Cutaneous vascular responses to isometric handgrip exercise during local heating and hyperthermia

2005 ◽  
Vol 98 (6) ◽  
pp. 2011-2018 ◽  
Author(s):  
Gregg R. McCord ◽  
Christopher T. Minson
Keyword(s):  
Blood Flow ◽  
Heat Stress ◽  
Skin Blood Flow ◽  
Sweat Rate ◽  
Local Heating ◽  
Whole Body ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Hyperthermic Condition ◽  
Isometric Handgrip Exercise

The dramatic increase in skin blood flow and sweating observed during heat stress is mediated by poorly understood sympathetic cholinergic mechanisms. One theory suggests that a single sympathetic cholinergic nerve mediates cutaneous active vasodilation (AVD) and sweating via cotransmission of separate neurotransmitters, because AVD and sweating track temporally and directionally when activated during passive whole body heat stress. It has also been suggested that these responses are regulated independently, because cutaneous vascular conductance (CVC) has been shown to decrease, whereas sweat rate increases, during combined hyperthermia and isometric handgrip exercise. We tested the hypothesis that CVC decreases during isometric handgrip exercise if skin blood flow is elevated using local heating to levels similar to that induced by pronounced hyperthermia but that this does not occur at lower levels of skin blood flow. Subjects performed isometric handgrip exercise as CVC was elevated at selected sites to varying levels by local heating (which is independent of AVD) in thermoneutral and hyperthermic conditions. During thermoneutral isometric handgrip exercise, CVC decreased at sites in which blood flow was significantly elevated before exercise (−6.5 ± 1.8% of maximal CVC at 41°C and −10.5 ± 2.0% of maximal CVC at 43°C; P < 0.05 vs. preexercise). During isometric handgrip exercise in the hyperthermic condition, an observed decrease in CVC was associated with the level of CVC before exercise. Taken together, these findings argue against withdrawal of AVD to explain the decrease in CVC observed during isometric handgrip exercise in hyperthermic conditions.

scholarly journals Cutaneous vasomotor responses in boys and men

2018 ◽  
Vol 43 (10) ◽  
pp. 1019-1026 ◽  
Author(s):  
Gary J. Hodges ◽  
Matthew C. Mueller ◽  
Stephen S. Cheung ◽  
Bareket Falk
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Local Heating ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Local Skin ◽  
Doppler Flowmetry ◽  
Age Related ◽  
Isometric Handgrip Exercise ◽  
Underlying Mechanisms

Few studies have investigated skin blood flow in children and age-related differences in the underlying mechanisms. We examined mechanisms of skin blood flow responses to local heating, postocclusive reactive hyperaemia (PORH), and isometric handgrip exercise in adult and prepubescent males, hypothesizing that skin blood flow responses would be greater in children compared with adults. We measured skin blood flow in 12 boys (age, 9 ± 1 years) and 12 men (age, 21 ± 1 years) using laser-Doppler flowmetry at rest, in response to 3-min PORH, 2-min isometric handgrip exercise, and local skin heating to 39 °C (submaximal) and 44 °C (maximal). Using wavelet analysis we assessed endothelial, neural, and myogenic activities. At rest and in response to local heating to 39 °C, children had higher skin blood flow and endothelial activity compared with men (d ≥ 1.1, p < 0.001) and similar neurogenic and myogenic activities (d < 0.2, p > 0.05). Maximal responses to 44 °C local skin heating, PORH, and isometric handgrip exercise did not differ between boys and men (all d ≤ 0.2, p > 0.05). During PORH children demonstrated greater endothelial activity compared with men (d ≥ 0.6, p < 0.05); in contrast, men had higher neurogenic activity (d = 1.0, p < 0.01). During isometric handgrip exercise there were no differences in endothelial, neurogenic, and myogenic activities (d < 0.2, p > 0.3), with boys and men demonstrating similar increases in endothelial activity and decreases in myogenic activity (d ≥ 0.8, p < 0.05). These data suggest that boys experience greater levels of skin blood flow at rest and in response to submaximal local heating compared with men, while maximal responses appear to be similar. Additionally, endothelial mediators seem to contribute more to vasodilatation in boys than in men.

scholarly journals Neural and non-neural control of skin blood flow during isometric handgrip exercise in the heat stressed human

2009 ◽  
Vol 587 (9) ◽  
pp. 2101-2107 ◽  
Author(s):  
Manabu Shibasaki ◽  
Peter Rasmussen ◽  
Niels H. Secher ◽  
Craig G. Crandall
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Neural Control ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Isometric Handgrip Exercise

The effect of extracellular hyperosmolality on sweat rate during metaboreflex activation in passively heated young men

