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.

scholarly journals Low pre‐exercise muscle glycogen availability offsets the effect of post‐exercise cold water immersion in augmenting PGC‐1α gene expression

2019 ◽  
Vol 7 (11) ◽  
pp. e14082 ◽  
Author(s):  
Robert Allan ◽  
Adam P. Sharples ◽  
Matthew Cocks ◽  
Barry Drust ◽  
John Dutton ◽  
...  
Keyword(s):  
Gene Expression ◽  
Muscle Glycogen ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Post Exercise ◽  
Exercise Muscle

Postexercise Cold-Water Immersion Does Not Attenuate Muscle Glycogen Resynthesis

2013 ◽  
Vol 45 (6) ◽  
pp. 1174-1181 ◽  
Author(s):  
WARREN GREGSON ◽  
ROBERT ALLAN ◽  
SUSAN HOLDEN ◽  
PADRAIC PHIBBS ◽  
DOMINIC DORAN ◽  
...  
Keyword(s):  
Muscle Glycogen ◽  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Glycogen Resynthesis

Muscle glycogen utilization during shivering thermogenesis in humans

1988 ◽  
Vol 65 (5) ◽  
pp. 2046-2050 ◽  
Author(s):  
L. Martineau ◽  
I. Jacobs
Keyword(s):  
Skeletal Muscle ◽  
Muscle Glycogen ◽  
Cold Water ◽  
Vastus Lateralis ◽  
Water Immersion ◽  
Venous Blood ◽  
Cold Water Immersion ◽  
Vastus Lateralis Muscle ◽  
Glucose Levels ◽  
Shivering Thermogenesis

The purpose of the present study was to clarify the importance of skeletal muscle glycogen as a fuel for shivering thermogenesis in humans during cold-water immersion. Fourteen seminude subjects were immersed to the shoulders in 18 degrees C water for 90 min or until rectal temperature (Tre) decreased to 35.5 degrees C. Biopsies from the vastus lateralis muscle and venous blood samples were obtained before and immediately after the immersion. Metabolic rate increased during the immersion to 3.5 +/- 0.3 (SE) times resting values, whereas Tre decreased by 0.9 degrees C to approximately 35.8 degrees C at the end of the immersion. Intramuscular glycogen concentration in the vastus lateralis decreased from 410 +/- 15 to 332 +/- 18 mmol glucose/kg dry muscle, with each subject showing a decrease (P less than 0.001). Plasma volume decreased (P less than 0.001) markedly during the immersion (-24 +/- 1%). After correcting for this decrease, blood lactate and plasma glycerol levels increased by 60 (P less than 0.05) and 38% (P less than 0.01), respectively, whereas plasma glucose levels were reduced by 20% after the immersion (P less than 0.001). The mean expiratory exchange ratio showed a biphasic pattern, increasing initially during the first 30 min of the immersion from 0.80 +/- 0.06 to 0.85 +/- 0.05 (P less than 0.01) and decreasing thereafter toward basal values. The results demonstrate clearly that intramuscular glycogen reserves are used as a metabolic substrate to fuel intensive thermogenic shivering activity of human skeletal muscle.

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 < .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 < .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 < .002) were different. Strong correlations were found between cooling rate and body mass (r = −0.76, P < .001), total BSA (r = −0.74, P < .001), BSA/mass (r = 0.73, P < .001), LBM/mass (r = 0.72, P < .002), and LBM (r = −0.72, P < .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 (>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.

Effects of Pre- and Post-Exercise Cold-Water Immersion Therapy on Passive Muscle Stiffness

2019 ◽  
Vol 34 (02) ◽  
pp. 72-78 ◽  
Author(s):  
Moritz Hüttel ◽  
Tobias Golditz ◽  
Isabel Mayer ◽  
Rafael Heiss ◽  
Christoph Lutter ◽  
...  
Keyword(s):  
Cold Water ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Muscle Stiffness ◽  
Control Group ◽  
Group Exercise ◽  
Post Exercise ◽  
Group A ◽  
Set Up

