scholarly journals Effect of milk protein addition to a carbohydrate–electrolyte rehydration solution ingested after exercise in the heat

2010 ◽  
Vol 105 (3) ◽  
pp. 393-399 ◽  
Author(s):  
Lewis J. James ◽  
David Clayton ◽  
Gethin H. Evans
Keyword(s):  
Body Mass ◽  
Milk Protein ◽  
Intermittent Exercise ◽  
Fluid Retention ◽  
Whole Body ◽  
Protein Solution ◽  
Before And After ◽  
K Concentration ◽  
Exercise Induced ◽  
Carbohydrate Solution

The present study examined the effects of milk protein on rehydration after exercise in the heat, via the comparison of energy- and electrolyte content-matched carbohydrate and carbohydrate–milk protein solutions. Eight male subjects lost 1·9 (sd 0·2) % of their body mass by intermittent exercise in the heat and rehydrated with 150 % of their body mass loss with either a 65 g/l carbohydrate solution (trial C) or a 40 g/l carbohydrate, 25 g/l milk protein solution (trial CP). Urine samples were collected before and after exercise and for 4 h after rehydration. Total cumulative urine output after rehydration was greater for trial C (1212 (sd 310) ml) than for trial CP (931 (sd 254) ml) (P < 0·05), and total fluid retention over the study was greater after ingestion of drink CP (55 (sd 12) %) than that after ingestion of drink C (43 (sd 15) %) (P < 0·05). At the end of the study period, whole body net fluid balance (P < 0·05) was less negative for trial CP ( − 0·26 (sd 0·27) litres) than for trial C ( − 0·52 (sd 0·30) litres), and although net negative for both the trials, it was only significantly negative after ingestion of drink C (P < 0·05). The results of the present study suggest that when matched for energy density and fat content, as well as for Na and K concentration, and when ingested after exercise-induced dehydration, a carbohydrate–milk protein solution is better retained than a carbohydrate solution. These results suggest that gram-for-gram, milk protein is more effective at augmenting fluid retention than carbohydrate.

scholarly journals A Sodium Drink Enhances Fluid Retention During 3 Hours of Post-Exercise Recovery When Ingested With a Standard Meal

2017 ◽  
Vol 27 (4) ◽  
pp. 344-350 ◽  
Author(s):  
Gethin H. Evans ◽  
Jennifer Miller ◽  
Sophie Whiteley ◽  
Lewis J. James
Keyword(s):  
Body Mass ◽  
Intermittent Exercise ◽  
Urine Volume ◽  
Fluid Retention ◽  
Plain Water ◽  
Nacl Solution ◽  
Standard Meal ◽  
Before And After ◽  
Exercise Induced ◽  
Experimental Trials

The purpose of this study was to examine the efficacy of water and a 50 mmol/L NaCl solution on postexercise rehydration when a standard meal was consumed during rehydration. Eight healthy participants took part in two experimental trials during which they lost 1.5 ± 0.4% of initial body mass via intermittent exercise in the heat. Participants then rehydrated over a 60-min period with water or a 50 mmol/L NaCl solution in a volume equivalent to 150% of their body mass loss during exercise. In addition, a standard meal was ingested during this time which was equivalent to 30% of participants predicted daily energy expenditure. Urine samples were collected before and after exercise and for 3 hr after rehydration. Cumulative urine volume (981 ± 458 ml and 577 ± 345 mL; p = .035) was greater, while percentage fluid retained (50 ± 20% and 70 ± 21%; p = .017) was lower during the water compared with the NaCl trial respectively. A high degree of variability in results was observed with one participant producing 28% more urine and others ranging from 18–83% reduction in urine output during the NaCl trial. The results of this study suggest that after exercise induced dehydration, the ingestion of a 50 mmol/L NaCl solution leads to greater fluid retention compared with water, even when a meal is consumed postexercise. Furthermore, ingestion of plain water may be effective for maintenance of fluid balance when food is consumed in the rehydration period.

scholarly journals Effect of varying the concentrations of carbohydrate and milk protein in rehydration solutions ingested after exercise in the heat

2013 ◽  
Vol 110 (7) ◽  
pp. 1285-1291 ◽  
Author(s):  
Lewis J. James ◽  
Gethin H. Evans ◽  
Joshua Madin ◽  
Darren Scott ◽  
Michael Stepney ◽  
...  
Keyword(s):  
Fluid Balance ◽  
Milk Protein ◽  
Urine Osmolality ◽  
Whole Body ◽  
Protein Solution ◽  
Rehydration Solutions ◽  
Milk Protein Content ◽  
High Concentrations ◽  
Exercise Induced ◽  
Carbohydrate Solution

