Thermoregulatory model for immersion of humans in cold water

1988 ◽  
Vol 64 (2) ◽  
pp. 719-727 ◽  
Author(s):  
P. Tikuisis ◽  
R. R. Gonzalez ◽  
K. B. Pandolf
Keyword(s):  
Body Fat ◽  
Present Model ◽  
Heat Storage ◽  
Initial Rate ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Central Temperature ◽  
Thermoregulatory Model ◽  
The Mean

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.

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
Keyword(s):  
Cold Water ◽  
Water Immersion ◽  
Early Morning ◽  
Cold Water Immersion ◽  
Time Of Day ◽  
Mean Skin Temperature ◽  
Mean Body Temperature ◽  
Metabolic Heat ◽  
Body Temperature Change ◽  
The Mean

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.

A second postcooling afterdrop: more evidence for a convective mechanism

1992 ◽  
Vol 73 (4) ◽  
pp. 1253-1258 ◽  
Author(s):  
G. G. Giesbrecht ◽  
G. K. Bristow
Keyword(s):  
Core Temperature ◽  
Initial Rate ◽  
Treadmill Exercise ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Probable Mechanism ◽  
Warm Bath ◽  
Male Subjects ◽  
Shivering Thermogenesis

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.

scholarly journals Cold-Water Immersion Cooling Rates in Football Linemen and Cross-Country Runners With Exercise-Induced Hyperthermia

2017 ◽  
Vol 52 (10) ◽  
pp. 902-909 ◽  
Author(s):  
Sandra Fowkes Godek ◽  
Katherine E. Morrison ◽  
Gregory Scullin
Keyword(s):  
Cooling Rate ◽  
Body Mass ◽  
Body Fat ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Physical Characteristics ◽  
Cooling Rates ◽  
Cross Country ◽  
Cross Country Runners

Context:  Ideal and acceptable cooling rates in hyperthermic athletes have been established in average-sized participants. Football linemen (FBs) have a small body surface area (BSA)-to-mass ratio compared with smaller athletes, which hinders heat dissipation. Objective:  To determine cooling rates using cold-water immersion in hyperthermic FBs and cross-country runners (CCs). Design:  Cohort study. Setting:  Controlled university laboratory. Patients or Other Participants:  Nine FBs (age = 21.7 ± 1.7 years, height = 188.7 ± 4 cm, mass = 128.1 ± 18 kg, body fat = 28.9% ± 7.1%, lean body mass [LBM] = 86.9 ± 19 kg, BSA = 2.54 ± 0.13 m2, BSA/mass = 201 ± 21.3 cm2/kg, and BSA/LBM = 276.4 ± 19.7 cm2/kg) and 7 CCs (age = 20 ± 1.8 years, height = 176 ± 4.1 cm, mass = 68.7 ± 6.5 kg, body fat = 10.2% ± 1.6%, LBM = 61.7 ± 5.3 kg, BSA = 1.84 ± 0.1 m2, BSA/mass = 268.3 ± 11.7 cm2/kg, and BSA/LBM = 298.4 ± 11.7 cm2/kg). Intervention(s):  Participants ingested an intestinal sensor, exercised in a climatic chamber (39°C, 40% relative humidity) until either target core temperature (Tgi) was 39.5°C or volitional exhaustion was reached, and were immediately immersed in a 10°C circulated bath until Tgi declined to 37.5°C. A general linear model repeated-measures analysis of variance and independent t tests were calculated, with P &lt; .05. Main Outcome Measure(s):  Physical characteristics, maximal Tgi, time to reach 37.5°C, and cooling rate. Results:  Physical characteristics were different between groups. No differences existed in environmental measures or maximal Tgi (FBs = 39.12°C ± 0.39°C, CCs = 39.38°C ± 0.19°C; P = .12). Cooling times required to reach 37.5°C (FBs = 11.4 ± 4 minutes, CCs = 7.7 ± 0.06 minutes; P &lt; .002) and therefore cooling rates (FBs = 0.156°C·min−1 ± 0.06°C·min−1, CCs = .255°C·min−1 ± 0.05°C·min−1; P &lt; .002) were different. Strong correlations were found between cooling rate and body mass (r = −0.76, P &lt; .001), total BSA (r = −0.74, P &lt; .001), BSA/mass (r = 0.73, P &lt; .001), LBM/mass (r = 0.72, P &lt; .002), and LBM (r = −0.72, P &lt; .002). Conclusions:  With cold-water immersion, the cooling rate in CCs (0.255°C·min−1) was greater than in FBs (0.156°C·min−1); however, both were considered ideal (≥0.155°C·min−1). Athletic trainers should realize that it likely takes considerably longer to cool large hyperthermic American-football players (&gt;11 minutes) than smaller, leaner athletes (7.7 minutes). Cooling rates varied widely from 0.332°C·min−1 in a small runner to only 0.101°C·min−1 in a lineman, supporting the use of rectal temperature for monitoring during cooling.

