranging from 3:09 - 6:19 h:min). Plasma sodium, plasma potassium and urine 
      sodium were maintained during the race. Body mass (p < 0.001, eta(2) = 0.501), body 
      fat (p < 0.001, eta(2) = 0.572) and hematocrit (p < 0.001, eta(2) = 0.358) decreased. 
      Plasma osmolality (Posm) (p < 0.001, eta(2) = 0.416), urine osmolality (Uosm) (p < 
      0.001, eta(2) = 0.465), urine potassium (p < 0.001, eta(2) = 0.507), urine specific 
      gravity (Usg) (p < 0.001, eta(2) = 0.540), plasma urea (PUN) (p < 0.001, eta(2) = 
      0.586), urine urea (UUN) (p < 0.001, eta(2) = 0.532) and transtubular potassium 
      gradient (p < 0.001, eta(2) = 0.560) increased at A(1), A(4), and A(7) vs. B(1). 
      Posm correlated with PUN at A(1) (r = 0.59, p = 0.001) and A(4) (r = 0.58, p = 
      0.002). The reported post-race fluid intake was 0.5 +/- 0.2 L/h and it correlated 
      negatively with plasma [Na(+)] (r = -0.42, p = 0.007) at A(4) and (r = -0.50, p = 
      0.009) at A(7). Uosm was associated with UUN at A(1) (r = 0.80, p < 0.001), at 
      A(4) (r = 0.81, p < 0.001) and at A(7) (r = 0.86, p < 0.001) and with Usg (r = 
      0.71, p < 0.001) at A(1), (r = 0.52, p = 0.006) at A(4) and (r = 0.46, p = 0.02) 
      at A(7). Conclusions: Despite the decrease in body mass, fluid and electrolyte 
      balance was maintained with no decrease in plasma volume after running seven 
      marathons in seven consecutive days. Current findings support the hypothesis that 
      body mass changes do not reflect changes in the hydration status during prolonged 
      exercise.
FAU - Chlibkova, Daniela
AU  - Chlibkova D
AD  - Centre of Sports Activities, Brno University of Technology, Brno, Czechia.
FAU - Nikolaidis, Pantelis T
AU  - Nikolaidis PT
AD  - Exercise Physiology Laboratory, Nikaia, Greece.
FAU - Rosemann, Thomas
AU  - Rosemann T
AD  - Institute of Primary Care, University of Zurich, Zurich, Switzerland.
FAU - Knechtle, Beat
AU  - Knechtle B
AD  - Institute of Primary Care, University of Zurich, Zurich, Switzerland.
AD  - Medbase St. Gallen Am Vadianplatz, St. Gallen, Switzerland.
FAU - Bednar, Josef
AU  - Bednar J
AD  - Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czechia.
LA  - eng
PT  - Journal Article
DEP - 20180212
PL  - Switzerland
TA  - Front Physiol
JT  - Frontiers in physiology
JID - 101549006
PMC - PMC5816349
OTO - NOTNLM
OT  - endurance
OT  - hydration status
OT  - multi-stage marathon
OT  - running
OT  - sodium
EDAT- 2018/02/28 06:00
MHDA- 2018/02/28 06:01
PMCR- 2018/02/12
CRDT- 2018/02/28 06:00
PHST- 2017/11/12 00:00 [received]
PHST- 2018/01/26 00:00 [accepted]
PHST- 2018/02/28 06:00 [entrez]
PHST- 2018/02/28 06:00 [pubmed]
PHST- 2018/02/28 06:01 [medline]
PHST- 2018/02/12 00:00 [pmc-release]
AID - 10.3389/fphys.2018.00091 [doi]
PST - epublish
SO  - Front Physiol. 2018 Feb 12;9:91. doi: 10.3389/fphys.2018.00091. eCollection 2018.