The present study investigated the relationship between the milk protein content of a rehydration solution and fluid balance after exercise-induced dehydration. On three occasions, eight healthy males were dehydrated to an identical degree of body mass loss (BML, approximately 1·8 %) by intermittent cycling in the heat, rehydrating with 150 % of their BML over 1 h with either a 60 g/l carbohydrate solution (C), a 40 g/l carbohydrate, 20 g/l milk protein solution (CP20) or a 20 g/l carbohydrate, 40 g/l milk protein solution (CP40). Urine samples were collected pre-exercise, post-exercise, post-rehydration and for a further 4 h. Subjects produced less urine after ingesting the CP20 or CP40 drink compared with the C drink (P< 0·01), and at the end of the study, more of the CP20 (59 (sd 12) %) and CP40 (64 (sd 6) %) drinks had been retained compared with the C drink (46 (sd 9) %) (P< 0·01). At the end of the study, whole-body net fluid balance was more negative for trial C ( − 470 (sd 154) ml) compared with both trials CP20 ( − 181 (sd 280) ml) and CP40 ( − 107 (sd 126) ml) (P< 0·01). At 2 and 3 h after drink ingestion, urine osmolality was greater for trials CP20 and CP40 compared with trial C (P< 0·05). The present study further demonstrates that after exercise-induced dehydration, a carbohydrate–milk protein solution is better retained than a carbohydrate solution. The results also suggest that high concentrations of milk protein are not more beneficial in terms of fluid retention than low concentrations of milk protein following exercise-induced dehydration.

Volume repletion after exercise-induced volume depletion in humans: replacement of water and sodium losses

1998 ◽  
Vol 274 (5) ◽  
pp. F868-F875 ◽  
Author(s):  
Susan M. Shirreffs ◽  
Ronald J. Maughan
Keyword(s):  
Body Mass ◽  
Fluid Balance ◽  
Intermittent Exercise ◽  
Sodium Intake ◽  
Recovery Period ◽  
Whole Body ◽  
Sodium Balance ◽  
Volume Depletion ◽  
Urine Production ◽  
Exercise Induced

Sodium and water loss during, and replacement after, exercise-induced volume depletion was investigated in six volunteers volume depleted by 1.89 ± 0.17% (SD) of body mass by intermittent exercise in a warm, humid environment. Subjects exercised in a large, open plastic bag, allowing collection of all sweat secreted during exercise. For over 60 min beginning 40 min after the end of exercise, subjects ingested drinks containing 0, 25, 50, or 100 mmol/l sodium ( trials 0, 25, 50, and 100) in a volume (ml) equivalent to 150% of the mass lost (g) by volume depletion. Body mass loss and sweat electrolyte (Na+, K+, and Cl−) loss were the same on each trial. The measured sweat sodium concentration was 49.2 ± 18.5 mmol/l, and the total loss (63.9 ± 38.7 mmol) was greater than that ingested on trials 0 and 25. Urine production over the 6-h recovery period was inversely related to the amount of sodium ingested. Subjects were in whole body negative sodium balance on trials 0 (−104 ± 48 mmol) and 25 (−65 ± 30 mmol) and essentially in balance on trial 50(−13 ± 29 mmol) but were in positive sodium balance on trial 100 (75 ± 40 mmol). Only on trial 100 were subjects in positive fluid balance at the end of the study. There was a large urinary loss of potassium over the recovery period on trial 100, despite a negligible intake during volume repletion. These results confirm the importance of replacement of sodium as well as water for volume repletion after sweat loss. The sodium intake on trial 100 was appropriate for acute fluid balance restoration, but its consequences for potassium levels must be considered to be undesirable in terms of whole body electrolyte homeostasis for anything other than the short term.

Carbohydrate exerts a mild influence on fluid retention following exercise-induced dehydration

2010 ◽  
Vol 108 (2) ◽  
pp. 245-250 ◽  
Author(s):  
Kristin L. Osterberg ◽  
Shannon E. Pallardy ◽  
Richard J. Johnson ◽  
Craig A. Horswill
Keyword(s):  
Body Mass ◽  
Urine Volume ◽  
Fluid Retention ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Excessive Sweating ◽  
Rehydration Solutions ◽  
Before And After ◽  
Postexercise Recovery ◽  
Exercise Induced

