Hydration effects on thermoregulation and performance in the heat

Sawka, Michael N.; Montain, Scott J.; Latzka, W. A.

doi:10.1016/s1095-6433(01)00274-4

Cited by 229 publications

(166 citation statements)

References 69 publications

Supporting

Mentioning

153

Contrasting

Unclassified

Order By: Relevance

“…Additionally, the practice observed to lose weight and consequently the dehydration affects directly the physical capacity of athletes [28], presenting reduction in capacity of redistribution of blood flux to periphery, lower hypothalamic sensibility to sweating and lower aerobic capacity to a debt heart determined [29,30]. Additionally, in combat sports can occur a rapid increase of body mass after weighing [31], fact this that can generate a state of overhydration.…”

Section: Discussionmentioning

confidence: 99%

Weight loss in mixed martial arts athletes

Andreato¹,

Andreato²,

Santos³

et al. 2014

Journal of Combat Sports and Martial Arts

View full text Add to dashboard Cite

SummaryIntroduction. The aim of this study was to analyze the magnitude and methods of weight loss among MMA fighters and the influence of this practice in hydration and profile of mood state.Material and methods. The sample was composed by eight MMA fighters during a professional MMA competition, but only five athletes finished all procedures. To evaluate the weight loss prevalence, magnitude and methods it was applied the Rapid Weight Loss Questionnaire adapted to MMA. Saliva samples were taken in the official weigh-in and one hour before of the combats to estimate the salivary osmolality. To evaluate the profile of mood states the Brunel Mood Scale (BRUMS) was applied.Results. The results showed that all participants already had lost weight to take part in another event. The athletes reported that they always adopted as method to lose weight: to make more exercise (50 %) and reduce food intake of liquids (37.5 %). The dangers methods to health were cited by athletes in the following sequence: use of diuretics (37.5%), sauna (37.5%), training intentionally in heated training rooms (50 %) and use of diet pills (12.5%). In the competition analyzed 88% of athletes reduced their body mass (4.5 ± 4.2 kg, 5.4 ± 4.3 %) to compete. The salivary osmolality did not show significant difference between weighin (55.6 ± 30.7 mOsmol/kg H2O) and pre-match moment (40.2 ± 27.9 mOsmol/kg H2O). The profile of mood states did not change between the weigh-in (tension: 1.2 ± 1.8, depression: 0 ± 0, anger: 1.2 ± 1.6, vigour: 14.0 ± 0.7, fatigue: 2.6 ± 5.3, confusion: 0.2 ± 0.4) and the pre-match moment (tension: 2.6 ± 2.2, depression: 0 ± 0, anger: 1.4 ± 1.9, vigour: 15.6 ± 0.5, fatigue: 0.0, confusion: 2.8 ± 3.9).Conclusions. The conclusion is that there is a great prevalence of weight loss in MMA athletes in this sample. Furthermore, dangers methods to health are or were practiced to reduce the body mass to compete.

show abstract

Section: Discussionmentioning

confidence: 99%

Weight loss in mixed martial arts athletes

Andreato¹,

Andreato²,

Santos³

et al. 2014

Journal of Combat Sports and Martial Arts

View full text Add to dashboard Cite

show abstract

“…44 For example, humans and non-human primates from tropical climates have enhanced salt and water avidity. [25][26][27] Another consequence of this reliance on sweating is decreasing blood volume. 28 To maintain blood pressure and ensure organ perfusion, the vessel contraction is important.…”

Section: Discussionmentioning

confidence: 99%

“…20,21 Moreover, studies on ACE I/D polymorphisms have indicated that the Alu insertions are shown to be absent from the genomes of a number of non-human primates, consistent with the rise in human genetic polymorphisms sometime after the human/African anthropoid divergence, 22 which suggests that D allele is the ancestral allele 23,24 and its evolutionary history could be used to provide evidence for the 'thrifty genotype' hypothesis. On the other hand, accumulating evidence has suggested that genetic susceptibility to CVD as well as salt avidity and cardiovascular reactivity are ancestral and were likely magnified during the early human evolution before the out-of-Africa expansion of anatomically modern humans [25][26][27] and it is due to diverse selection pressure during the out-of-Africa expansion that occurred 30 000-100 000 years ago, among which, the most important selection pressure was climate. 28 A good candidate for a 'thrifty gene' should exhibit two important features.…”

Section: Introductionmentioning

confidence: 99%

Worldwide spatial genetic structure of angiotensin-converting enzyme gene: a new evolutionary ecological evidence for the thrifty genotype hypothesis

Sun

Jin

et al. 2011

Eur J Hum Genet

View full text Add to dashboard Cite

As JV Neel put forward the 'thrifty genotype' hypothesis, many researches tend to support this hypothesis involved in the regulation of energy balance. However, the phrase could equally well encapsulate broader traits and the forms of thrift should be multiple. In particular, genes involved in the regulation of water and sodium balance may also be excellent candidates as thrifty genes. In the present study, we selected the ancestral D allele of angiotensin-converting enzyme (ACE) gene, a key gene involved in water and sodium balance regulation, as a candidate to confirm the 'thrifty genotype' hypothesis in the framework of evolutionary ecology. On the basis of our compiled worldwide spatial genetics database of I/D frequency of ACE gene and spatial climate database, using techniques of spatial statistics, we found (1) an obvious decreasing geographic genetic cline following the route of out-of-Africa expansion from East Africa, (2) a positive association between D allele and synthetic temperature factor, (3) and a negative relationship between D allele and synthetic humidity factor that covered most regions of the world, and obvious spatial dependence between D allele and these two climate factors followed the route of out-of-Africa expansion from Africa. This suggested that D allele of ACE gene is not only plastic in response to its environmental circumstance but also presents a striking geographic distribution showing the evidence of 'signatures of selection' by climate factors. Thus, it can be identified as a thrifty allele and could provide a new evolutionary ecological evidence for the 'thrifty genotype' hypothesis.

show abstract

“…Hypohydration increases heat storage by reducing blood flow to the skin, as well as sweating rate, and subsequent hypertonicity further contributes to reduced heat loss and increased heat storage. In addition, hypovolemia and displacement of blood to the skin makes it difficult to maintain the central venous pressure, therefore, the cardiac output for simultaneous support of metabolism and thermoregulation as well (Sawka et al, 2001). This results in the maintenance of maximal sustainable heat loss with greater ease after acclimatization in September.…”

Section: Discussionmentioning

confidence: 99%

Heat Acclimatization in Hot Summer for Ten Weeks Suppress the Sensitivity of Sweating in Response to Iontophoretically-administered Acetylcholine

Lee

2008

Korean J Physiol Pharmacol

View full text Add to dashboard Cite

Hydration effects on thermoregulation and performance in the heat

Cited by 229 publications

References 69 publications

Weight loss in mixed martial arts athletes

Weight loss in mixed martial arts athletes

Worldwide spatial genetic structure of angiotensin-converting enzyme gene: a new evolutionary ecological evidence for the thrifty genotype hypothesis

Heat Acclimatization in Hot Summer for Ten Weeks Suppress the Sensitivity of Sweating in Response to Iontophoretically-administered Acetylcholine

Contact Info

Product

Resources

About