Thermoregulatory responses to cold water at different times of day

1999 ◽  
Vol 87 (1) ◽  
pp. 243-246 ◽  
Author(s):  
John W. Castellani ◽  
Andrew J. Young ◽  
James E. Kain ◽  
Michael N. Sawka

This study examined how time of day affects thermoregulation during cold-water immersion (CWI). It was hypothesized that the shivering and vasoconstrictor responses to CWI would differ at 0700 vs. 1500 because of lower initial core temperatures (Tcore) at 0700. Nine men were immersed (20°C, 2 h) at 0700 and 1500 on 2 days. No differences ( P > 0.05) between times were observed for metabolic heat production (M˙, 150 W ⋅ m−2), heat flow (250 W ⋅ m−2), mean skin temperature (T sk, 21°C), and the mean body temperature-change in M˙(ΔM˙) relationship. Rectal temperature (Tre) was higher ( P < 0.05) before (Δ = 0.4°C) and throughout CWI during 1500. The change in Tre was greater ( P < 0.05) at 1500 (−1.4°C) vs. 0700 (−1.2°C), likely because of the higher Tre-T skgradient (0.3°C) at 1500. These data indicate that shivering and vasoconstriction are not affected by time of day. These observations raise the possibility that CWI may increase the risk of hypothermia in the early morning because of a lower initial Tcore.

1992 ◽  
Vol 262 (4) ◽  
pp. R617-R623 ◽  
Author(s):  
K. B. Pandolf ◽  
R. W. Gange ◽  
W. A. Latzka ◽  
I. H. Blank ◽  
A. J. Young ◽  
...  

Thermoregulatory responses during cold-water immersion (water temperature 22 degrees C) were compared in 10 young men before as well as 24 h and 1 wk after twice the minimal erythemal dose of ultraviolet-B radiation that covered approximately 85% of the body surface area. After 10 min of seated rest in cold water, the mean exercised for 50 min on a cycle ergometer (approximately 51% of maximal aerobic power). Rectal temperature, regional and mean heat flow (hc), mean skin temperature from five sites, and hearrt rate were measured continuously for all volunteers while esophageal temperature was measured for six subjects. Venous blood samples were collected before and after cold water immersion. The mean skin temperature was higher (P less than 0.05) throughout the 60-min cold water exposure both 24 h and 1 wk after sunburn compared with before sunburn. Mean hc was higher (P less than 0.05) after 10 min resting immersion and during the first 10 min of exercise when 24 h postsunburn was compared with presunburn, with the difference attributed primarily to higher hc from the back and chest. While rectal temperature and heart rate did not differ between conditions, esophageal temperature before immersion and throughout the 60 min of cold water immersion was higher (P less than 0.05) when 24 h postsunburn was compared with presunburn. Plasma volume increased (P less than 0.05) after 1 wk postsunburn compared with presunburn, whereas plasma protein concentration was reduced (P less than 0.05). After exercise cortisol was greater (P less than 0.05) 24 h postsunburn compared with either presunburn or 1 wk postsunburn.(ABSTRACT TRUNCATED AT 250 WORDS)


2003 ◽  
Vol 95 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Peter Tikuisis

Certain previous studies suggest, as hypothesized herein, that heat balance (i.e., when heat loss is matched by heat production) is attained before stabilization of body temperatures during cold exposure. This phenomenon is explained through a theoretical analysis of heat distribution in the body applied to an experiment involving cold water immersion. Six healthy and fit men (mean ± SD of age = 37.5 ± 6.5 yr, height = 1.79 ± 0.07 m, mass = 81.8 ± 9.5 kg, body fat = 17.3 ± 4.2%, maximal O2 uptake = 46.9 ± 5.5 l/min) were immersed in water ranging from 16.4 to 24.1°C for up to 10 h. Core temperature (Tco) underwent an insignificant transient rise during the first hour of immersion, then declined steadily for several hours, although no subject's Tco reached 35°C. Despite the continued decrease in Tco, shivering had reached a steady state of ∼2 × resting metabolism. Heat debt peaked at 932 ± 334 kJ after 2 h of immersion, indicating the attainment of heat balance, but unexpectedly proceeded to decline at ∼48 kJ/h, indicating a recovery of mean body temperature. These observations were rationalized by introducing a third compartment of the body, comprising fat, connective tissue, muscle, and bone, between the core (viscera and vessels) and skin. Temperature change in this “mid region” can account for the incongruity between the body's heat debt and the changes in only the core and skin temperatures. The mid region temperature decreased by 3.7 ± 1.1°C at maximal heat debt and increased slowly thereafter. The reversal in heat debt might help explain why shivering drive failed to respond to a continued decrease in Tco, as shivering drive might be modulated by changes in body heat content.