scholarly journals COMBINATION OF STRETCHING WITH IMMERSION SYSTEM (COLD AND CONTRAST) ON DOMS PAIN TOLERANCE

2021 ◽  
Vol 9 (2) ◽  
pp. 118
Author(s):  
Dewi Sartika
Keyword(s):  
Water Temperature ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Pain Tolerance ◽  
Group I ◽  
The Mean ◽  
Group Ii ◽  
Better Than ◽  
Tolerance Improvement

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.

Influence of skeletal muscle glycogen on passive rewarming after hypothermia

1988 ◽  
Vol 65 (2) ◽  
pp. 805-810 ◽  
Author(s):  
P. D. Neufer ◽  
A. J. Young ◽  
M. N. Sawka ◽  
S. R. Muza
Keyword(s):  
Body Fat ◽  
Muscle Glycogen ◽  
Cold Water ◽  
Mild Hypothermia ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Moderate Hypothermia ◽  
Group A ◽  
Passive Rewarming ◽  
Group B

To examine the influence of muscle glycogen on the thermal responses to passive rewarming subsequent to mild hypothermia, eight subjects completed two cold-water immersions (18 degrees C), followed by 75 min of passive rewarming (24 degrees C air, resting in blanket). The experiments followed several days of different exercise-diet regimens eliciting either low (LMG; 141.0 +/- 10.5 mmol.kg.dry wt-1) or normal (NMG; 526.2 +/- 44.2 mmol.kg.dry wt-1) prewarming muscle glycogen levels. Cold-water immersion was performed for 180 min or to a rectal temperature (Tre) of 35.5 degrees C. In four subjects (group A, body fat = 20 +/- 1%), postimmersion Tre was similar to preimmersion Tre for both trials (36.73 +/- 0.18 vs. 37.26 +/- 0.18 degrees C, respectively). Passive rewarming in group A resulted in an increase in Tre of only 0.13 +/- 0.08 degrees C. Conversely, initial rewarming Tre for the other four subjects (group B, body fat = 12 +/- 1%) averaged 35.50 +/- 0.05 degrees C for both trials. Rewarming increased Tre similarly in group B during both LMG (0.76 +/- 0.25 degrees C) and NMG (0.89 +/- 0.13 degrees C). Afterdrop responses, evident only in those individuals whose body core cooled during immersion (group B), were not different between LMG and NMG. These data support the contention that Tre responses during passive rewarming are related to body insulation. Furthermore these results indicate that low muscle glycogen levels do not impair rewarming time nor alter after-drop responses during passive rewarming after mild-to-moderate hypothermia.

Human thermoregulatory responses during cold water immersion after artificially induced sunburn

1992 ◽  
Vol 262 (4) ◽  
pp. R617-R623 ◽  
Author(s):  
K. B. Pandolf ◽  
R. W. Gange ◽  
W. A. Latzka ◽  
I. H. Blank ◽  
A. J. Young ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Rectal Temperature ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
The Body ◽  
Esophageal Temperature ◽  
Mean Skin Temperature ◽  
Thermoregulatory Responses ◽  
The Mean

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)

scholarly journals Strength and Dimensional Stability of Cement-bonded Boards Manufactured from Mixture of Ceiba pentandra and Gmelina arborea Sawdust

2019 ◽  
pp. 1-10
Author(s):  
E. A. Adelusi ◽  
K. O. Olaoye ◽  
F. G. Adebawo
Keyword(s):  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Modulus Of Rupture ◽  
Gmelina Arborea ◽  
Mean Values ◽  
Mixing Ratios ◽  
Ceiba Pentandra ◽  
The Mean ◽  
Weight Proportion

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.

