Effect of Beverage Flavor on Body Hydration in Hong Kong Chinese Children Exercising in a Hot Environment

2014 ◽  
Vol 26 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Stephen Heung-Sang Wong ◽  
Feng-Hua Sun
Keyword(s):  
Intermittent Exercise ◽  
Latin Square ◽  
Rest Period ◽  
Chinese Children ◽  
Total Fluid Intake ◽  
Hot Environment ◽  
Humid Environment ◽  
Flavored Water ◽  
Ad Libitum ◽  
Body Fluid Balance

The purpose of the current study was to examine the effect of flavor on voluntary drinking and thermoregulatory responses in Chinese boys and girls exercising intermittently in a hot environment. Fourteen boys and girls (9 to 11 years old) performed four 3-hour intermittent exercise sessions (20-min walking sessions at 50% VO2peak followed by a 25-minute rest period) in a hot and humid environment (~30 °C ambient temperature and ~70% relative humidity). The participants consumed 1 of 4 beverages ad libitum in a randomized sequence by using a Latin-square principle: unflavored water (W), orange-flavored water (OF), lemon-flavored water (LF), and grape-flavored water (GF). No differences were observed in the total fluid intake (W vs. OF vs. LF vs. GF: Boys, 441 ± 114 vs. 493 ± 106 vs. 387 ± 83 vs. 568 ± 146 ml; Girls, 613 ± 131 vs. 923 ± 204 vs. 825 ± 157 vs. 790 ± 166 ml), urine and sweat output, and physiological perceptual variables among trials and between sexes. The results suggested that Chinese children can maintain body fluid balance while exercising moderately in a hot and humid environment by ad libitum drinking. The flavor of the beverages had no impact on the voluntary drinking and the state of hydration in the current study.

Effect of drink flavor and NaCL on voluntary drinking and hydration in boys exercising in the heat

1996 ◽  
Vol 80 (4) ◽  
pp. 1112-1117 ◽  
Author(s):  
B. Wilk ◽  
O. Bar-Or
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Latin Square ◽  
Hydration Status ◽  
Stomach Fullness ◽  
O2 Uptake ◽  
Flavored Water ◽  
Voluntary Dehydration ◽  
Ad Libitum ◽  
Skin Temperatures

This study was intended to assess the influence of drink flavor and composition on voluntary drinking and hydration status in children exercising intermittently at 35 +/- 1 degrees C and 45-50% relative humidity. Twelve boys (9-12 yr) performed three 3-h identical sessions (four 20-min cycling bouts at 50% maximal O2 uptake followed by 25-min rest). One of three beverages (chilled to 8-10 degrees C) was assigned to each session in a Latin-square sequence: unflavored water (W), grape-flavored water (FW), and grape-flavored water plus 6% carbohydrate and 18 mmol/l NaCl (CNa). Drinking was ad libitum. Body weight, heart rate, rectal and skin temperatures, and thirst and stomach fullness perceptions were monitored periodically. Total intake was 610, 882, and 1,157 g in W, FW, and CNa, respectively (CNa-W and CNa-FW; P < 0.05). Hypohydration was observed with W (-0.65% body wt) and FW (-0.32% body wt), but drinking CNa resulted in slight overhydration (+0.47% body wt, CNa-W, CNa-FW; P < 0.05). Other physiological and all perceptual variables were insignificantly different among trails. In conclusion, while flavoring of water reduces children's voluntary dehydration, further addition of 6% carbohydrates and 18 mmol/l NaCl prevents it altogether.

Postexercise rehydration in man: the effects of carbohydrate content and osmolality of drinks ingested ad libitum

2009 ◽  
Vol 34 (4) ◽  
pp. 785-793 ◽  
Author(s):  
Gethin H. Evans ◽  
Susan M. Shirreffs ◽  
Ronald J. Maughan
Keyword(s):  
Fluid Balance ◽  
Fluid Intake ◽  
Intermittent Exercise ◽  
Recovery Period ◽  
Electrolyte Solutions ◽  
Carbohydrate Content ◽  
Whole Body ◽  
Total Fluid Intake ◽  
Before And After ◽  
Ad Libitum

