Effect of cold acclimation on neuromuscular function of the hand

2006 ◽  
Vol 31 (4) ◽  
pp. 480-481
Author(s):  
Carla L.M. Geurts
Keyword(s):  
Cold Stress ◽  
Cold Acclimation ◽  
Cold Exposure ◽  
Force Control ◽  
Cold Water ◽  
Water Immersion ◽  
Temperature Response ◽  
Neuromuscular Function ◽  
Cold Water Immersion ◽  
Hand Temperature

The research in this thesis investigated the effects of cold stress on neuromuscular function with the main focus on cold acclimation. In total, 6 studies, 1 field study and 5 experiments, were conducted. The field study showed that during manual work in cold weather, finger and hand temperature can drop to levels that may impair manual function. The first 2 experiments were conducted to investigate the effect of acute local cold stress on force control and to investigate the effect of cold-induced vasodilatation (CIVD) on neuromuscular function. In experiment 1, it was found that cooling of the hand in 10 °C cold water for 10 min did not improve force control, although neuromuscular function was significantly impaired after cooling. In experiment 2, cold-induced vasodilatation, occurring after 20 min of 8 °C cold-water immersion of the hand, was confined to the finger tip and had no effect on the temperature of the first dorsal interosseus (FDI) muscle or its neuromuscular function. A series of cold acclimation studies was conducted to investigate the effect of repeated cold-water hand immersions on neuromuscular function. In these experiments, neuromuscular function was tested before and after 2–3 weeks of daily hand immersion in 8 °C cold water for 30 min. In experiment 3, it was found that 3 weeks of cold-water immersion resulted in a decrease in minimum and mean index finger temperature and CIVD was attenuated. Neuromuscular function was not affected by this change in temperature response. In experiment 4, one hand was exposed daily to cold water and compared with the opposite control hand. Blood plasma catecholamine concentrations were increased after 2 weeks in the cold-exposed hand, but no changes in temperature response or neuromuscular function were found after repeated cold exposure. Thermal comfort after 30 min of cold-water immersion significantly improved after repeated cold exposure causing a discrepancy between actual and perceived temperature and it was suggested that this may impose a greater risk of cold injury owing to a change in behavioural thermoregulation. In the last experiment, core temperature was elevated by bicycling at a submaximal level during the cold hand immersion. Exercise had a direct effect on the temperature response during cold-water immersion, decreasing the minimum FDI temperature and slowing down the deteriorating effect of cold on neuromuscular function; however, exercise showed was no effect on local cold acclimation. It is concluded that local repeated cold exposures may improve finger and hand temperature and subjective thermal ratings, but that these changes are too small to improve neuromuscular function. The best remedy to maintain manual function is to limit or avoid cold stress as much as possible. If sufficient protection of the hands is impossible, core heating through exercise or passive heating may be a solution.

scholarly journals Seven days of cold acclimation substantially reduces shivering intensity and increases nonshivering thermogenesis in adult humans

2019 ◽  
Vol 126 (6) ◽  
pp. 1598-1606 ◽  
Author(s):  
Kyle Gordon ◽  
Denis P. Blondin ◽  
Brian J. Friesen ◽  
Hans Christian Tingelstad ◽  
Glen P. Kenny ◽  
...  
Keyword(s):  
Cold Acclimation ◽  
Core Temperature ◽  
Heat Production ◽  
Cold Exposure ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Metabolic Changes ◽  
Whole Body ◽  
Nonshivering Thermogenesis

