Athletes and nonathletes frequently consume too little water or fluids, affecting exercise performance as well as overall health. This book comprehensively reviews the aspects relating to body fluid ...balance, rehydration, and physical exercise. It provides background on body water balance and turnover, topics related to electrolyte balance, and sweating as the basis for thermoregulatory and fluid homeostasis during exercise. In addition, chapters cover body water balance evaluation and regulation; cardiovascular and metabolic responses to fluid imbalance; effects of dehydration on aerobic power, muscle strength, and cognitive function; fluid intake timing; and optimal beverage selection.
To verify the thermoregulatory and perceptual responses of obese and lean girls, either fit or unfit, exercising in the heat at a similar rate of metabolic heat production per unit body mass.
A total ...of 34 pubescent girls were allocated in four groups: 12 obese fit, 9 obese unfit, 5 lean fit, and 8 lean unfit. The obese groups (13.2±1.4 years, 40.5%±5.8% fat by DXA) differed in their aerobic fitness (V˙O2peak 76.0±8.1 vs. 56.6±5.8mL.kgmusclemass−1.min−1), as well as the lean groups (13.1±1.6 years, 24.0%±4.8% fat) (V˙O2peak 74.5±2.9 vs. 56.2±5.0mL.kgmuscle mass−1min−1). Girls cycled two bouts of 25min with a 10min rest in between, at ∼5.4W.kg−1 in the heat (36°C and 40% relative humidity) and they were kept euhydrated. Rectal and skin temperatures and heart rate were measured every 5min. Perceptual responses were evaluated throughout the exercise.
Initial rectal temperature was higher in the obese subjects compared to the lean subjects (37.5±0.3 and 37.2±0.3°C). No difference was observed among the girls whom were obese (eight fit or unfit) and lean (also fit or unfit) throughout the exercise in rectal temperature (37.6±0.2, 37.5±0.3, 37.5±0.3, 37.4±0.3°C, respectively), skin temperature (34.8±0.8, 35.1±1.0, 34.4±0.9, 35.2±0.9°C), and heart rate (128±18; 118±12, 130±16, 119±16beatsmin−1). No differences were observed in perceptual responses among groups.
Regardless of the adiposity or aerobic fitness, pubescent girls had similar thermoregulatory and perceptual responses while cycling in the heat at similar metabolic heat production.
Verificar as respostas termorregulatórias e perceptivas de meninas obesas e magras, com alta e baixa aptidão aeróbica, exercitando-se no calor com produção metabólica de calor similar por massa corporal.
Um total de 34 meninas púberes foram alocadas em quatro grupos: 12 obesas com alta aptidão aeróbica, 9 obesas com baixa aptidão aeróbica, 5 magras com alta aptidão aeróbica e 8 magras com baixa aptidão aeróbica. Os grupos obesos (13,2±1,4 anos, 40,5%±5,8% de gordura por DXA) diferiram em sua aptidão aeróbica (V˙O2peak 76,0±8,1 vs. 56,6±5,8 mL.kg de massa muscular-1.min-1), bem como os grupos magros (13,1±1,6 anos, 24,0%±4,8% de gordura) (V˙O2peak 74,5±2,9 vs. 56,2±5,0 mL.kg de massa muscular-1min-1). As meninas pedalaram duas sessões de 25 minutos com descanso de 10 minutos entre as sessões, a ∼5,4 W.kg-1 no calor (36°C e 40% de umidade relativa) e foram mantidas hidratadas. As temperaturas retal e cutânea e a frequência cardíaca foram medidas a cada 5 minutos. As respostas perceptivas foram avaliadas durante o exercício.
A temperatura retal inicial foi maior nas meninas obesas em comparação com as magras (37,5±0,3 e 37,2±0,3°C). Não houve diferença entre as meninas obesas (com alta aptidão aeróbica ou não) e magras (também com alta aptidão aeróbica ou não) durante todo o exercício em relação à temperatura retal (37,6±0,2; 37,5±0,3; 37,5±0,3; 37,4±0,3°C; respectivamente), temperatura da pele (34,8±0,8; 35,1±1,0; 34,4±0,9; 35,2±0,9°C), e frequência cardíaca (128±18; 118±12, 130±16, 119±16 batimentos.min-1). Não foram observadas diferenças nas respostas perceptivas entre os grupos.