The effectiveness of different carbohydrate solutions in restoring fluid balance in situations of voluntary fluid intake has not been examined previously. The effect of the carbohydrate content of drinks ingested after exercise was examined in 6 males and 3 females previously dehydrated by 1.99 ± 0.07% of body mass via intermittent exercise in the heat. Beginning 30 min after the cessation of exercise, subjects drank ad libitum for a period of 120 min. Drinks contained 31 mmol·L–1 Na+ as NaCl and either 0%, 2%, or 10% glucose with mean ± SD osmolalities of 74 ± 1, 188 ± 3, and 654 ± 4 mosm·kg–1, respectively. Blood and urine samples were collected before and after exercise, midway through rehydration, and throughout a 5 h recovery period. Total fluid intake was not different among trials (0%: 2258 ± 519 mL; 2%: 2539 ± 436 mL; 10%: 2173 ± 252 mL; p = 0.173). Urine output was also not different among trials (p = 0.160). No differences among trials were observed in net fluid balance or in the fraction of the ingested drink retained. In conclusion, in situations of voluntary fluid intake, hypertonic carbohydrate-electrolyte solutions are as effective as hypotonic carbohydrate-electrolyte solutions at restoring whole-body fluid balance.

Drink composition, voluntary drinking, and fluid balance in exercising, trained, heat-acclimatized boys

1999 ◽  
Vol 86 (1) ◽  
pp. 78-84 ◽  
Author(s):  
Anita M. Rivera-Brown ◽  
Randall Gutiérrez ◽  
Juan Carlos Gutiérrez ◽  
Walter R. Frontera ◽  
Oded Bar-Or
Keyword(s):  
Fluid Balance ◽  
Aerobic Power ◽  
Maximal Aerobic Power ◽  
Sweat Loss ◽  
Wet Bulb Globe Temperature ◽  
Flavored Water ◽  
Voluntary Dehydration ◽  
Ad Libitum ◽  
Globe Temperature ◽  
Body Fluid Balance

This study examined the effects of beverage composition on the voluntary drinking pattern, body fluid balance, and thermoregulation of heat-acclimatized trained boys exercising intermittently in outdoor conditions (wet bulb globe temperature 30.4 ± 1.0°C). Twelve boys (age 13.4 ± 0.4 yr) performed two 3-h sessions, each consisting of four 20-min cycling bouts at 60% maximal aerobic power alternating with 25-min rest. One of two beverages was assigned: unflavored water (W) or flavored water plus 6% carbohydrate and 18 mmol/l Na (CNa). Drinking was ad libitum. Total intake was higher ( P < 0.05) during CNa (1,943 ± 190 g) compared with W (1,470 ± 143 g). Euhydration was maintained with CNa (+0.18% body wt), but a mild dehydration resulted with W (−0.94% body wt; P < 0.05). Sweat loss, much higher than previously published for children of similar age, was similar between conditions (CNa = 1,644.7 ± 117.5; W = 1,750.2 ± 152.7 g). The increase in rectal temperature (CNa = 0.86 ± 0.3; W = 0.76 ± 0.1°C), heart rate, and all perceptual variables did not differ between conditions. In conclusion, a flavored carbohydrate-electrolyte drink prevents voluntary dehydration in trained heat-acclimatized boys exercising in a tropical climate despite their large sweat losses. Because hydration changes were minor, the thermoregulatory strain observed was similar between conditions.

scholarly journals Replacing grass silage with pea-barley intercrop silage in the feeding of the dairy cow

2008 ◽  
Vol 15 (3) ◽  
pp. 235 ◽  
Author(s):  
P. PURSIAINEN ◽  
M. TUORI
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
Protein Concentration ◽  
Milk Protein ◽  
Latin Square ◽  
Crude Protein Content ◽  
Grass Silage ◽  
Ad Libitum ◽  
Ad Libitum Intake ◽  
Barley Silage

The effect of replacing wilted grass silage (GS) with pea-barley intercrop silage (PBS) on feed intake, diet digestibility and milk production was studied with 8 multiparous Ayrshire-cows in a replicated 4 × 4 Latin square experiment. Proportion of PBS was 0 (PBS0), 33 (PBS33), 67 (PBS67) or 100 (PBS100) % of silage dry matter (DM). The DM content was 559 and 255 g kg-1 for GS and PBS. Crude protein content was 131 and 170 g kg-1 DM, respectively. Pea-barley silage was more extensively fermented than GS with total fermentation acid content of 120 vs. 12 g kg-1 DM. Silage was fed for ad libitum intake and supplemented with on the average 13 kg concentrate per day. Silage DM intake was 9.2 (PBS0), 9.7 (PBS33), 9.0 (PBS67) and 7.1 (PBS100) kg per day (Pquadr. < 0.05). The energy corrected milk yield [30.3 (PBS0), 29.8 (PBS33), 30.3 (PBS67), 31.3 (PBS100) kg per day] was not significantly affected by the treatment. Milk protein concentration decreased linearly (P < 0.05) in response to feeding PBS. It is concluded that PBS can replace up to two thirds of wilted, moderate quality GS in the feeding of dairy cows because in this experiment pure pea-barley silage reduced silage intake.