Daily compensable cold exposure in humans reduces shivering by ~20% without changing total heat production, partly by increasing brown adipose tissue thermogenic capacity and activity. Although acclimation and acclimatization studies have long suggested that daily reductions in core temperature are essential to elicit significant metabolic changes in response to repeated cold exposure, this has never directly been demonstrated. The aim of the present study is to determine whether daily cold-water immersion, resulting in a significant fall in core temperature, can further reduce shivering intensity during mild acute cold exposure. Seven men underwent 1 h of daily cold-water immersion (14°C) for seven consecutive days. Immediately before and following the acclimation protocol, participants underwent a mild cold exposure using a novel skin temperature clamping cold exposure protocol to elicit the same thermogenic rate between trials. Metabolic heat production, shivering intensity, muscle recruitment pattern, and thermal sensation were measured throughout these experimental sessions. Uncompensable cold acclimation reduced total shivering intensity by 36% ( P = 0.003), without affecting whole body heat production, double what was previously shown from a 4-wk mild acclimation. This implies that nonshivering thermogenesis increased to supplement the reduction in the thermogenic contribution of shivering. As fuel selection did not change following the 7-day cold acclimation, we suggest that the nonshivering mechanism recruited must rely on a similar fuel mixture to produce this heat. The more significant reductions in shivering intensity compared with a longer mild cold acclimation suggest important differential metabolic responses, resulting from an uncompensable compared with compensable cold acclimation. NEW & NOTEWORTHY Several decades of research have been dedicated to reducing the presence of shivering during cold exposure. The present study aims to determine whether as little as seven consecutive days of cold-water immersion is sufficient to reduce shivering and increase nonshivering thermogenesis. We provide evidence that whole body nonshivering thermogenesis can be increased to offset a reduction in shivering activity to maintain endogenous heat production. This demonstrates that short, but intense cold stimulation can elicit rapid metabolic changes in humans, thereby improving our comfort and ability to perform various motor tasks in the cold. Further research is required to determine the nonshivering processes that are upregulated within this short time period.

Free fatty acid availability and temperature regulation in cold water

1989 ◽  
Vol 67 (6) ◽  
pp. 2466-2472 ◽  
Author(s):  
L. Martineau ◽  
I. Jacobs
Keyword(s):  
Cold Exposure ◽  
Temperature Regulation ◽  
Cold Water ◽  
Vastus Lateralis ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Glucose Levels ◽  
Plasma Ffa ◽  
Glycogen Utilization ◽  
Male Subjects

The purpose of this study was to investigate whether a reduced availability of plasma free fatty acids (FFA) would impair human temperature regulation during cold exposure. Seven seminude male subjects were immersed on two occasions in 18 degrees C water for 90 min or until their rectal temperature (Tre) decreased to 35.5 degrees C. The immersion occurred after 2 h of intermittent oral ingestion of either nicotinic acid (NIC) or a placebo (PLAC). Plasma FFA levels immediately before the immersion were significantly lower in NIC (87 +/- 15 mumol/l) than in PLAC (655 +/- 116 mumol/l, P less than 0.05). Although FFA levels increased by 73% in NIC during the immersion (P less than 0.05), they remained significantly lower than in PLAC (151 +/- 19 vs. 716 +/- 74 mumol/l, P less than 0.05) throughout the immersion. Muscle glycogen concentrations in the vastus lateralis decreased after cold water immersion in both trials (P less than 0.05), but the rate of glycogen utilization was similar, averaging 1.00 +/- 0.27 mmol glucose unit.kg dry muscle-1.min-1). Plasma glucose levels were significantly reduced after immersion in both trials (P less than 0.05), this decrease being greater in NIC (1.3 +/- 0.2 mmol/l) than in PLAC (0.7 +/- 0.1 mmol/l, P less than 0.05). O2 uptake increased to 3.8 +/- 0.3 times preimmersion values in both trials (P less than 0.05). Mean respiratory exchange ratio (RER) immediately before the immersion was greater in NIC (0.87 +/- 0.02) than in PLAC (0.77 +/- 0.01, P less than 0.05). Cold exposure increased RER in PLAC but not in NIC.(ABSTRACT TRUNCATED AT 250 WORDS)

Local cold acclimation during exercise and its effect on neuromuscular function of the hand

2006 ◽  
Vol 31 (6) ◽  
pp. 717-725 ◽  
Author(s):  
Carla L.M. Geurts ◽  
Gordon G. Sleivert ◽  
Stephen S. Cheung
Keyword(s):  
Cold Acclimation ◽  
Core Temperature ◽  
Cold Exposure ◽  
Water Immersion ◽  
Neuromuscular Function ◽  
Control Group ◽  
Male Age ◽  
Group 4 ◽  
Custom Made ◽  
Significant Difference