Independentemente da adiposidade ou do condicionamento aeróbico, as meninas púberes tiveram respostas termorregulatórias e perceptivas semelhantes, enquanto pedalavam no calor com uma produção metabólica de calor similar.
Purpose
Child–adult thermoregulatory comparisons may be biased by differences in metabolic heat production (
H
˙
p
). We compared thermoregulatory responses of boys and men exercising at two ...intensities prescribed to elicit either a fixed
H
˙
p
per unit body mass (BM) or a fixed absolute
H
˙
p
.
Methods
Ten boys (10–12 years) and 10 men (19–25 years) performed 4 × 20-min cycling at a fixed
H
˙
p
per BM (W kg
−1
) at 35 °C and 35 % relative humidity (MEN
REL
). Men also cycled (MEN
ABS
) at the same absolute
H
˙
p
(in W) as the boys.
Results
H
˙
p
was lower in boys compared with MEN
REL
, but similar to MEN
ABS
(mean ± SD, 233.6 ± 38.4, 396.5 ± 72.3, 233.6 ± 34.1 W, respectively,
P
< 0.001). Conversely,
H
˙
p
per unit BM was similar between boys and MEN
REL
, and lower in MEN
ABS
(5.7 ± 1.0, 5.6 ± 0.8 and 3.3 ± 0.3 W kg
−1
, respectively;
P
< 0.001). The change in rectal temperature was similar between boys and MEN
REL
(0.6 ± 0.2 vs. 0.7 ± 0.2 °C,
P
= 0.92) but was lower in MEN
ABS
(0.3 ± 0.2 °C,
P
= 0.004). Sweat volume was lower in boys compared to MEN
ABS
(500 ± 173 vs. 710 ± 150 mL;
P
= 0.041), despite the same evaporative heat balance requirement (
E
req
) (199.1 ± 34.2 vs. 201.0 ± 32.7 W,
P
= 0.87).
Conclusion
Boys and men demonstrated similar thermoregulatory responses to 80 min of exercise in the heat performed at a fixed
H
˙
p
per unit BM. Sweat volume was lower in boys compared to men, despite similarities in absolute
H
˙
p
and
E
req
.
The increasing demand for seafood is responsible for many environmental impacts, especially caused by aquaculture. Shrimp accounts for a substantial part of seafood production and therefore also for ...negative effects associated with it. This work aimed to develop a mushroom-based shrimp analogue with a texture similar to shrimp using the fruiting bodies of pink oyster mushroom (
Pleurotus djamor
) and lion’s mane (
Hericium erinaceus
). Three flushes of pink oyster mushrooms and a first flush of lion’s mane mushroom were analysed regarding their nutritional composition and whether they are suitable shrimp alternatives. The two mushrooms are rich in proteins (∼32% and ∼26% w/w for the first flush of pink oyster and lion’s mane, respectively). The protein content of pink oyster mushroom decreased and the dietary fibre content increased across the different flushes. The antioxidants in the mushrooms were extracted using different methods, whereby aqueous extracts mostly excelled in terms of antioxidant activity. Hydrolysis confirmed the presence of conjugated
p
-coumaric acid in both mushrooms and possibly conjugated caffeic acid in pink oyster. Texture analysis results of the prototypes were close to the values of fried shrimp. However, although the sensory qualities of the final prototypes were perceived as similar to shrimp, further improvements in the recipe are necessary to make the prototypes indistinguishable from shrimp.
Image 1
•
Lion’s mane and pink oyster mushrooms possess good nutritional quality.
•
Conjugated phenolic acids were detected in the mushroom extracts.
•
Texture analyses of prototypes closely mimicked shrimp texture.
