scholarly journals Impact of airflow on body cooling in exercise: an exploratory study

2021 ◽  
Vol 38 (5) ◽  
pp. 261-268
Author(s):  
Pedro H. Nogueira ◽  
Alisson G. da Silva ◽  
Samuel A. Oliveira ◽  
Manuel Sillero-Quintana ◽  
João C. Marins

Objective: To analyze the body heat dissipation by thermography during indoor running treadmill with different airflow conditions. Materials and method: Nine male participants (23.0±2.5 years old) underwent three 45-minute moderate-intensity running sessions (60-70% reserve heart rate) on a treadmill. At each session, a different experimental condition was applied in a crossover design: without airflow (NF), and with low (LF) and high airflow (HF) generated by a fun. Thermograms were obtained with a thermal camera before exercise, during (every 10 minutes), and after exercise. Skin temperature (Tsk) was measured on regions of interest of the upper body: pectoral, brachial biceps, and upper back. A repeated measures ANOVA was used to compare Tsk over time and between conditions, considering p<0.05 as statistically significant. Results: In pectoral and brachial biceps, LF and HF conditions provided greater reductions in Tsk at all moments when compared to the NF (p<0.05). There was a higher reduction in Tsk to the HF vs LF in biceps at 30, 40, and 45 min during exercise (p<0.05). In the upper back, Tsk remained below baseline at all moments during exercise only in the HF condition (p<0.05). In NF and LF conditions, Tsk returned to baseline at 30 min during exercise (p>0.05). Conclusion: The frontal wind flow enhances body heat dissipation during moderate-intensity running in the pectoral, brachial biceps, and upper back, with a direct relationship of flow speed and Tsk reduction during exercise.

2020 ◽  
Author(s):  
Divyajyoti Ganguly ◽  
Tiasa Adhya

Hunting strategies are key to carnivore survival (Krebs and Davies 2009;Kamil et al. 2012;Michalko and Pekar 2016). Fishing Cat’s (Prionailurus viverrinus) persistence in the ‘semi-aquatic niche’ (Kitchener et al. 2010) despite felids being terrestrial carnivores in general (>95%) (Hunter 2019) suggests the evolution of a successful hunting strategy. Its further suggest selection for hunting in wetlands. What energy conserving strategies did the Fishing Cat borrow from its family and how were these adapted to optimize energy gained from hunting fish, its primary prey? We attempt to answer this by analyzing 197 video footages collected opportunistically from a participatory science initiative conducted over 2.5 years. We found that the felid switches between stationary and active modes of searching for prey depending on the depth of water and the corresponding loss of body heat/energy. For example, diving in deeper waters requires the submergence of the upper portions of the body and loss of more body heat/energy. Our analysis shows that the cat spent much of its time (~52%) sitting and waiting for prey (fish) to come nearer and then took limited attempts to dive into deeper water (2.78%). We suggest that this is a strategy to optimize the net energy gain. In shallow waters where the cat could forage without submerging the upper body it adopted a predominantly active mode of hunting (~96%) to flush out prey. Thus, prominent hunting strategies in the small cat lineage like ‘sit-and-wait’ and ‘active foraging’ is adapted to hunt in the water. We recorded a 60% hunting success in deeper waters but did not detect a successful hunt in shallow waters due to the low sample size of data from shallow water hunting. The major caveat in our study is the post-hoc analysis of opportunistically collected data as opposed to data derived from a structured design with predefined objectives. With more sampling from various seasons and landscapes, finer details can be explored which would have conservation implications. For example, we would expect variations in ‘attempts to hunt’ during cold seasons because heat loss might be less of a challenge in the latter. Quantifying ‘attempts to hunt’ and ‘successful hunts’ across seasons could help focus management interventions to minimize negative interactions between fish cultivators and Fishing Cat. The strictly nocturnal activity of fishing cat as demonstrated in our study could be a strategy taken by the cat to avoid humans. Our approach of using participatory-science is relevant for conducting research on mammal behavior in human dominated landscapes.