Rapid and complete rehydration, or restoration of fluid spaces, is important when acute illness or excessive sweating has compromised hydration status. Many studies have investigated the effects of graded concentrations of sodium and other electrolytes in rehydration solutions; however, no study to date has determined the effect of carbohydrate on fluid retention when electrolyte concentrations are held constant. The purpose of this study was to determine the effect of graded levels of carbohydrate on fluid retention following exercise-induced dehydration. Fifteen heat-acclimatized men exercised in the heat for 90 min with no fluid to induce 2–3% dehydration. After a 30-min equilibration period, they received, over the course of 60 min, one of five test beverages equal to 100% of the acute change in body mass. The experimental beverages consisted of a flavored placebo with no electrolytes (P), placebo with electrolytes (P + E), 3%, 6%, and 12% carbohydrate solutions with electrolytes. All beverages contained the same type and concentration of electrolytes (18 meq/l Na+, 3 meq/l K+, 11 meq/l Cl−). Subjects voided their bladders at 60, 90, 120, 180, and 240 min, and urine specific gravity and urine volume were measured. Blood samples were taken before exercise and 30, 90, 180, and 240 min following exercise and were analyzed for glucose, sodium, hemoglobin, hematocrit, renin, aldosterone, and osmolality. Body mass was measured before and after exercise and a final body mass was taken at 240 min. There were no differences in percent dehydration, sweat loss, or fluid intake between trials. Fluid retention was significantly greater for all carbohydrate beverages compared with P (66.3 ± 14.4%). P + E (71.8 ± 9.9%) was not different from water, 3% (75.4 ± 7.8%) or 6% (75.4 ± 16.4%) but was significantly less than 12% (82.4 ± 9.2%) retention of the ingested fluid. No difference was found between the carbohydrate beverages. Carbohydrate at the levels measured exerts a mild influence on fluid retention in postexercise recovery.

scholarly journals A method for evaluation of patient-specific lean body mass from limited-coverage CT images and its application in PERCIST: comparison with predictive equation

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jingjie Shang ◽  
Zhiqiang Tan ◽  
Yong Cheng ◽  
Yongjin Tang ◽  
Bin Guo ◽  
...  
Keyword(s):  
Lean Body Mass ◽  
Body Mass ◽  
Whole Body ◽  
Patient Specific ◽  
Predictive Equation ◽  
Reference Standard ◽  
Pet Ct ◽  
Before And After ◽  
Percist 1.0 ◽  
Limited Coverage

Abstract Background Standardized uptake value (SUV) normalized by lean body mass ([LBM] SUL) is recommended as metric by PERCIST 1.0. The James predictive equation (PE) is a frequently used formula for LBM estimation, but may cause substantial error for an individual. The purpose of this study was to introduce a novel and reliable method for estimating LBM by limited-coverage (LC) CT images from PET/CT examinations and test its validity, then to analyse whether SUV normalised by LC-based LBM could change the PERCIST 1.0 response classifications, based on LBM estimated by the James PE. Methods First, 199 patients who received whole-body PET/CT examinations were retrospectively retrieved. A patient-specific LBM equation was developed based on the relationship between LC fat volumes (FVLC) and whole-body fat mass (FMWB). This equation was cross-validated with an independent sample of 97 patients who also received whole-body PET/CT examinations. Its results were compared with the measurement of LBM from whole-body CT (reference standard) and the results of the James PE. Then, 241 patients with solid tumours who underwent PET/CT examinations before and after treatment were retrospectively retrieved. The treatment responses were evaluated according to the PE-based and LC-based PERCIST 1.0. Concordance between them was assessed using Cohen’s κ coefficient and Wilcoxon’s signed-ranks test. The impact of differing LBM algorithms on PERCIST 1.0 classification was evaluated. Results The FVLC were significantly correlated with the FMWB (r=0.977). Furthermore, the results of LBM measurement evaluated with LC images were much closer to the reference standard than those obtained by the James PE. The PE-based and LC-based PERCIST 1.0 classifications were discordant in 27 patients (11.2%; κ = 0.823, P=0.837). These discordant patients’ percentage changes of peak SUL (SULpeak) were all in the interval above or below 10% from the threshold (±30%), accounting for 43.5% (27/62) of total patients in this region. The degree of variability is related to changes in LBM before and after treatment. Conclusions LBM algorithm-dependent variability in PERCIST 1.0 classification is a notable issue. SUV normalised by LC-based LBM could change PERCIST 1.0 response classifications based on LBM estimated by the James PE, especially for patients with a percentage variation of SULpeak close to the threshold.