Most acclimation research is performed on resting individuals, whereas in real life, cold exposure is often accompanied by physical activity. We examined the effects of 2 weeks of repeated cold exposure of the hand with or without an elevated core temperature from exercise on neuromuscular function of the first dorsal interosseus (FDI) muscle and manual performance of the hand. The experimental group (4 female, 6 male; age, 25.1 ± 6.9 y) cooled their hands in 8 °C water for 30 min daily while cycling (50% of heart rate reserve); the control group (4 female, 4 male; age, 25.1 ± 5.7 y) remained still. Manual function testing consisted of tactile sensitivity, grip strength, manual dexterity, and evoked twitch force in a custom-made myograph. Thermal sensation, skin temperature of index finger (Tif) and hand (Tfdi), as well as rectal temperature (Tre), were recorded daily. Tre increased significantly during bicycling, by 0.6 ± 0.2 °C. Minimal Tif and Tfdi of the groups combined increased significantly during exposure days from 8.7 ± 0.7 °C and 12.4 ± 2.8 °C to 10.1 ± 1.3 °C and 15.0 ± 3.0 °C, respectively (p = 0.04), with no significant difference between groups. Thermal ratings improved significantly on exposure days. Manual function was impaired with cooling, but with no significant difference between groups or across time. Deterioration of twitch characteristics with cooling did not change with repeated cold exposure. Although the increasing core temperature during cold water immersion changed the acute temperature response and thermal ratings, it had no effect on local cold acclimation or manual function.

scholarly journals Digital Temperature Response to a Cold Water Immersion in Various Nerve Injuries

1980 ◽  
Vol 2 (3) ◽  
pp. 339-345
Author(s):  
Katsumi SUZUKI ◽  
Masateru IJICHI ◽  
Minoru KONDO ◽  
Sadao TAKAHASHI ◽  
Isao YAGJ
Keyword(s):  
Cold Water ◽  
Water Immersion ◽  
Temperature Response ◽  
Cold Water Immersion ◽  
Nerve Injuries

Impairment of exercise performance following cold water immersion is not attenuated after 7 days of cold acclimation

2018 ◽  
Vol 118 (6) ◽  
pp. 1189-1197 ◽  
Author(s):  
Douglas M. Jones ◽  
Bart Roelands ◽  
Stephen P. Bailey ◽  
Michael J. Buono ◽  
Romain Meeusen
Keyword(s):  
Cold Acclimation ◽  
Exercise Performance ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion

Thermoregulation during cold water immersion is unimpaired by low muscle glycogen levels

1989 ◽  
Vol 66 (4) ◽  
pp. 1809-1816 ◽  
Author(s):  
A. J. Young ◽  
M. N. Sawka ◽  
P. D. Neufer ◽  
S. R. Muza ◽  
E. W. Askew ◽  
...  
Keyword(s):  
Cold Stress ◽  
Muscle Glycogen ◽  
Cold Water ◽  
Vastus Lateralis ◽  
Water Immersion ◽  
Substantial Reduction ◽  
Lactate Concentration ◽  
Plasma Free Fatty Acid ◽  
Cold Water Immersion ◽  
Vastus Lateralis Muscle

This investigation studied the importance of muscle glycogen levels for body temperature regulation during cold stress. Physiological responses of eight euglycemic males were measured while they rested in cold (18 degrees C, stirred) water on two separate occasions. The trials followed a 3-day program of diet and exercise manipulation designed to produce either high (HMG) or low (LMG) preimmersion glycogen levels in the muscles of the legs, arms, and upper torso. Preimmersion vastus lateralis muscle glycogen concentrations were lower during the LMG trial (144 +/- 14 mmol glucose/kg dry tissue) than the HMG trial (543 +/- 53 mmol glucose/kg dry tissue). There were no significant differences between the two trials in shivering as reflected by aerobic metabolic rate or in the amount of body cooling as reflected by changes in rectal temperature during the immersions. Postimmersion muscle glycogen levels remained unchanged from preimmersion levels in both trials. Small but significant increases in plasma glucose and lactate concentration occurred during both immersions. Plasma glycerol increased during immersion in the LMG trial but not in the HMG trial. Plasma free fatty acid concentration increased during both immersion trials, but the change was apparent sooner in the LMG immersion. It was concluded that thermoregulatory responses of moderately lean and fatter individuals exposed to cold stress were not impaired by a substantial reduction in the muscle glycogen levels of several major skeletal muscle groups. Furthermore, the data suggest that, depending on the intensity of shivering, other metabolic substrates are available to enable muscle glycogen to be spared.