2021 ◽  
Vol 9 (2) ◽  
pp. 118
Author(s):  
Dewi Sartika

Introduction: DOMS is a complaint of muscle pain experienced by athletes by exercising overloadedly. DOMS pain tolerance improvement was carried out with several interventions, in the form of a combination of stretching with cold water immersion, and stretching with contrast water immersion. The purpose of this research is to proving which comparison of physiotherapy interventions is better for DOMS pain tolerance improvement. Method: The research was carried out in the Ngurah Rai athletics field in Denpasar in January 2020, experimental in nature with a pretest and post test two group design. Samples were male athletes divided into two groups, each group consisting of 9 respondens. Group I was given a combination of stretching and cold water immersion, Group II was given a combination of stretching and water immersion in contrast. Cold water temperature is 10 ?C and warm water temperature 36-40 ?C. Pain tolerance value measured by sphygmomanometer placed on the calf. The higher the value mmHg, the higher the tolerance would be. Result: Results in Group I, the mean pain tolerance before intervention was 153 ± 7.76 (mmHg) and the mean after intervention (48 hours) 206 ± 8.32 (mmHg) with p = 0,000 (p <0.05). In Group II, the mean pain tolerance before intervention was 154 ± 8.35 (mmHg) and after intervention (48 hours) 188.4 ± 6.95 (mmHg) with a value of p = 0,000 (p <0.05). This showed a significant increase in pain tolerance in each group. Statistical tests conducted between the two groups also showed significant differences, with a result of p = 0,000 (p <0.05) where the value of pain tolerance in Group I was better than Group II. Conclusions: combination of stretching and cold water immersion is better than the combination of stretching and water immersion in contrast in reducing DOMS.     Keywords: Delayed onset muscle soreness; stretching; cold water; contrast water immersion.


Author(s):  
E. A. Adelusi ◽  
K. O. Olaoye ◽  
F. G. Adebawo

Cement bonded boards of 6 mm in thickness were produced from the mixture of Ceiba pentandra and Gmelina arborea sawdust. The influence of weight to weight proportion of C. pentandra and G. arborea blended at levels of 100:0, 75:25, 50:50, 25:75 and 0:100 in mass and mixing ratios of cement to wood 2:1 and 3:1 on Modulus of Rupture (MOR), Modulus of Elasticity (MOE) Water Absorption (WA) and Thickness Swelling (TS) properties of the experimental boards were examined for 24 h and 48 h immersion in cold water. The mean values for MOE and MOR were from 2479.50 to 5294.30 N/mm2 and 0.82 N/mm2 to 3.02 N/mm2 respectively, while the mean values for TS and WA after 24 h in cold water were from 0.53% to 7.35% and 14.8% to 52% respectively, whereas after 48 h in cold water immersion the mean values for TS and WA were from 2.37% to 10.48% and 16.5% to 69.5% respectively. It was observed that, increase in G. arborea (75%) to C. pentandra (25%) and mixing ratio 3:1 (cement/wood) was responsible for increase in MOR and MOE and decrease in TS and WA. The result shows that cement-bonded boards can be manufactured from Ceiba pentandra sawdust when mixed at certain blending proportion and ratio.