Author(s):  
Radostina A. Angelova

Smart and intelligent textiles together with wearable devices for cooling the human body assure active protection of the human body in a hot environment. The purpose of this article is to present the recent inventions in the field of wearable technologies and high-performance apparel that helps the thermophysiological comfort of people in high-temperature environments. The work of the thermoregulatory system when the body heat storage is higher than the heat dissipation from the body to the environment is presented together with experimental results from thermograms during physical exercise. High-performance textiles, used in sports apparel, are analyzed in terms of their ability to cool the human body during high metabolic activity. Wearable devices for helping the thermophysiological comfort in the hot are also discussed.


2019 ◽  
Vol 44 (3) ◽  
pp. 332-335 ◽  
Author(s):  
Andrew W. D’Souza ◽  
Sean R. Notley ◽  
Erin K. Brown ◽  
Martin P. Poirier ◽  
Glen P. Kenny

Using direct calorimetry, we determined if the Hexoskin shirt (Carré Technologies Inc., Que., Canada), a wearable device for monitoring physiological strain, would compromise whole-body heat loss and exacerbate body heat storage during moderate-intensity activity in hot-dry conditions. The shirt did not impair heat dissipation and resulted in similar body heat storage when worn alone relative to a semi-nude condition (214 vs. 211 kJ) or when worn underneath a work uniform compared with a cotton undershirt (307 vs. 318 kJ).


2019 ◽  
Vol 89 (21-22) ◽  
pp. 4425-4437 ◽  
Author(s):  
Hande G Atasağun ◽  
Ayşe Okur ◽  
Agnes Psikuta ◽  
René M Rossi ◽  
Simon Annaheim

Clothing and the enclosed air layers highly affect heat dissipation from the body and thus, are crucial factors when it comes to thermal comfort. The heat and moisture transfer is affected by the variation of the size and the shape of air gaps between the garment and the human body. In addition, the fabric and garment design properties can affect the amount of heat loss from different body parts. In this study, we investigated the effect of fabric properties (different raw materials and weave types) and the garment fit on the heat loss through the garment combinations (undershirt and shirt) for the different parts of the upper body (trunk, chest, and back) using a sweating thermal manikin. The undershirt fit and the raw material of the shirts showed strong effects on the dry thermal resistance of the garment combinations. Moreover, the undershirt properties affected the evaporative heat loss from garment combinations, and the magnitude of these effects varied over different body regions. Whilst the undershirt fit had a significant impact on the evaporative heat loss of the back region, the influence of the undershirt raw material was more important in the chest region. The findings of this study provide fundamental knowledge to improve the thermal comfort of garment combinations for office wear.


1975 ◽  
Vol 38 (2) ◽  
pp. 294-299 ◽  
Author(s):  
R. Henane ◽  
J. Bittel

Heat acclimatization has been induced in 12 resting healthy men by 90-min exposure to 45C dry bulb and 24% relative humidity for 9 successive days. The most significant results ovserved were 1) increased sensitivity of sweating with marked quickening of sweat measured, 2) decreased rate of body heat storage associated with a lower rectal temperature at end of exposure, as follows: 14.07 plus or minus 1.58 Wtimeshtimeskg-1 before and 9.39 plus or minus 1.69 afterward for body heat storage; 37.55 plus or minus 0.15C before and 36.99 plus or minus 0.24C afterward for rectal temperature. In contrast, no significant changes were observed in the final sweat rates, mean skin temperatures, or the heat conductance between the body interior and skin surface. The quickness of the heat dissipation process caused by both increased sensitivity of sweating and lower internal body temperature is the major factor in achieving a thermal balance and a decreased body heat content after acclimatization.


2017 ◽  
Vol 59 (2) ◽  
pp. 014-021
Author(s):  
Saya K. Koyshibaeva ◽  
◽  
Shokhan A. Alpeyisov ◽  
Evgeniy V. Fedorov ◽  
Nina S. Badryzlova ◽  
...  

Author(s):  
Joshua S. Walden

The book’s epilogue explores the place of musical portraiture in the context of posthumous depictions of the deceased, and in relation to the so-called posthuman condition, which describes contemporary changes in the relationship of the individual with such aspects of life as technology and the body. It first examines Alfred Hitchcock’s Vertigo to view how Bernard Herrmann’s score relates to issues of portraiture and the depiction of the identity of the deceased. It then considers the work of cyborg composer-artist Neil Harbisson, who has aimed, through the use of new capabilities of hybridity between the body and technology, to convey something akin to visual likeness in his series of Sound Portraits. The epilogue shows how an examination of contemporary views of posthumous and posthuman identities helps to illuminate the ways music represents the self throughout the genre of musical portraiture.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Atsushi Tanaka ◽  
Michio Shimabukuro ◽  
Hiroki Teragawa ◽  
Yosuke Okada ◽  
Toshinari Takamura ◽  
...  