Effects of pyridostigmine bromide on human thermoregulation during cold water immersion

1991 ◽  
Vol 71 (2) ◽  
pp. 432-437 ◽  
Author(s):  
W. K. Prusaczyk ◽  
M. N. Sawka
Keyword(s):  
Metabolic Rate ◽  
Cold Stress ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Pyridostigmine Bromide ◽  
Cholinesterase Inhibition ◽  
Mean Body Temperature ◽  
Ventilatory Volume ◽  
Human Thermoregulation

This study examined the effects of an oral 30-mg dose of pyridostigmine bromide (PYR) on thermoregulatory and physiological responses of men undergoing cold stress. Six men were immersed in cold water (20 degrees C) for up to 180 min on two occasions, once each 2 h after ingestion of PYR and 2 h after ingestion of a placebo. With PRY, erythrocyte cholinesterase inhibition was 33 +/- 12% (SD) 110 min postingestion (10 min preimmersion) and 30 +/- 7% at termination of exposure (mean 117 min). Percent cholinesterase inhibition was significantly related to lean body mass (r = -0.91, P less than 0.01). Abdominal discomfort caused termination in three of six PYR experiments but in none of the control experiments (mean exposure time 142 min). During immersion, metabolic rate, ventilatory volume, and respiratory rate increased significantly (P less than 0.05) over preimmersion levels and metabolic rate increased with duration of immersion (P less than 0.01) in both treatment but did not differ between conditions. PYR had no significant effect on rectal temperature, mean body temperature, thermal sensations, heart rate, plasma cortisol, or change in plasma volume. It was concluded that a 30-mg dose of PYR does not increase an individual's susceptibility to hypothermia during cold water immersion; however, in combination with cold stress, PYR may result in marked abdominal cramping and limit cold tolerance.

Human thermoregulatory responses to cold air are altered by repeated cold water immersion

1986 ◽  
Vol 60 (5) ◽  
pp. 1542-1548 ◽  
Author(s):  
A. J. Young ◽  
S. R. Muza ◽  
M. N. Sawka ◽  
R. R. Gonzalez ◽  
K. B. Pandolf
Keyword(s):  
Cold Acclimation ◽  
Cold Water ◽  
Water Immersion ◽  
Stress Test ◽  
Cold Water Immersion ◽  
Plasma Norepinephrine ◽  
Cold Air ◽  
Thermoregulatory Responses ◽  
Before And After ◽  
C 30

The effects of repeated cold water immersion on thermoregulatory responses to cold air were studied in seven males. A cold air stress test (CAST) was performed before and after completion of an acclimation program consisting of daily 90-min cold (18 degrees C) water immersion, repeated 5 times/wk for 5 consecutive wk. The CAST consisted of resting 30 min in a comfortable [24 degrees C, 30% relative humidity (rh)] environment followed by 90 min in cold (5 degrees C, 30% rh) air. Pre- and postacclimation, metabolism (M) increased (P less than 0.01) by 85% during the first 10 min of CAST and thereafter rose slowly. After acclimation, M was lower (P less than 0.02) at 10 min of CAST compared with before, but by 30 min M was the same. Therefore, shivering onset may have been delayed following acclimation. After acclimation, rectal temperature (Tre) was lower (P less than 0.01) before and during CAST, and the drop in Tre during CAST was greater (P less than 0.01) than before. Mean weighted skin temperature (Tsk) was lower (P less than 0.01) following acclimation than before, and acclimation resulted in a larger (P less than 0.02) Tre-to-Tsk gradient. Plasma norepinephrine increased during both CAST (P less than 0.002), but the increase was larger (P less than 0.004) following acclimation. These findings suggest that repeated cold water immersion stimulates development of true cold acclimation in humans as opposed to habituation. The cold acclimation produced appears to be of the insulative type.

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