2021 ◽  
Author(s):  
Maura M. Rutherford ◽  
Ashley P. Akerman ◽  
Robert D. Meade ◽  
Sean R. Notley ◽  
Madison D. Schmidt ◽  
...  
Keyword(s):  
Sweat Rate ◽  
Nervous Activity ◽  
Maximum Voluntary Contraction ◽  
Young Men ◽  
Weighted Average ◽  
Whole Body ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Body Regions ◽  
Isometric Handgrip Exercise

Metaboreflex activation augments sweating during mild-to-moderate hyperthermia in euhydrated (isosmotic isovolemic) individuals. Recent work indicates that extracellular hyperosmolality may augment metaboreflex-mediated elevations in sympathetic nervous activity. Our primary objective was therefore to test the hypothesis that extracellular hyperosmolality would exacerbate metaboreflex-mediated increases in sweat rate. On two separate occasions, 12 young men (mean (SD): 25 (5) years) received a 90-min intravenous infusion of either 0.9% saline (isosmotic condition, ISO) or 3.0% saline (hyperosmotic condition, HYP), resulting in a post-infusion serum osmolality of 290 (3) and 301 (7) mOsm/kg, respectively. A whole-body water perfusion suit was then used to increase esophageal temperature by 0.8°C above resting. Participants then performed a metaboreflex activation protocol consisting of 90 s isometric handgrip exercise (40% of their pre-determined maximum voluntary contraction), followed by 150 s of brachial occlusion (trapping produced metabolites within the limb). Metaboreflex-induced sweating was quantified as the change in global sweat rate (from pre-isometric handgrip exercise to brachial occlusion), estimated as the surface area-weighted average of local sweat rate on the abdomen, axilla, chest, bicep, quadriceps, and calf, measured using ventilated capsules (3.8 cm2). We also explored whether this response differed between body regions. The change in global sweat rate due to metaboreflex activation was significantly greater in HYP compared to ISO (0.03 mg/min/cm2 [95% confidence interval: 0.00, 0.06]; p=0.047), but was not modulated by body region (site*condition interaction: p=0.679). These findings indicate that extracellular hyperosmolality augments metaboreflex-induced increases in global sweat rate, with no evidence for region-specific differences.

scholarly journals Effects of mode of exercise recovery on thermoregulatory and cardiovascular responses

2002 ◽  
Vol 93 (6) ◽  
pp. 1918-1924 ◽  
Author(s):  
Robert Carter ◽  
Thad E. Wilson ◽  
Donald E. Watenpaugh ◽  
Michael L. Smith ◽  
Craig G. Crandall
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Heat Dissipation ◽  
Sweat Rate ◽  
Local Heating ◽  
Cardiovascular Responses ◽  
Maximal Heart Rate ◽  
Exercise Recovery ◽  
Active Recovery ◽  
Arterial Blood

To identify the effects of exercise recovery mode on cutaneous vascular conductance (CVC) and sweat rate, eight healthy adults performed two 15-min bouts of upright cycle ergometry at 60% of maximal heart rate followed by either inactive or active (loadless pedaling) recovery. An index of CVC was calculated from the ratio of laser-Doppler flux to mean arterial pressure. CVC was then expressed as a percentage of maximum (%max) as determined from local heating. At 3 min postexercise, CVC was greater during active recovery (chest: 40 ± 3, forearm: 48 ± 3%max) compared with during inactive recovery (chest: 21 ± 2, forearm: 25 ± 4%max); all P < 0.05. Moreover, at the same time point sweat rate was greater during active recovery (chest: 0.47 ± 0.10, forearm: 0.46 ± 0.10 mg · cm−2 · min−1) compared with during inactive recovery (chest: 0.28 ± 0.10, forearm: 0.14 ± 0.20 mg · cm−2 · min−1); all P < 0.05. Mean arterial blood pressure, esophageal temperature, and skin temperature were not different between recovery modes. These data suggest that skin blood flow and sweat rate during recovery from exercise may be modulated by nonthermoregulatory mechanisms and that sustained elevations in skin blood flow and sweat rate during mild active recovery may be important for postexertional heat dissipation.

scholarly journals Impact Of Isometric Handgrip Exercise With Blood Flow Restriction On Interference Control And Affect

2021 ◽  
Vol 53 (8S) ◽  
pp. 311-311
Author(s):  
Yujiro Yamada ◽  
Jun Seob Song ◽  
Zachary W. Bell ◽  
Vickie Wong ◽  
Robert W. Spitz ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Flow Restriction ◽  
Interference Control ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Flow Restriction ◽  
Isometric Handgrip Exercise

Active cutaneous vasodilation in resting humans during mild heat stress

2005 ◽  
Vol 98 (3) ◽  
pp. 829-837 ◽  
Author(s):  
Yoshi-Ichiro Kamijo ◽  
Kichang Lee ◽  
Gary W. Mack
Keyword(s):  
Blood Flow ◽  
Heat Stress ◽  
Skin Temperature ◽  
Skin Blood Flow ◽  
Sweat Rate ◽  
Mean Skin Temperature ◽  
Local Skin ◽  
Mild Heat ◽  
Normal Core ◽  
Local Sweat Rate