scholarly journals Post-Exercise Whole Body Cryotherapy (−140 °C) Increases Energy Intake in Athletes

Nutrients ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 893
Author(s):  
Chihiro Kojima ◽  
Nobukazu Kasai ◽  
Chika Kondo ◽  
Kumiko Ebi ◽  
Kazushige Goto
Keyword(s):  
Energy Intake ◽  
Intermittent Exercise ◽  
Rest Period ◽  
Whole Body ◽  
Strenuous Exercise ◽  
Acylated Ghrelin ◽  
Meal Test ◽  
Male Athletes ◽  
Post Exercise ◽  
Whole Body Cryotherapy

PURPOSE: The purpose of the present study was to investigate the effect of whole-body cryotherapy (WBC) treatment after exercise on appetite regulation and energy intake. METHODS: Twelve male athletes participated in two trials on different days. In both trials, participants performed high-intensity intermittent exercise. After 10 min following the completion of the exercise, they were exposed to a 3-min WBC treatment (−140 °C, WBC trial) or underwent a rest period (CON trial). Blood samples were collected to assess plasma acylated ghrelin, serum leptin, and other metabolic hormone concentrations. Respiratory gas parameters, skin temperature, and ratings of subjective variables were also measured after exercise. At 30 min post-exercise, energy and macronutrient intake were evaluated during an ad libitum buffet meal test. RESULTS: Although appetite-regulating hormones (acylated ghrelin and leptin) significantly changed with exercise (p = 0.047 for acylated ghrelin and p < 0.001 for leptin), no significant differences were observed between the trials. Energy intake during the buffet meal test was significantly higher in the WBC trial (1371 ± 481 kcal) than the CON trial (1106 ± 452 kcal, p = 0.007). CONCLUSION: Cold exposure using WBC following strenuous exercise increased energy intake in male athletes.

Effect of offering three amounts of maize stover to dairy cows on intake and selection

1997 ◽  
Vol 1997 ◽  
pp. 85-85
Author(s):  
J. N. Methu ◽  
E. Owen ◽  
A. Abate ◽  
M. Scarr ◽  
J. Tanner
Keyword(s):  
Dairy Cows ◽  
Crude Protein ◽  
Feeding Strategy ◽  
Latin Square ◽  
Live Weight ◽  
Leaf Sheath ◽  
Barley Straw ◽  
Maize Stover ◽  
Ad Libitum ◽  
Friesian Cows

Several studies with barley straw (e.g. Wahed et al, 1990) and sorghum stover (e.g. Osafo, 1993) have shown improvements in intake with increasing ‘ad libitum’ amounts offered. Furthermore, these studies have demonstrated that sheep and goats offered barley straw or sorghum stover in long, unprocessed form, increase intake by selecting for leaf and leaf sheath, and against stem. This phenomenon offers a simple feeding strategy to use selective feeding behaviour to improve intake and hence production. The aim of the present experiment was to study the effect of offering increasing amounts of long maize stover on intake and selection by dairy cows.Six, early- to mid-lactation Ayrshire and Friesian cows (live weight, M, 430 kg) were used in a double 3x3 Latin square design with 24-day (d) feeding periods. Cows were offered long (unchopped) maize stover at low, medium or high ‘ad libitum’ rates, i.e. 31, 59 or 87 g dry matter (DM)/kg M.d. Cows also received 3.2 kg DM/d of cotton seed cake (339 g/kg DM crude protein) in two meals at milking (0700 h and 1800 h). Stover was offered in one meal daily, at 0700 h, after collecting refusals from the previous day. Amounts of stover offered and refused were weighed daily. Samples of offered stover (0.5 kg) and refused stover (0.5 kg) were analysed for DM daily. All refused stover and 4.0 kg samples of offered stover were botanically fractionated, daily, into stem (S), leaf (L), sheath (Sh) and husk (H). Milk yield was recorded daily and cows weighed at the start and end of each period.

scholarly journals Altering the temporal distribution of energy intake with isoenergetically dense foods given as snacks does not affect total daily energy intake in normal-weight men

2000 ◽  
Vol 83 (1) ◽  
pp. 7-14 ◽  
Author(s):  
A. M. Johnstone ◽  
E. Shannon ◽  
S. Whybrow ◽  
C. A. Reid ◽  
R. J. Stubbs
Keyword(s):  
Food Intake ◽  
Energy Density ◽  
Energy Intake ◽  
Real Life ◽  
Latin Square ◽  
Temporal Distribution ◽  
Normal Weight ◽  
Daily Energy ◽  
Fixed Composition ◽  
Ad Libitum

