scholarly journals Core Temperature Responses to Cold-Water Immersion Recovery: A Pooled-Data Analysis

2018 ◽  
Vol 13 (7) ◽  
pp. 917-925 ◽  
Author(s):  
Jessica M. Stephens ◽  
Ken Sharpe ◽  
Christopher Gore ◽  
Joanna Miller ◽  
Gary J. Slater ◽  
...  

Purpose: To examine the effect of postexercise cold-water immersion (CWI) protocols, compared with control (CON), on the magnitude and time course of core temperature (Tc) responses. Methods: Pooled-data analyses were used to examine the Tc responses of 157 subjects from previous postexercise CWI trials in the authors’ laboratories. CWI protocols varied with different combinations of temperature, duration, immersion depth, and mode (continuous vs intermittent). Tc was examined as a double difference (ΔΔTc), calculated as the change in Tc in CWI condition minus the corresponding change in CON. The effect of CWI on ΔΔTc was assessed using separate linear mixed models across 2 time components (component 1, immersion; component 2, postintervention). Results: Intermittent CWI resulted in a mean decrease in ΔΔTc that was 0.25°C (0.10°C) (estimate [SE]) greater than continuous CWI during the immersion component (P = .02). There was a significant effect of CWI temperature during the immersion component (P = .05), where reductions in water temperature of 1°C resulted in decreases in ΔΔTc of 0.03°C (0.01°C). Similarly, the effect of CWI duration was significant during the immersion component (P = .01), where every 1 min of immersion resulted in a decrease in ΔΔTc of 0.02°C (0.01°C). The peak difference in Tc between the CWI and CON interventions during the postimmersion component occurred at 60 min postintervention. Conclusions: Variations in CWI mode, duration, and temperature may have a significant effect on the extent of change in Tc. Careful consideration should be given to determine the optimal amount of core cooling before deciding which combination of protocol factors to prescribe.

1992 ◽  
Vol 73 (4) ◽  
pp. 1253-1258 ◽  
Author(s):  
G. G. Giesbrecht ◽  
G. K. Bristow

An attempt was made to demonstrate the importance of increased perfusion of cold tissue in core temperature afterdrop. Five male subjects were cooled twice in water (8 degrees C) for 53–80 min. They were then rewarmed by one of two methods (shivering thermogenesis or treadmill exercise) for another 40–65 min, after which they entered a warm bath (40 degrees C). Esophageal temperature (Tes) as well as thigh and calf muscle temperatures at three depths (1.5, 3.0, and 4.5 cm) were measured. Cold water immersion was terminated at Tes varying between 33.0 and 34.5 degrees C. For each subject this temperature was similar in both trials. The initial core temperature afterdrop was 58% greater during exercise (mean +/- SE, 0.65 +/- 0.10 degrees C) than shivering (0.41 +/- 0.06 degrees C) (P < 0.005). Within the first 5 min after subjects entered the warm bath the initial rate of rewarming (previously established during shivering or exercise, approximately 0.07 degrees C/min) decreased. The attenuation was 0.088 +/- 0.03 degrees C/min (P < 0.025) after shivering and 0.062 +/- 0.022 degrees C/min (P < 0.025) after exercise. In 4 of 10 trials (2 after shivering and 2 after exercise) a second afterdrop occurred during this period. We suggest that increased perfusion of cold tissue is one probable mechanism responsible for attenuation or reversal of the initial rewarming rate. These results have important implications for treatment of hypothermia victims, even when treatment commences long after removal from cold water.


2016 ◽  
Vol 41 (11) ◽  
pp. 1163-1170 ◽  
Author(s):  
Avina McCarthy ◽  
James Mulligan ◽  
Mikel Egaña

A brief cold water immersion between 2 continuous high-intensity exercise bouts improves the performance of the latter compared with passive recovery in the heat. We investigated if this effect is apparent in normothermic conditions (∼19 °C), employing an intermittent high-intensity exercise designed to reflect the work performed at the high-intensity domain in team sports. Fifteen young active men completed 2 exhaustive cycling protocols (Ex1 and Ex2: 12 min at 85% ventilatory threshold (VT) and then an intermittent exercise alternating 30-s at 40% peak power (Ppeak) and 30 s at 90% Ppeak to exhaustion) separated by 15 min of (i) passive rest, (ii) 5-min cold-water immersion at 8 °C, and (iii) 10-min cold-water immersion at 8 °C. Core temperature, heart rate, rates of perceived exertion, and oxygen uptake kinetics were not different during Ex1 among conditions. Time to failure during the intermittent exercise was significantly (P < 0.05) longer during Ex2 following the 5- and 10-min cold-water immersions (7.2 ± 3.5 min and 7.3 ± 3.3 min, respectively) compared with passive rest (5.8 ± 3.1 min). Core temperature, heart rate, and rates of perceived exertion were significantly (P < 0.05) lower during most periods of Ex2 after both cold-water immersions compared with passive rest. The time constant of phase II oxygen uptake response during the 85% VT bout of Ex2 was not different among the 3 conditions. A postexercise, 5- to 10-min cold-water immersion increases subsequent intermittent high-intensity exercise compared with passive rest in normothermia due, at least in part, to reductions in core temperature, circulatory strain, and effort perception.