The role of skin temperature in reflex control of the active cutaneous vasodilator system was examined in six subjects during mild graded heat stress imposed by perfusing water at 34, 36, 38, and 40°C through a tube-lined garment. Skin sympathetic nerve activity (SSNA) was recorded from the peroneal nerve with microneurography. While monitoring esophageal, mean skin, and local skin temperatures, we recorded skin blood flow at bretylium-treated and untreated skin sites by using laser-Doppler velocimetry and local sweat rate by using capacitance hygrometry on the dorsal foot. Cutaneous vascular conductance (CVC) was calculated by dividing skin blood flow by mean arterial pressure. Mild heat stress increased mean skin temperature by 0.2 or 0.3°C every stage, but esophageal and local skin temperature did not change during the first three stages. CVC at the bretylium tosylate-treated site (CVCBT) and sweat expulsion number increased at 38 and 40°C compared with 34°C ( P < 0.05); however, CVC at the untreated site did not change. SSNA increased at 40°C ( P < 0.05, different from 34°C). However, SSNA burst amplitude increased ( P < 0.05), whereas SSNA burst duration decreased ( P < 0.05), at the same time as we observed the increase in CVCBT and sweat expulsion number. These data support the hypothesis that the active vasodilator system is activated by changes in mean skin temperature, even at normal core temperature, and illustrate the intricate competition between active vasodilator and the vasoconstrictor system for control of skin blood flow during mild heat stress.

Heat stress attenuates the increase in arterial blood pressure during isometric handgrip exercise

2012 ◽  
Vol 113 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Konrad Binder ◽  
Daniel Gagnon ◽  
Aaron G. Lynn ◽  
Narihiko Kondo ◽  
Glen P. Kenny
Keyword(s):  
Blood Pressure ◽  
Heat Stress ◽  
Arterial Blood Pressure ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Arterial Blood ◽  
Isometric Handgrip Exercise

Impact of acute whole-body cold exposure with concurrent isometric handgrip exercise on aortic pressure waveform characteristics

2014 ◽  
Vol 114 (9) ◽  
pp. 1779-1787 ◽  
Author(s):  
Andrew P. Koutnik ◽  
Arturo Figueroa ◽  
Alexei Wong ◽  
Katherine J. Ramirez ◽  
Michael J. Ormsbee ◽  
...  
Keyword(s):  
Cold Exposure ◽  
Aortic Pressure ◽  
Whole Body ◽  
Pressure Waveform ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Isometric Handgrip Exercise

Mechanisms of control of skin blood flow during prolonged exercise in humans

1993 ◽  
Vol 265 (2) ◽  
pp. H562-H568 ◽  
Author(s):  
D. L. Kellogg ◽  
J. M. Johnson ◽  
W. L. Kenney ◽  
P. E. Pergola ◽  
W. A. Kosiba
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Sweat Rate ◽  
Bicycle Ergometer ◽  
Dew Point ◽  
Whole Body ◽  
Internal Temperature ◽  
Vasodilator Activity ◽  
Forearm Skin ◽  
Reduced Rate

Exercise in a warm environment raises internal temperature and leads to a rapid increase in skin blood flow (SkBF). As exercise continues, and internal temperature approaches 38 degrees C, the rate of rise of SkBF is markedly attenuated despite further significant increases in internal temperature. To find whether this attenuation is mediated by increased cutaneous active vasoconstrictor activity or by a reduced rate of rise of active vasodilator activity, each of 12 male subjects had 0.64 cm2 forearm skin sites iontophoretically treated with bretylium tosylate for selective local blockade of noradrenergic vasoconstrictor nerves. SkBF was monitored there and at adjacent untreated control sites by laser-Doppler blood flowmetry (LDF). Whole body skin temperature (Tsk) was controlled by water-perfused suits, and esophageal temperature (Tes) was monitored as an index of internal temperature. Mean arterial pressure (MAP) was monitored and cutaneous vascular conductance was calculated as LDF/MAP. Sweat rate was also monitored by dew point hygrometry in 11 subjects. Tsk was raised to 38 degrees C, after which subjects began 20-30 min of exercise on a bicycle ergometer. The rate of the initial rapid increase in SkBF with increasing Tes was not altered by bretylium treatment (P > 0.05 between sites). The attenuation of the rate of rise during the latter phase of exercise was not abolished by bretylium treatment (P > 0.05 between sites); instead, there was a trend for the attenuation to be enhanced at those sites. We conclude that the attenuated rate of rise of SkBF is due to limitation of active vasodilator activity and not due to increased vasoconstrictor tone.(ABSTRACT TRUNCATED AT 250 WORDS)

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