Attenuation of the cutaneous blood flow response during combined exercise and heat stress

Eur J Appl Physiol Occup Physiol. 1994;69(4):367-9. doi: 10.1007/BF00392045.


Skin blood flow (SkBF) was measured in six male subjects using laser-Doppler velocimetry, with zero-gradient auditory canal temperature (Tac) used as an index of body core temperature (Tc). Subjects performed incremental, upright cycling commencing at 40% peak power (Wpeak: 10 min), increasing every 4 min by 5% Wpeak thereafter. Trials were conducted in hot (ambient temperature (Ta) 36.7 +/- 0.2 degree C, relative humidity (rh) 46.1 +/- 3.2%; mean +/- S.D.), and neutral environments (Ta 19.6 +/- 0.3 degree C, rh 50.2 +/- 1.4%). SkBF increased with Tac in all subjects. Attenuation of SkBF occurred at the same Tac, relative SkBF and cardiac frequency (fc) between environments, but at a lower exercise intensity (40.8 +/- 0.8% versus 55.8 +/- 3.0% Wpeak) in the hot environment (p < 0.05). Data indicate that Tc thresholds for SkBF attenuation may exist. However, it is suggested that attenuation thresholds coincided with a reduced central blood volume, which may occur at a critical level of cutaneous blood pooling.

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Blood Flow Velocity / physiology*
  • Blood Pressure
  • Body Temperature
  • Cardiac Output
  • Exercise / physiology*
  • Hot Temperature / adverse effects*
  • Humans
  • Laser-Doppler Flowmetry
  • Male
  • Regional Blood Flow
  • Skin / blood supply*
  • Skin Physiological Phenomena
  • Stress, Physiological / physiopathology*
  • Vasodilation