Industrial Relevance: Consumption of seafood like shrimps has massive impacts on the environment as it causes overfishing and bycatch, or water pollution due to aquacultures. To shift consumption to more sustainable choices, comparable alternatives to seafood and shrimps are needed. Shrimps contain high amounts of protein whilst they are low in calories and fat. Mushrooms are suggested as possible substitutions due to their high-quality nutritional profiles. Mushroom-based shrimp analogues with a texture similar to shrimp were then developed. Currently, there is a gap between the consumer demand for more choices of sustainable vegetarian/vegan seafood and plant-based seafood products being sold. The “Mushrimps” will fill this gap and open up a new market of plant-based seafood alternatives that are healthy, nutritious, and sustainable, and which take advantage of locally-grown ingredients.
Objective To compare thermoregulatory and perceptual responses between lean and obese girls during and after exercise under heat (HC) and thermoneutral (TC) conditions. Study design In a randomized ...order, 27 girls (14 lean 16.6 ± 6.7% fat and 9.1 ± 1.3 years and 13 obese 41.3 ± 6.7% fat and 9.4 ± 1.1 years) cycled 30 minutes at ∼55% peak oxygen uptake in 2 sessions, which only differed in the thermal conditions (35°C and 40% relative humidity vs 24°C and 50% relative humidity). Results Initial rectal temperature (Tre ) was higher in obese versus lean during HC (37.5 ± 0.3°C vs 37.3 ± 0.3°C, P = .03) and TC (37.6 ± 0.3°C vs 37.3 ± 0.2°C; P = .03) sessions. During cycling, Tre remained higher in the obese, but the rate of increase was greater in the lean. This change occurred mainly in the HC, when final Tre of the lean surpassed that of the obese (37.8 ± 0.2 vs 38.0 ± 0.2°C, P = .04). Sweat volume (in mL. m−2 ) was similar between lean and obese in the HC (167 ± 119 and 120 ± 145) and TC (200 ± 196 vs 72 ± 20). Heart rate, rate of perceived exertion, and thermal sensation were similar between groups, independent of the thermal condition. Cycling in HC produced decreased thermal comfort ( P = .009) and increased irritation ( P = .02) within the lean girls. Conclusion Thermoregulatory and perceptual responses of prepubescent obese girls during 30 minutes of cycling at a similar relative intensity do not seem to be impaired when comparing with a lean group either in TC or HC.
To verify the thermoregulatory and perceptual responses of obese and lean girls, either fit or unfit, exercising in the heat at a similar rate of metabolic heat production per unit body mass.
A total ...of 34 pubescent girls were allocated in four groups: 12 obese fit, 9 obese unfit, 5 lean fit, and 8 lean unfit. The obese groups (13.2±1.4 years, 40.5%±5.8% fat by DXA) differed in their aerobic fitness (V˙O2peak 76.0±8.1 vs. 56.6±5.8mL.kgmusclemass‐1.min−1), as well as the lean groups (13.1±1.6 years, 24.0%±4.8% fat) (V˙O2peak 74.5±2.9 vs. 56.2±5.0mL.kgmuscle mass−1min−1). Girls cycled two bouts of 25min with a 10min rest in between, at ∼5.4W.kg−1 in the heat (36°C and 40% relative humidity) and they were kept euhydrated. Rectal and skin temperatures and heart rate were measured every 5min. Perceptual responses were evaluated throughout the exercise.
Initial rectal temperature was higher in the obese subjects compared to the lean subjects (37.5±0.3 and 37.2±0.3°C). No difference was observed among the girls whom were obese (eight fit or unfit) and lean (also fit or unfit) throughout the exercise in rectal temperature (37.6±0.2, 37.5±0.3, 37.5±0.3, 37.4±0.3°C, respectively), skin temperature (34.8±0.8, 35.1±1.0, 34.4±0.9, 35.2±0.9°C), and heart rate (128±18; 118±12, 130±16, 119±16beatsmin−1). No differences were observed in perceptual responses among groups.
Regardless of the adiposity or aerobic fitness, pubescent girls had similar thermoregulatory and perceptual responses while cycling in the heat at similar metabolic heat production.