The objectives of the present study were to examine the effects of (1) ingesting mandatory snacks v. no snacks and (2) the composition of isoenergetically-dense snacks high in protein, fat or carbohydrate, on food intake and energy intake (EI) in eight men with ad libitum access to a diet of fixed composition. Subjects were each studied four times in a 9 d protocol per treatment. On days 1–2, subjects were given a medium-fat maintenance diet estimated at 1·6 × resting metabolic rate (RMR). On days 3–9, subjects consumed three mandatory isoenergetic, isoenergetically dense (380 kJ/100 g) snacks at fixed time intervals (11.30, 15.30 and 19.30 hours). Total snack intake comprised 30 % of the subjects' estimated daily energy requirements. The treatments were high protein (HP), high carbohydrate (HC), high fat (HF) and no snack (NS). The order was randomized across subjects in a counterbalanced, Latin-square design. During the remainder of the day, subjects had ad libitum (meal size and frequency) access to a covertly manipulated medium-fat diet of fixed composition (fat: carbohydrate: protein, 40:47:13 by energy), energy density 550 kJ/100 g. All foods eaten were investigator-weighed before ingestion and left-overs were weighed after ingestion. Subjective hunger and satiety feelings were tracked hourly during waking hours using visual analogue scales. Ad libitum EI amounted to 13·9 MJ/d on the NS treatment compared with 11·7, 11·7 and 12·2 MJ/d on the HP, HC and HF diets respectively (F(3,21) 5·35; P = 0·007, sed 0·66). Total EI values were not significantly different at 14·6, 14·5, 15·0 and 14·2 MJ/d respectively. Snack composition did not differentially affect total daily food intake or EI. Average daily hunger was unaffected by the composition of the snacks. Only at 12.00 hours did subjects feel significantly more hungry during the NS condition, relative to the other dietary treatments (F(3,18) 4·42; P = 0·017). Body weight was unaffected by dietary treatment. In conclusion, snacking per se led to compensatory adjustments in feeding behaviour in lean men. Snack composition (with energy density controlled) did not affect the amount eaten of a diet of fixed composition. Results may differ in real life where subjects can alter both composition and amount of food they eat and energy density is not controlled.

Intragastric glucose but not fructose conditions robust flavor preferences in rats

1993 ◽  
Vol 265 (2) ◽  
pp. R320-R325 ◽  
Author(s):  
A. Sclafani ◽  
C. Cardieri ◽  
K. Tucker ◽  
D. Blusk ◽  
K. Ackroff
Keyword(s):  
Conditional Stimulus ◽  
Flavor Preference ◽  
Prior Work ◽  
Significant Preference ◽  
Choice Tests ◽  
Flavored Water ◽  
Subsequent Choice ◽  
Food Conditioning ◽  
Ad Libitum ◽  
Reinforcing Effects

Prior work indicates that glucose and fructose differ in their postingestive reinforcing effects. The present study investigated this phenomenon by training rats to associate the intake of flavored water with intragastric (IG) infusions of 16% sugar solutions. In experiment 1, rats had one flavor [conditional stimulus (CS)] paired with IG sugar infusions (CS+; e.g., cherry) and another flavor paired with IG water (CS-; e.g., grape) 23 h/day; Chow was available ad libitum. In subsequent choice tests, rats infused with glucose displayed a strong preference (89%) for the CS+ flavor, whereas rats infused with fructose showed only a small and nonreliable CS+ flavor preference (62%). When next trained to associate one flavor (e.g., orange) with IG glucose and another flavor (e.g., strawberry) with IG fructose, rats in both groups developed a significant preference (81%) for the glucose-paired flavor. In experiment 2, food-deprived rats were trained 2 h/day to associate a CS+ flavor with IG sugar and a CS- flavor with IG water infusions. The glucose-reinforced rats displayed a near-total preference (95%) for the CS+ flavor, whereas fructose-reinforced rats showed a much smaller CS+ preference (67%). The preference findings indicate that the postingestive consequences of glucose are much more reinforcing than those of fructose. It appears that food conditioning is mediated by chemospecific actions of nutrients rather than their general satiating or energy repleting effects.

