European Journal of Applied Physiology

, Volume 113, Issue 6, pp 1499–1509

Haemodynamic responses to dehydration in the resting and exercising human leg

  • James Pearson
  • Kameljit K. Kalsi
  • Eric J. Stöhr
  • David A. Low
  • Horace Barker
  • Leena Ali
  • José González-Alonso
Original Article

DOI: 10.1007/s00421-012-2579-2

Cite this article as:
Pearson, J., Kalsi, K.K., Stöhr, E.J. et al. Eur J Appl Physiol (2013) 113: 1499. doi:10.1007/s00421-012-2579-2

Abstract

Dehydration and hyperthermia reduces leg blood flow (LBF), cardiac output (\( \dot{Q} \)) and arterial pressure during whole-body exercise. It is unknown whether the reductions in blood flow are associated with dehydration-induced alterations in arterial blood oxygen content (CaO2) and O2-dependent signalling. This study investigated the impact of dehydration and concomitant alterations in CaO2 upon LBF and \( \dot{Q} \). Haemodynamics, arterial and femoral venous blood parameters and plasma [ATP] were measured at rest and during one-legged knee-extensor exercise in 7 males in four conditions: (1) control, (2) mild dehydration, (3) moderate dehydration, and (4) rehydration. Relative to control, CaO2 and LBF increased with dehydration at rest and during exercise (CaO2: from 199 ± 1 to 208 ± 2, and 202 ± 2 to 210 ± 2 ml L−1 and LBF: from 0.38 ± 0.04 to 0.77 ± 0.09, and 1.64 ± 0.09 to 1.88 ± 0.1 L min−1, respectively). Similarly, \( \dot{Q} \) was unchanged or increased with dehydration at rest and during exercise, whereas arterial and leg perfusion pressures declined. Following rehydration, CaO2 declined (to 193 ± 2 mL L−1) but LBF remained elevated. Alterations in LBF were unrelated to CaO2 (r2 = 0.13–0.27, P = 0.48–0.64) and plasma [ATP]. These findings suggest dehydration and concomitant alterations in CaO2 do not compromise LBF despite reductions in plasma [ATP]. While an additive or synergistic effect cannot be excluded, reductions in LBF during exercise with dehydration may not necessarily be associated with alterations in CaO2 and/or intravascular [ATP].

Keywords

Dehydration Leg blood flow Cardiovascular control Rehydration 

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • James Pearson
    • 1
    • 3
  • Kameljit K. Kalsi
    • 1
  • Eric J. Stöhr
    • 1
    • 4
  • David A. Low
    • 1
    • 5
  • Horace Barker
    • 2
  • Leena Ali
    • 2
  • José González-Alonso
    • 1
  1. 1.Centre for Sports Medicine and Human PerformanceBrunel UniversityUxbridgeUK
  2. 2.Department of AnaestheticsEaling Hospital, NHS TrustSouthallUK
  3. 3.School of Health SciencesCardiff Metropolitan UniversityCardiffUK
  4. 4.Cardiff School of SportCardiff Metropolitan UniversityCardiffUK
  5. 5.Neurovascular and Autonomic Medicine Unit, Clinical Neurosciences, Faculty of Medicine St. Mary’s Hospital, Imperial College LondonLondonUK

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