Verificar as respostas termorregulatórias e perceptivas de meninas obesas e magras, com alta e baixa aptidão aeróbica, exercitando‐se no calor com produção metabólica de calor similar por massa corporal.
Um total de 34 meninas púberes foram alocadas em quatro grupos: 12 obesas com alta aptidão aeróbica, 9 obesas com baixa aptidão aeróbica, 5 magras com alta aptidão aeróbica e 8 magras com baixa aptidão aeróbica. Os grupos obesos (13,2 ± 1,4 anos, 40,5% ± 5,8% de gordura por DXA) diferiram em sua aptidão aeróbica (V˙O2peak 76,0 ± 8,1 vs. 56,6 ± 5,8 mL.kg de massa muscular−1.min−1), bem como os grupos magros (13,1 ± 1,6 anos, 24,0% ± 4,8% de gordura) (V˙O2peak 74,5 ± 2,9 vs. 56,2 ± 5,0 mL.kg de massa muscular−1min−1). As meninas pedalaram duas sessões de 25 minutos com descanso de 10 minutos entre as sessões, a ∼5,4 W.kg−1 no calor (36∘C e 40% de umidade relativa) e foram mantidas hidratadas. As temperaturas retal e cutânea e a frequência cardíaca foram medidas a cada 5 minutos. As respostas perceptivas foram avaliadas durante o exercício.
A temperatura retal inicial foi maior nas meninas obesas em comparação com as magras (37,5±0,3 e 37,2±0,3°C). Não houve diferença entre as meninas obesas (com alta aptidão aeróbica ou não) e magras (também com alta aptidão aeróbica ou não) durante todo o exercício em relação à temperatura retal (37,6±0,2; 37,5±0,3; 37,5±0,3; 37,4±0,3°C; respectivamente), temperatura da pele (34,8±0,8; 35,1±1,0; 34,4±0,9; 35,2±0,9°C), e frequência cardíaca (128±18; 118±12, 130±16, 119±16 batimentos.min−1). Não foram observadas diferenças nas respostas perceptivas entre os grupos.
Independentemente da adiposidade ou do condicionamento aeróbico, as meninas púberes tiveram respostas termorregulatórias e perceptivas semelhantes, enquanto pedalavam no calor com uma produção metabólica de calor similar.
Because swimmers train in an aquatic environment, they probably do not need to sweat as much as runners who train on land and, therefore, should not develop the same magnitude of sweating ...adaptations.
To compare sweat rate and electrolyte concentration in swimmers, runners and nonathletes.
Ten swimmers (22.9 ± 3.1 years old), 10 runners (25 ± 2.9 y) and 10 nonathletes (26.5 ± 2.2 y) cycled in the heat (32 degrees Celsius and 40% relative humidity) for 30 min at similar intensity relative to their maximal cycle test. Sweat volume was calculated from the difference of their body mass before and after cycling, since they were not allowed to drink. Sweat was collected from the scapula using absorbent patch placed on the skin that was cleaned with distilled water. After cycling, the patch was transferred to syringe and the sample was obtained when squeezing it to a tube. Concentration of sodium (Na+), chloride (Cl-) and potassium (K+) were analyzed using an ion selector analyzer.
The sweat volume, in liters, of swimmers (0.9 ± 0.3) was lower (P < .05) than that of runners (1.5 ± 0.2) and similar to that of nonathletes (0.6 ± 0.2). Na+ and Cl-, in mmol x L(-1), of swimmers (65.4 ± 5.5 and 61.2 ± 81), and nonathletes (67.3 ± 8.5 and 58.3 ± 9.6) were higher (P < .05) than those of runners (45.2 ± 7.5 and 38.9 ± 8.3). K+ was similar among groups.
The lower sweat volume and higher sweat Na+ and Cl- of swimmers, as compared with runners, indicate that training in the water does not cause the same magnitude of sweating adaptations.
DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n2p143 It’s unclear whether the combination of intense, chronic training and heat exposure during prepubescence improves thermoregulatory responses to ...exercise in artistic gymnastics athletes. The objective of this study was to compare thermoregulatory and perceptual responses between artistic gymnastics athletes and non-athlete girls while exercising both in heat and thermoneutral conditions. Seven athletes (8.7 ± 1.3 yrs) and 7 nonathletes (9.4 ± 1.5 yrs) cycled for 30 min at load (W) of ~55% VO2peak, on two separate occasions in a randomized order: heat (35˚C, 40% relative humidity) and thermoneutral conditions (24˚C, 50% relative humidity). Rectal temperature, heart rate, rate of perceived exertion, thermal sensation, thermal comfort and irritability were measured throughout the exercise. Initial rectal temperature was similar between athletes and non-athletes in both heat (37.2 ± 0.4 vs. 37.4 ± 0.2˚C, respectively) and thermoneutral conditions (37.3 ± 0.2 vs. 37.3 ± 0.3˚C). Final rectal temperature was similar between groups (38.0 ± 0.2 vs. 38.2 ± 0.2˚C in heat and 37.8 ± 0.2 vs. 37.9 ± 0.2˚C in thermoneutral conditions). Initial heart rate was lower in athletes in the heat (76 ± 7 vs. 91 ± 11 bpm, P = 0.01); however, throughout cycling, it became similar between groups. Athletes reported similar perceptual responses compared to non-athletes, with the exception of higher thermal comfort in the 10th minute of exercise in thermoneutral conditions (P = 0.003). It was concluded that athletes were similar to non-athletes with respect to thermoregulatory and perceptual responses during 30 min of cycling at similar relative intensities.
Este estudo aborda as características termorregulatórias, recursos de prevenção e de diagnóstico do déficit hidroeletrolítico e danos causados pela prática do exercício no calor em crianças. ...Exercitar-se no calor pode levar a um aumento da temperatura central, e comprometer o desempenho e a saúde das crianças. O sistema termorregulatório delas está em desenvolvimento; e a eliminação do calor, por evaporação do suor, fica prejudicada, já que as crianças apresentam menores taxa de sudorese e concentração de eletrólitos no suor do que os adultos. A avaliação do estado de hidratação pré-exercício pode ser importante para prevenir que a criança inicie o exercício desidratada. Além disso, considerando que muitas vezes elas não bebem a quantidade de líquido necessária pra evitar a desidratação durante o exercício, as crianças devem ser educadas a se hidratar antes, durante e após o exercício, especialmente no calor.
Este estudio aborda las características termorreguladoras y proporciona recursos de prevención y diagnóstico de déficit hidroelectrolítico y de los daños causados por el ejercicio en el calor en niños. La práctica de ejercicio en el calor puede llevar a un aumento de la temperatura central, comprometiendo los resultados y la salud de los niños. El sistema termorregulador de ellos está en desarrollo, y la eliminación del calor, por evaporación del sudor, resulta comprometida, dado que los niños presentan menor tasa de sudoresis y concentración de electrólitos en el sudor que los adultos. La evaluación del estado de hidratación antes del ejercicio puede ser importante para prevenir que el niño comience el ejercicio deshidratado y, como muchas veces no beben la cantidad de líquido necesaria para evitar la deshidratación durante el ejercicio, se les debe enseñar a hidratarse antes, durante y después del ejercicio en el calor.
This study addresses thermoregulatory characteristics and provides resources for prevention and diagnosis of hydroelectrolyte deficits and damage resulting from exercise in the heat by children. Exercise in the heat can lead to an increase in core temperature, thus impairing children's performance and health. The thermoregulatory system is still developing in childhood, and the elimination of the heat produced during physical exercise by sweat evaporation is impaired in children, as they have lower sweat rate and electrolyte concentration in the heat than adults. Pre-exercise assessment of hydration status is important to avoid children starting to exercise in a dehydrated state. As they often do not drink enough to avoid dehydration while exercising in the heat, they should be educated to drink before, during and after exercise, especially in the heat.
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