Last Word on Viewpoint: Current evidence does not support an anticipatory regulation of exercise intensity mediated by rate of body heat storage

The purpose of the present experiment was to examine the relationship between rate of body heat storage (S˙), change in body heat content (ΔHb), extremity temperatures, and finger dexterity. S˙, ΔHb , finger skin temperature (Tfing), toe skin temperature, finger dexterity, and rectal temperature were measured during active torso heating while the subjects sat in a chair and were exposed to −25°C air. S˙ and ΔHb were measured using partitional calorimetry, rather than thermometry, which was used in the majority of previous studies. Eight men were exposed to four conditions in which the clothing covering the body or the level of torso heating was modified. After 3 h, Tfing was 34.9 ± 0.4, 31.2 ± 1.2, 18.3 ± 3.1, and 12.1 ± 0.5°C for the four conditions, whereas finger dexterity decreased by 0, 0, 26, and 39%, respectively. In contrast to some past studies, extremity comfort can be maintained, despite S˙ that is slightly negative. This study also found a direct linear relationship between ΔHb and Tfing and toe skin temperature at a negative ΔHb. In addition, ΔHb was a better indicator of the relative changes in extremity temperatures and finger dexterity over time than S˙.

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Type 2 diabetes does not exacerbate body heat storage in older adults during brief, extreme passive heat exposure

Temperature ◽

10.1080/23328940.2020.1736760 ◽

2020 ◽

Vol 7 (3) ◽

pp. 263-269 ◽

Cited By ~ 1

Author(s):

Martin P. Poirier ◽

Sean R. Notley ◽

Pierre Boulay ◽

Ronald J. Sigal ◽

Brian J. Friesen ◽

...

Keyword(s):

Type 2 Diabetes ◽

Older Adults ◽

Heat Storage ◽

Heat Exposure ◽

Body Heat

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Metabolic, thermoregulatory, and perceptual responses during exercise after lower vs. whole body precooling

Journal of Applied Physiology ◽

10.1152/japplphysiol.00720.2002 ◽

2003 ◽

Vol 94 (3) ◽

pp. 1039-1044 ◽

Cited By ~ 25

Author(s):

Andrea T. White ◽

Scott L. Davis ◽

Thad E. Wilson

Keyword(s):

Heat Storage ◽

Thermal Sensation ◽

Submaximal Exercise ◽

Whole Body ◽

Lower Body ◽

Mean Body Temperature ◽

Thermal Discomfort ◽

Healthy Men ◽

Metabolic Heat ◽

Body Heat

The purpose of this investigation was to compare the thermoregulatory, metabolic, and perceptual effects of lower body (LBI) and whole body (WBI) immersion precooling techniques during submaximal exercise. Eleven healthy men completed two 30-min cycling bouts at 60% of maximal O2uptake preceded by immersion to the suprailiac crest (LBI) or clavicle (WBI) in 20°C water. WBI produced significantly lower rectal temperature (Tre) during minutes 24–30 of immersion and lower Tre, mean skin temperature, and mean body temperature for the first 24, 14, and 16 min of exercise, respectively. Body heat storage rates differed significantly for LBI and WBI during immersion and exercise, although no net differences were observed between conditions. For WBI, metabolic heat production and heart rate were significantly higher during immersion but not during exercise. Thermal sensation was significantly lower (felt colder) and thermal discomfort was significantly higher (less comfortable) for WBI during immersion and exercise. In conclusion, WBI and LBI attenuated Tre increases during submaximal exercise and produced similar net heat storage over the protocol. LBI minimized metabolic increases and negative perceptual effects associated with WBI.

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Thermoregulation in swimmers and runners

Journal of Applied Physiology ◽

10.1152/jappl.1979.46.6.1086 ◽

1979 ◽

Vol 46 (6) ◽

pp. 1086-1092 ◽

Cited By ~ 26

Author(s):

R. G. McMurray ◽

S. M. Horvath

Keyword(s):

Oxygen Uptake ◽

Heat Storage ◽

Subcutaneous Fat ◽

Heat Content ◽

Volume Ratio ◽

Heat Acclimatization ◽

Vasomotor Control ◽

Percentage Body Fat ◽

Body Heat ◽

Control Exercise

Thermoregulatory responses of six trained swimmers and five runners to cold and heat were evaluated during 30 min of exercise (60% VO2max) while immersed to the neck in 20, 25, 30, and 35 degrees C water. Mean oxygen uptake was similar for both groups during all four trials. Changes in metabolic rate during the 8th to 28th min were significantly greater for the runners in 20 degrees C water, and swimmers in 30 and 35 degrees C water. Heart rates, Tsk, delta Tre, Tb, body heat content, and heat storage were dependent on water temperature. Runners were able to attain higher sweat rates than swimmers in 35 degrees C water. Swimmers had significantly greater tissue conductance values in the 35 degrees C exposure. Swimmers thermoregulated better in 20 degrees C water than runners, possibly due to a larger surface area-to-volume ratio, percentage body fat, subcutaneous fat, or improved vasomotor control. Exercise in the heat was better tolerated by runners. Physical training in water does not improve heat acclimatization to the extent of training in air, but does improve cold tolerance.

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