1999 ◽  
Vol 31 (Supplement) ◽  
pp. S309
Author(s):  
D. W. DeGroot ◽  
J. W. Castellani ◽  
A. J. Young ◽  
M. N. Sawka

1988 ◽  
Vol 64 (2) ◽  
pp. 719-727 ◽  
Author(s):  
P. Tikuisis ◽  
R. R. Gonzalez ◽  
K. B. Pandolf

The mathematical models of thermoregulation of Stolwijk and Hardy, and Montgomery were used to develop a model suitable for the simulation of human physiological responses to cold-water immersion. Data were obtained from experiments where 13 healthy male volunteers were totally immersed under resting and nude conditions for 1 h in water temperatures of 20 and 28 degrees C. At these temperatures, the mean measured rectal temperature (Tre) fell by approximately 0.9 and 0.5 degrees C, respectively, yet mean measured metabolic rate (M) rose by approximately 275 and 90 W for the low body fat group (n = 7) and 195 and 45 W for the moderate body fat group (n = 6). To predict the observed Tre and M values, the present model 1) included thermal inputs for shivering from the skin independent of their inclusion with the central temperature to account for the observed initial rapid rise in M, 2) determined a thermally neutral body temperature profile such that the measured and predicted initial values of Tre and M were matched, 3) confined the initial shivering to the trunk region to avoid an overly large predicted initial rate of rectal cooling, and 4) calculated the steady-state convective heat loss by assuming a zero heat storage in the skin compartment to circumvent the acute sensitivity to the small skin-water temperature difference when using conventional methods. The last three modifications are unique to thermoregulatory modeling.


1991 ◽  
Vol 71 (2) ◽  
pp. 432-437 ◽  
Author(s):  
W. K. Prusaczyk ◽  
M. N. Sawka

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.


2016 ◽  
Vol 11 (4) ◽  
pp. 480-488 ◽  
Author(s):  
Jamie Douglas ◽  
Daniel J. Plews ◽  
Phil J. Handcock ◽  
Nancy J. Rehrer

Purpose:To determine whether a facilitated recovery via cold-water immersion (CWI) after simulated rugby sevens would influence parasympathetic reactivation and repeated-sprint (RS) performance across 6 matches in a 2-d tournament.Methods:Ten male team-sport athletes completed 6 rugby sevens match simulations over 2 d with either postmatch passive recovery (PAS) or CWI in a randomized crossover design. Parasympathetic reactivation was determined via the natural logarithm of the square root of the mean of the sum of the squares of differences between adjacent R-R intervals (ln rMSSD). RS performance was calculated as time taken (s) to complete 6 × 30-m sprints within the first half of each match.Results:There were large increases in postintervention ln rMSSD between CWI and PAS after all matches (ES 90% CL: +1.13; ±0.21). Average heart rate (HR) during the RS performance task (HRAverage RS) was impaired from baseline from match 3 onward for both conditions. However, HRAverage RS was higher with CWI than with PAS (ES 90% CL: 0.58; ±0.58). Peak HR during the RS performance task (HRPeak RS) was similarly impaired from baseline for match 3 onward during PAS and for match 4 onward with CWI. HRPeak RS was very likely higher with CWI than with PAS (ES 90% CL: +0.80; ±0.56). No effects of match or condition were observed for RS performance, although there were moderate correlations between the changes in HRAverage RS (r 90% CL: –0.33; ±0.14), HRPeak RS (r 90% CL: –0.38; ±0.13), and RS performance.Conclusion:CWI facilitated cardiac parasympathetic reactivation after a simulated rugby sevens match. The decline in average and peak HR across matches was partially attenuated by CWI. This decline was moderately correlated with a reduction in RS performance.


2014 ◽  
Vol 222 (3) ◽  
pp. 165-170 ◽  
Author(s):  
Andrew L. Geers ◽  
Jason P. Rose ◽  
Stephanie L. Fowler ◽  
Jill A. Brown

Experiments have found that choosing between placebo analgesics can reduce pain more than being assigned a placebo analgesic. Because earlier research has shown prior experience moderates choice effects in other contexts, we tested whether prior experience with a pain stimulus moderates this placebo-choice association. Before a cold water pain task, participants were either told that an inert cream would reduce their pain or they were not told this information. Additionally, participants chose between one of two inert creams for the task or they were not given choice. Importantly, we also measured prior experience with cold water immersion. Individuals with prior cold water immersion experience tended to display greater placebo analgesia when given choice, whereas participants without this experience tended to display greater placebo analgesia without choice. Prior stimulus experience appears to moderate the effect of choice on placebo analgesia.


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