The Beneficial Effect of Parasympathetic Reactivation on Sympathetic Drive During Simulated Rugby Sevens

2016 ◽  
Vol 11 (4) ◽  
pp. 480-488 ◽  
Author(s):  
Jamie Douglas ◽  
Daniel J. Plews ◽  
Phil J. Handcock ◽  
Nancy J. Rehrer
Keyword(s):  
Cold Water ◽  
Water Immersion ◽  
Team Sport ◽  
Cold Water Immersion ◽  
Average Heart Rate ◽  
Performance Task ◽  
Parasympathetic Reactivation ◽  
Natural Logarithm ◽  
Repeated Sprint ◽  
The Mean

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.

scholarly journals Predictive Ability of Body Fat Percentage and Thigh Anthropometrics on Tissue Cooling during Cold Water Immersion

10.4085/40-20 ◽  
2020 ◽  
Author(s):  
Nicholas Rech ◽  
Eadric Bressel ◽  
Talin Louder
Keyword(s):  
Body Fat ◽  
Cold Water ◽  
Water Immersion ◽  
Rectus Femoris ◽  
Cold Water Immersion ◽  
Body Fat Percentage ◽  
Fat Percentage ◽  
Post Exercise ◽  
Anterior Thigh ◽  
Skin Cooling

Abstract Context: Cold water immersion (CWI) is a common aid in exercise recovery. CWI effectiveness depends on the magnitude of muscle and core cooling. Individual cooling responses to CWI are variable and likely influenced by CWI dose and individual physiological characteristics. Objective: Evaluate body fat percentage and thigh anthropometrics as predictors of intramuscular and skin cooling responses to CWI. Design: Interrupted time-series. Setting: Sports medicine research center. Participants: Sixteen young adults (8 male, 8 female, age=24.3±1.84 years, height=176.4±12.7 cm, mass=86.6±29.4 kg). Intervention: Body fat percentage was measured using a three site skinfold. Thigh length, thigh circumference, anterior thigh adipose thickness, anterior thigh muscle thickness, and thigh volume were estimated using manual and ultrasound methods. Using sterile techniques, thermocouple probes were approximated in the belly of the rectus femoris (2 cm deep to sub-adipose tissue) and on the anterior mid-thigh surface. Participants cycled on an ergometer for 30 minutes at a target heart rate between 130 and 150 beats per minute. Post-exercise, participants were placed in CWI (immersion depth: iliac crest; 10°C) until intramuscular temperature was 7°C below pre-exercise baseline temperature, with a maximum immersion duration of 30 minutes. Main Outcome Measure(s): Intramuscular rectus femoris and thigh skin temperatures measured post exercise, after 10 and 15 minutes of CWI, and post-CWI. Results: Body fat percentage significantly predicted rectus femoris cooling magnitude and rate after 10 minutes of CWI, 15 minutes of CWI, and post-CWI (p &lt;0.001; R2 = 0.58–0.64). Thigh anthropometrics significantly predicted thigh skin cooling rate post-CWI (p = 0.049; R2 = 0.46). Conclusions: A simple three site skinfold assessment may improve the efficacious prescription of CWI through estimation of the dose required for minimal muscle tissue cooling.

Patient Involvement in Treatment Decision Making Can Help or Hinder Placebo Analgesia

2014 ◽  
Vol 222 (3) ◽  
pp. 165-170 ◽  
Author(s):  
Andrew L. Geers ◽  
Jason P. Rose ◽  
Stephanie L. Fowler ◽  
Jill A. Brown
Keyword(s):  
Patient Involvement ◽  
Cold Water ◽  
Prior Experience ◽  
Water Immersion ◽  
Treatment Decision ◽  
Cold Water Immersion ◽  
Not Given ◽  
Placebo Analgesia ◽  
Treatment Decision Making ◽  
Immersion Experience

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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