2015 ◽  
Vol 50 (8) ◽  
pp. 792-799 ◽  
Author(s):  
Kevin C. Miller ◽  
Erik E. Swartz ◽  
Blaine C. Long

Context Current treatment recommendations for American football players with exertional heatstroke are to remove clothing and equipment and immerse the body in cold water. It is unknown if wearing a full American football uniform during cold-water immersion (CWI) impairs rectal temperature (Trec) cooling or exacerbates hypothermic afterdrop. Objective To determine the time to cool Trec from 39.5°C to 38.0°C while participants wore a full American football uniform or control uniform during CWI and to determine the uniform's effect on Trec recovery postimmersion. Design Crossover study. Setting Laboratory. Patients or Other Participants A total of 18 hydrated, physically active, unacclimated men (age = 22 ± 3 years, height = 178.8 ± 6.8 cm, mass = 82.3 ± 12.6 kg, body fat = 13% ± 4%, body surface area = 2.0 ± 0.2 m2). Intervention(s) Participants wore the control uniform (undergarments, shorts, crew socks, tennis shoes) or full uniform (control plus T-shirt; tennis shoes; jersey; game pants; padding over knees, thighs, and tailbone; helmet; and shoulder pads). They exercised (temperature approximately 40°C, relative humidity approximately 35%) until Trec reached 39.5°C. They removed their T-shirts and shoes and were then immersed in water (approximately 10°C) while wearing each uniform configuration; time to cool Trec to 38.0°C (in minutes) was recorded. We measured Trec (°C) every 5 minutes for 30 minutes after immersion. Main Outcome Measure(s) Time to cool from 39.5°C to 38.0°C and Trec. Results The Trec cooled to 38.0°C in 6.19 ± 2.02 minutes in full uniform and 8.49 ± 4.78 minutes in control uniform (t17 = −2.1, P = .03; effect size = 0.48) corresponding to cooling rates of 0.28°C·min−1 ± 0.12°C·min−1 in full uniform and 0.23°C·min−1 ± 0.11°C·min−1 in control uniform (t17 = 1.6, P = .07, effect size = 0.44). The Trec postimmersion recovery did not differ between conditions over time (F1,17 = 0.6, P = .59). Conclusions We speculate that higher skin temperatures before CWI, less shivering, and greater conductive cooling explained the faster cooling in full uniform. Cooling rates were considered ideal when the full uniform was worn during CWI, and wearing the full uniform did not cause a greater postimmersion hypothermic afterdrop. Clinicians may immerse football athletes with hyperthermia wearing a full uniform without concern for negatively affecting body-core cooling.


2003 ◽  
Vol 28 (8) ◽  
pp. 551-554
Author(s):  
Michael J. Durkot ◽  
Lawrence de Garavilla

1979 ◽  
Vol 57 (8) ◽  
pp. 860-865 ◽  
Author(s):  
G. R. Fox ◽  
J. S. Hayward ◽  
G. N. Hobson

The effects of alcohol on core cooling rates (rectal and tympanic), skin temperatures, and metabolic rate were determined for 10 subjects rendered hypothermic by immersion for 45 min in 10 °C water. Experiments were duplicated with and without a 20-min period of exercise at the beginning of cold water immersion. Measurements were continued during rewarming in a hot bath. With blood alcohol concentrations averaging 82 mg 100 mL−1, core cooling rates and changes in skin temperatures were insignificantly different from controls, even if the exercise period was imposed. Alcohol reduced shivering metabolic rate by an overall mean of 13%, insufficient to affect cooling rate. Alcohol had no effect on metabolic rate during exercise. During rewarming by hot bath, the amount of 'afterdrop' and rate of increase in core temperature were unaffected by alcohol. It was concluded that alcohol in a moderate dosage does not influence the rate of progress into hypothermia or subsequent, efficient rewarming. This emphasizes that the high incidence of alcohol involvement in water-related fatalities is due to alcohol potentiation of accidents rather than any direct effects on cold water survival, although very high doses of alcohol leading to unconsciousness would increase rate of progress into hypothermia.


1983 ◽  
Vol 54 (6) ◽  
pp. 1708-1716 ◽  
Author(s):  
Y. S. Park ◽  
D. W. Rennie ◽  
I. S. Lee ◽  
Y. D. Park ◽  
K. S. Paik ◽  
...  

