The effect of local repeated passive heating and handgrip exercise on reflex cutaneous vascular and sudomotor responses to whole-body heat stress

David A Low,Helen Jones,Danielle Turner,Thomas G Bailey,N Timothy Cable

doi:10.1186/2046-7648-4-s1-a119

David A Low, Helen Jones + Show 3 more

Open Access

https://doi.org/10.1186/2046-7648-4-s1-a119

Copy DOI

Abstract

Enhancements in local cutaneous microvascular function are dependent upon elevations in both skin blood flow and temperature with repeated episodes of shear stress a key mechanism [1,2]. The mechanisms cause chronic sudomotor adaptations are not entirely clear however. Acute alterations in local cutaneous blood flow and temperature independently modify local sweat rate [3], possibly via variations in shear stress affecting endothelial nitric oxide release, suggesting that changes in skin blood flow and/or temperature may modulate sudomotor adaptations. It is also unclear as to the effects of localised thermal/hemodynamic interventions on neural cutaneous vascular and sudomotor responses. The aim of this study was to therefore compare the effects of repeated local forearm passive heating (that increases skin temperature and skin blood flow) and local handgrip exercise (that increases skin blood flow only) on sudomotor responses to whole-body heat stress.

Highlights

Enhancements in local cutaneous microvascular function are dependent upon elevations in both skin blood flow and temperature with repeated episodes of shear stress a key mechanism [1,2]
Fourteen healthy young males [age 21(3) y] underwent 8 weeks of local passive heating on 1 arm and intermittent handgrip exercise (33% MVC; 30 contractions per min) training with the other for 3 sessions per week for 30 minutes each in thermoneutral conditions
Observed enhancements in microvascular function with local passive heating, in contrast to the present findings, were evident during local, e.g., non-neural, heating [1]. These results suggest that 1) any effects of local interventions aimed at the cutaneous vasculature do not result in changes in the neural cutaneous vascular and sudomotor responses to whole-body passive heating, and, 2) a combination of repeated elevations in internal temperature and sweating are required for sudomotor adaptations

Summary

Introduction

Enhancements in local cutaneous microvascular function are dependent upon elevations in both skin blood flow and temperature with repeated episodes of shear stress a key mechanism [1,2]. Acute alterations in local cutaneous blood flow and temperature independently modify local sweat rate [3], possibly via variations in shear stress affecting endothelial nitric oxide release, suggesting that changes in skin blood flow and/or temperature may modulate sudomotor adaptations. It is unclear as to the effects of localised thermal/hemodynamic interventions on neural cutaneous vascular and sudomotor responses. The aim of this study was to compare the effects of repeated local forearm passive heating (that increases skin temperature and skin blood flow) and local handgrip exercise (that increases skin blood flow only) on sudomotor responses to whole-body heat stress

Objectives

Methods

Results

Conclusion