Abstract Backgrounds/Aim Sodium glucose co-transporter 2 inhibitors promote osmotic/natriuretic diuresis and reduce excess fluid volume, and this improves cardiovascular outcomes, including hospitalization for heart failure. We sought to assess the effect of empagliflozin on estimated fluid volumes in patients with type 2 diabetes and cardiovascular disease (CVD). Methods The study was a post-hoc analysis of the EMBLEM trial (UMIN000024502), an investigator-initiated, multi-center, placebo-controlled, double-blinded, randomized-controlled trial designed primarily to evaluate the effect of 24 weeks of empagliflozin treatment on vascular endothelial function in patients with type 2 diabetes and established CVD. The analysis compared serial changes between empagliflozin (10 mg once daily, n = 52) and placebo (n = 53) in estimated plasma volume (ePV), calculated by the Straus formula and estimated the extracellular volume (eEV), determined by the body surface area, measured at baseline and 4, 12, and 24 weeks after initiation of treatment. Correlations were examined between the changes from baseline to week 24 in each estimated fluid volume parameter and several clinical variables of interest, including N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration. Results In an analysis using mixed-effects models for repeated measures, relative to placebo empagliflozin reduced ePV by − 2.23% (95% CI − 5.72 to 1.25) at week 4, − 8.07% (− 12.76 to − 3.37) at week 12, and − 5.60% (− 9.87 to − 1.32) at week 24; eEV by − 70.3 mL (95% CI − 136.8 to − 3.8) at week 4, − 135.9 mL (− 209.6 to − 62.3) at week 12, and − 144.4 mL (− 226.3 to − 62.4) at week 24. The effect of empagliflozin on these parameters was mostly consistent across various patient clinical characteristics. The change in log-transformed NT-proBNP was positively correlated with change in ePV (r = 0.351, p = 0.015), but not with change in eEV. Conclusions Our data demonstrated that initiation of empagliflozin treatment substantially reduced estimated fluid volume parameters in patients with type 2 diabetes and CVD, and that this effect was maintained for 24 weeks. Given the early beneficial effect of empagliflozin on cardiovascular outcomes seen in similar patient populations, our findings provide an important insight into the key mechanisms underlying the clinical benefit of the drug. Trial registration University Medical Information Network Clinical Trial Registry, number 000024502


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
František Vejmělka ◽  
Jan Okrouhlík ◽  
Matěj Lövy ◽  
Gabriel Šaffa ◽  
Eviatar Nevo ◽  
...  

AbstractThe relatively warm and very humid environment of burrows presents a challenge for thermoregulation of its mammalian inhabitants. It was found that African mole-rats dissipate body heat mainly through their venter, and social mole-rats dissipate more body heat compared to solitary species at lower temperatures. In addition, the pattern of the ventral surface temperature was suggested to be homogeneous in social mole-rats compared to a heterogeneous pattern in solitary mole-rats. To investigate this for subterranean rodents generally, we measured the surface temperatures of seven species with different degrees of sociality, phylogeny, and climate using infrared thermography. In all species, heat dissipation occurred mainly through the venter and the feet. Whereas the feet dissipated body heat at higher ambient temperatures and conserved it at lower ambient temperatures, the ventral surface temperature was relatively high in all temperatures indicating that heat dissipation to the environment through this body region is regulated mainly by behavioural means. Solitary species dissipated less heat through their dorsum than social species, and a tendency for this pattern was observed for the venter. The pattern of heterogeneity of surface temperature through the venter was not related to sociality of the various species. Our results demonstrate a general pattern of body heat exchange through the three studied body regions in subterranean rodents. Besides, isolated individuals of social species are less able to defend themselves against low ambient temperatures, which may handicap them if staying alone for a longer period, such as during and after dispersal events.


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