Seasonal basal metabolic rates (BMR), critical water temperature (Tcw), maximal body insulations (Imax), and finger blood flow during hand immersion in 6 degrees C water (Q finger) were measured periodically during the course of a 3-yr longitudinal study (1980–1982) of modern Korean diving women (ama), who have been wearing wet suits since 1977 to avoid cold stress during work. Methods and protocols were identical to previous studies of cotton-suited ama from 1961–1974. The BMR of modern ama did not undergo seasonal fluctuation (1980–1981) and was within the DuBois standard and comparable to nondivers year around Tcw of ama was still reduced by 2–3 degrees C in 1980 but increased progressively to equal that of nondivers in 1982, when compared at comparable subcutaneous fat thickness (SFT). Since modern ama and nondivers have 2.4 times thicker SFT (i.e., 4–13 mm) than in 1962 the absolute Tcw is significantly reduced. Q finger of ama was also significantly lower than controls in 1980 but in 1981–1982 was identical to controls. Imax of modern ama was identical to controls of comparable SFT in 1980–1982. The time course of cold deacclimatization thus was BMR, 3 yr; Imax, 3 yr; Q finger, 4 yr; and Tcw, 5 yr. This longitudinal study provides further evidence that acclimatization to cold did at one time exist in these diving women.


2016 ◽  
Vol 51 (6) ◽  
pp. 500-501 ◽  
Author(s):  
Emma A. Nye ◽  
Jessica R. Edler ◽  
Lindsey E. Eberman ◽  
Kenneth E. Games

Reference: Zhang Y, Davis JK, Casa DJ, Bishop PA. Optimizing cold water immersion for exercise-induced hyperthermia: a meta-analysis. Med Sci Sports Exerc. 2015;47(11):2464−2472. Clinical Questions: Do optimal procedures exist for implementing cold-water immersion (CWI) that yields high cooling rates for hyperthermic individuals? Data Sources: One reviewer performed a literature search using PubMed and Web of Science. Search phrases were cold water immersion, forearm immersion, ice bath, ice water immersion, immersion, AND cooling. Study Selection: Studies were included based on the following criteria: (1) English language, (2) full-length articles published in peer-reviewed journals, (3) healthy adults subjected to exercise-induced hyperthermia, and (4) reporting of core temperature as 1 outcome measure. A total of 19 studies were analyzed. Data Extraction: Pre-immersion core temperature, immersion water temperature, ambient temperature, immersion duration, and immersion level were coded a priori for extraction. Data originally reported in graphical form were digitally converted to numeric values. Mean differences comparing the cooling rates of CWI with passive recovery, standard deviation of change from baseline core temperature, and within-subjects r were extracted. Two independent reviewers used the Physiotherapy Evidence Database (PEDro) scale to assess the risk of bias. Main Results: Cold-water immersion increased the cooling rate by 0.03°C/min (95% confidence interval [CI] = 0.03, 0.04°C/min) compared with passive recovery. Cooling rates were more effective when the pre-immersion core temperature was ≥38.6°C (P = .023), immersion water temperature was ≤10°C (P = .036), ambient temperature was ≥20°C (P = .013), or immersion duration was ≤10 minutes (P &lt; .001). Cooling rates for torso and limb immersion (mean difference = 0.04°C/min, 95% CI = 0.03, 0.06°C/min) were higher (P = .028) than those for forearm and hand immersion (mean difference = 0.01°C/min, 95% CI = −0.01, 0.04°C/min). Conclusions: Hyperthermic individuals were cooled twice as fast by CWI as by passive recovery. Therefore, the former method is the preferred choice when treating patients with exertional heat stroke. Water temperature should be &lt;10°C, with the torso and limbs immersed. Insufficient published evidence supports CWI of the forearms and hands.


1999 ◽  
Vol 13 (suppl a) ◽  
pp. 26A-31A ◽  
Author(s):  
Victor Plourde

Several autonomic, hormonal, behavioural and neuropeptidergic bodily responses to stressful stimuli have been described over the past few decades. Both animal models and human paradigms have been explored. It is acknowledged that stress modulates gastrointestinal (GI) motility through central mechanisms including corticotropin-releasing-factor. This process requires the integrity of autonomic neural pathways. It has become evident that the effects of stress on GI motility vary according to the stressful stimulus, its intensity, the animal species under study and the time course of the study. Recent evidence suggests that chronic or possibly permanent changes develop in enteric smooth muscle properties in response to stress. In animals, the most consistent findings include retardation of gastric emptying in response to various stressors; acceleration of gastric emptying upon cold stress, presumably through the secretion of brain thyroglobulin-hormone; acceleration of intestinal transit; and stimulation of colonic transit and fecal output. In humans, the cold water immersion test has been associated with an inhibition of gastric emptying, while labyrinthine stimulation induces the transition from postprandial to fasting motor patterns in the stomach and the small bowel. Psychological stress has been shown to induce a reduction in the number and amplitude of intestinal migrating motor complexes and to neither affect nor stimulate colonic motility. These various responses to stress are presumably attributed to the preferential activation of specific neuronal pathways under the influence of a given stimulus or its intensity. The significance of these findings and the directions of further studies are discussed.


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