Abstract Background Cold-water immersion (CWI) has become a popular preventive, regenerative and performance-enhancing intervention in various sports. However, its effects on soft tissue, including changes of intramuscular stiffness, are poorly understood. The purpose of this study was to investigate the effect of CWI on muscle stiffness. Patients/Material and Methods Thirty healthy participants were included and divided into the three following groups (n = 10): 1) post-ESU group: exercise and CWI (post-exercise set-up); 2) control group: exercise without CWI (control condition); 3) pre-ESU group: CWI alone (pre-exercise set-up). Acoustic radiation force impulse (ARFI) elastography was conducted to assess tissue stiffness (shear wave velocity, SWV). Values obtained at resting conditions (baseline, t0) were compared to values post-exercise (t1, for post-ESU group and control group), post-CWI (t2, for post-ESU group and pre-ESU group; rest for control group) and to 60-min follow-up time (t3, for all groups). Data were assessed in superficial and deep muscle tissue (rectus femoris muscle, RF; vastus intermedius muscle, VI). Results For the post-ESU group (CWI post-exercise), there was no significant difference between the time points of measurements: exercise (t1: RF: 1.63 m/s; VI: 1.54 m/s), CWI (t2: RF: 1.63 m/s; VI: 1.53 m/s) and at 60-min follow-up (t3: RF: 1.72 m/s; VI: 1.61 m/s). In the control group, a significant decrease of SWV was found between baseline conditions at t0 and post-exercise (t1) at VI (VI: 1.37 m/s; p = 0.004; RF: 1.59 m/s; p = 0.084). For t2 and t3, no further significant changes were detected. Regarding the pre-exercise set-up (pre-ESU group), a significant decrease in SWV from baseline to t2 in VI (1.60 m/s to 1.49 m/s; VI: p = 0.027) was found. Conclusion This study shows varying influences of CWI on muscle stiffness. Overall, we did not detect any significant effects of CWI on muscle stiffness post-exercise. Muscle stiffness-related effects of CWI differ in the context of a pre- or post-exercise condition and have to be considered in the implementation of CWI to ensure its potential preventive and regenerative benefits.

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.

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.

Effects of muscle glycogen and plasma FFA availability on human metabolic responses in cold water

1991 ◽  
Vol 71 (4) ◽  
pp. 1331-1339 ◽  
Author(s):  
L. Martineau ◽  
I. Jacobs
Keyword(s):  
Nicotinic Acid ◽  
Muscle Glycogen ◽  
Cold Water ◽  
Vastus Lateralis ◽  
Water Immersion ◽  
Plasma Free Fatty Acid ◽  
Cold Water Immersion ◽  
Glucose Levels ◽  
Exercise Regimen ◽  
Muscle Groups

The purpose of this study was to investigate whether simultaneous alterations in the availability of plasma free fatty acids and muscle glycogen would impair the maintenance of thermal balance during cold water immersion in humans. Eight seminude subjects were immersed on two occasions in 18 degrees C water for 90 min or until rectal temperature (Tre) decreased to 35.5 degrees C. Each immersion followed 2.5 days of a specific dietary and exercise regimen designed to elicit low (LOW) or high glycogen levels (HIGH) in large skeletal muscle groups. Nicotinic acid (1.6 mg/kg) was administered for 2 h before and during immersion to inhibit white adipose tissue lipolysis. Biopsies from the vastus lateralis showed that the glycogen concentration before the immersion was significantly lower in LOW than in HIGH (223 +/- 19 vs. 473 +/- 24 mmol glucose units/kg dry muscle). However, the mean rates of glycogen utilization were not significantly different between trials (LOW 0.62 +/- 0.14 vs. HIGH 0.88 +/- 0.15 mmol glucose units.kg-1.min-1). Nicotinic acid dramatically reduced plasma free fatty acid levels in both trials, averaging 127 +/- 21 mumol/l immediately before the immersion. Cold water immersion did not significantly alter those levels. Plasma glucose levels were significantly reduced after cold water immersion to a similar extent in both trials (18 +/- 4%). Mean respiratory exchange ratio at rest and during immersion was greater in HIGH than LOW, whereas there were no intertrial differences in O2 uptake. The calculated average metabolic heat production during immersion tended to be lower (P = 0.054) in LOW than in HIGH (15.3 +/- 1.9 vs. 17.5 +/- 1.9 kJ/min).(ABSTRACT TRUNCATED AT 250 WORDS)

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 <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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