Oxidative stress does not influence local sweat rate during high-intensity exercise

Exp Physiol. 2018 Feb 1;103(2):172-178. doi: 10.1113/EP086746. Epub 2017 Dec 20.


What is the central question of this study? We evaluated whether oxidative stress attenuates the contribution of nitric oxide to sweating during high-intensity exercise. What is the main finding and its importance? In contrast to our previous report of an oxidative stress-mediated reduction in nitric oxide-dependent cutaneous vasodilatation in this cohort during intense exercise, we demonstrated no influence of local ascorbate administration on the sweating response during moderate- (∼51% peak oxygen uptake) or high-intensity exercise (∼72% peak oxygen uptake). These new findings provide important mechanistic insight into how exercise-induced oxidative stress impacts sudomotor activity. Nitric oxide (NO)-dependent sweating is diminished during high- but not moderate-intensity exercise. We evaluated whether this impairment stems from increased oxidative stress during high-intensity exercise. On two separate days, 11 young (24 ± 4 years) men cycled in the heat (35°C) at a moderate [500 W; 52 ± 6% peak oxygen uptake (V̇O2 peak )] or high (700 W; 71 ± 5% V̇O2 peak ) rate of metabolic heat production. Each session included two 30 min exercise bouts separated by a 20 min recovery period. Local sweat rate was monitored at four forearm skin sites continuously perfused via intradermal microdialysis with the following: (i) lactated Ringer solution (Control); (ii) 10 mm ascorbate (Ascorbate; non-selective antioxidant); (iii) 10 mm NG -nitro-l-arginine methyl ester (l-NAME; NO synthase inhibitor); or (iv) 10 mm ascorbate plus 10 mm l-NAME (Ascorbate + l-NAME). During moderate exercise, sweat rate was attenuated at the l-NAME and Ascorbate + l-NAME sites (both ∼1.0 mg min-1 cm-2 ; all P < 0.05) but not at the Ascorbate site (∼1.1 mg min-1 cm-2 ; both P ≥ 0.28) in comparison to the Control site (∼1.1 mg min-1 cm-2 ). However, no differences were observed between treatment sites (∼1.4 mg min-1 cm-2 ; P = 0.75) during high-intensity exercise. We conclude that diminished NO-dependent sweating during intense exercise occurs independent of oxidative stress.

Keywords: hyperthermia; reactive oxygen species; sudomotor activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antioxidants / metabolism
  • Exercise / physiology*
  • Humans
  • Male
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Oxidative Stress* / drug effects
  • Oxidative Stress* / physiology
  • Regional Blood Flow / drug effects
  • Skin / drug effects
  • Skin / metabolism
  • Sweating / drug effects*
  • Young Adult


  • Antioxidants
  • NG-Nitroarginine Methyl Ester