Changes in Passive Tension of the Hamstring Muscles During a Simulated Soccer Match

2016 ◽  
Vol 11 (5) ◽  
pp. 594-601 ◽  
Author(s):  
Paul W.M. Marshall ◽  
Ric Lovell ◽  
Jason C. Siegler
Keyword(s):  
Range Of Motion ◽  
Intermittent Exercise ◽  
Muscle Tension ◽  
Sport Activity ◽  
Angular Position ◽  
Rest Period ◽  
Passive Tension ◽  
Warm Up ◽  
Soccer Match ◽  
Passive Muscle

Purpose:Passive muscle tension is increased after damaging eccentric exercise. Hamstring-strain injury is associated with damaging eccentric muscle actions, but no research has examined changes in hamstring passive muscle tension throughout a simulated sport activity. The authors measured hamstring passive tension throughout a 90-min simulated soccer match (SAFT90), including the warm-up period and every 15 min throughout the 90-min simulation.Methods:Passive hamstring tension of 15 amateur male soccer players was measured using the instrumented straight-leg-raise test. Absolute torque (Nm) and slope (Nm/°) of the recorded torque-angular position curve were used for data analysis, in addition to total leg range of motion (ROM). Players performed a 15-min prematch warm-up, then performed the SAFT90 including a 15-min halftime rest period.Results:Reductions in passive stiffness of 20–50° of passive hip flexion of 22.1−29.2% (P < .05) were observed after the warm-up period. During the SAFT90, passive tension increased in the latter 20% of the range of motion of 10.1−10.9% (P < .05) concomitant to a 4.5% increase in total hamstring ROM (P = .0009).Conclusions:The findings of this study imply that hamstring passive tension is reduced after an active warm-up that includes dynamic stretching but does not increase in a pattern suggestive of eccentric induced muscle damage during soccer-specific intermittent exercise. Hamstring ROM and passive tension increases are best explained by improved stretch tolerance.

scholarly journals Drinking to Thirst Versus Drinking Ad Libitum During Road Cycling

2014 ◽  
Vol 49 (5) ◽  
pp. 624-631 ◽  
Author(s):  
Lawrence E. Armstrong ◽  
Evan C. Johnson ◽  
Laura J. Kunces ◽  
Matthew S. Ganio ◽  
Daniel A. Judelson ◽  
...  
Keyword(s):  
Body Mass ◽  
Perceived Exertion ◽  
Fluid Intake ◽  
Thermal Sensation ◽  
Drinking Behavior ◽  
Total Fluid Intake ◽  
Finish Line ◽  
Road Cycling ◽  
Significant Difference ◽  
Ad Libitum

Context: The sensation of thirst is different from the complex behavior of drinking ad libitum. Rehydration recommendations to athletes differ, depending on the source, yet no previous researchers have systematically compared drinking to thirst (DTT) versus ad libitum drinking behavior (DAL). Objective: To compare 2 groups of trained cyclists (DTT and DAL) who had similar physical characteristics and training programs (P &gt; .05). The DTT group (n = 12, age = 47 ± 7 years) drank only when thirsty, whereas the DAL group (n = 12, age = 44 ± 7 years) consumed fluid ad libitum (ie, whenever and in whatever volume desired). Design: Cohort study. Setting: Road cycling (164 km) in the heat (36.1°C ± 6.5°C). Patients or Other Participants: Ultraendurance cyclists (4 women, 20 men). Intervention(s): We recorded measurements 1 day before the event, on event day before the start, at 3 roadside aid stations, at the finish line, and 1 day after the event. Main Outcome Measure(s): Body mass, urinary hydration indices, and food and fluids consumed. Results: No between-groups differences were seen on event day for total exercise time (DTT = 6.69 ± 0.89 hours, DAL = 6.66 ± 0.77 hours), urinary indices (specific gravity, color), body mass change (DTT = −2.22% ± 1.73%, DAL = −2.29% ± 1.62%), fluid intake (DTT = 5.63 ± 2.59 L/6.7 h, DAL = 6.04 ± 2.37 L/6.7 h), dietary energy intake, macronutrient intake, ratings of thirst (DTT start = 2 ± 1, DTT finish = 6 ± 1, DAL start = 2 ± 1, DAL finish = 6 ± 1), pain, perceived exertion, or thermal sensation. Total fluid intake on recovery day +1 was the primary significant difference (DAL = 5.13 ± 1.87 L/24 h, DTT = 3.13 ± 1.53 L/24 h, t18 = 2.59, P = .02). Conclusions: Observations on event day indicated that drinking to thirst and drinking ad libitum resulted in similar physiologic and perceptual outcomes. This suggests that specific instructions to “drink to thirst” were unnecessary. Indeed, if athletes drink ad libitum, they can focus on training and competition rather than being distracted by ongoing evaluation of thirst sensations.

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