The Effect of Postexercise Milk Protein Intake on Rehydration of Children

2016 ◽  
Vol 28 (2) ◽  
pp. 286-295 ◽  
Author(s):  
Kimberly Volterman ◽  
Daniel Moore ◽  
Joyce Obeid ◽  
Elizabeth A. Offord ◽  
Brian W. Timmons
Keyword(s):  
Relative Humidity ◽  
Body Mass ◽  
Fluid Balance ◽  
Protein Intake ◽  
Milk Protein ◽  
Crossover Design ◽  
Fluid Retention ◽  
Type Method ◽  
Time Interaction ◽  
Complete Restoration

Purpose:In adults, rehydration after exercise in the heat can be enhanced with a protein-containing beverage; however, whether this applies to children remains unknown. This study examined the effect of milk protein intake on postexercise rehydration in children.Method:Fifteen children (10–12 years) performed three exercise trials in the heat (34.4 ± 0.2 °C, 47.9 ± 1.1% relative humidity). In a randomized, counterbalanced crossover design, participants consumed iso-caloric and electrolyte-matched beverages containing 0 g (CONT), 0.76 g (Lo-PRO) or 1.5 g (Hi-PRO) of milk protein/100 mL in a volume equal to 150% of their body mass (BM) loss during exercise. BM was then assessed over 4 h of recovery.Results:Fluid balance demonstrated a significant condition × time interaction (p = .012) throughout recovery; Hi-PRO was less negative than CONT at 2 hr (p = .01) and tended to be less negative at 3 h (p = .07). Compared with CONT, beverage retention was enhanced by Hi-PRO at 2 h (p < .05).Conclusion:A postexercise beverage containing milk protein can favorably affect fluid retention in children. Further research is needed to determine the optimal volume and composition of a rehydration beverage for complete restoration of fluid balance.

scholarly journals Electrolyte-free milk protein solution influences sodium and fluid retention in rats

2013 ◽  
Vol 2 ◽  
Author(s):  
Kengo Ishihara ◽  
Yoshiho Kato ◽  
Ayako Usami ◽  
Mari Yamada ◽  
Asuka Yamamura ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Body Fluid ◽  
Milk Protein ◽  
Urine Volume ◽  
Plasma Osmolality ◽  
Fluid Retention ◽  
Protein Solution ◽  
Gastric Emptying Rate ◽  
Male Wistar Rats ◽  
Total Body

AbstractMilk is an effective post-exercise rehydration drink that maintains the net positive fluid balance. However, it is unclear which components are responsible for this effect. We assessed the effect of milk protein solution (MPS) obtained by dialysis on body fluid retention. Milk, MPS, milk electrolyte solution (MES), sports drink and water were administered to male Wistar rats at a dose of 6 ml/rat after treadmill exercise. Total body fluid retention was assessed by urine volume 4 h after administration of hydrating liquids. The rate of gastric emptying was evaluated by a tracer method using 13C-labelled acetate. Plasma osmolality, Na and K levels, and urinary Na and K were measured by HPLC and osmometry, respectively. The gastric emptying rate was not delayed by MPS. During 4 h of rehydration, cumulative urine volumes differed significantly between treatment groups (P < 0·05) with 4·9, 2·2 and 3·4 ml from water-, milk- and MPS-fed rats, respectively. Thus, MPS elicited 50 % of the total body fluid retention of milk. Plasma aldosterone levels were significantly higher in MPS- and milk-fed rats compared with water-fed rats. Plasma osmolality was maintained at higher levels in MPS-fed rats than in water- and MES-fed rats (P < 0·05). Cumulative urine Na excretion was also suppressed in the milk- and MPS-fed groups compared with the MES-fed group. Our results demonstrate that MPS obtained by dialysis clearly affects net body water balance without affecting gastric emptying after exercise. This effect was attributed to retention of Na and water, and maintenance of plasma osmolality.

scholarly journals Chemically Activated Cooling Vest’s Effect on Cooling Rate Following Exercise-Induced Hyperthermia: A Randomized Counter-Balanced Crossover Study

Medicina ◽  
2020 ◽  
Vol 56 (10) ◽  
pp. 539
Author(s):  
Yuri Hosokawa ◽  
Luke N. Belval ◽  
William M. Adams ◽  
Lesley W. Vandermark ◽  
Douglas J. Casa
Keyword(s):  
Cooling Rate ◽  
Body Mass ◽  
Cold Water ◽  
Water Immersion ◽  
Heat Stroke ◽  
Cooling Capacity ◽  
Cold Water Immersion ◽  
Whole Body ◽  
Climatic Chamber ◽  
Exercise Induced

Background and objectives: Exertional heat stroke (EHS) is a potentially lethal, hyperthermic condition that warrants immediate cooling to optimize the patient outcome. The study aimed to examine if a portable cooling vest meets the established cooling criteria (0.15 °C·min−1 or greater) for EHS treatment. It was hypothesized that a cooling vest will not meet the established cooling criteria for EHS treatment. Materials and Methods: Fourteen recreationally active participants (mean ± SD; male, n = 8; age, 25 ± 4 years; body mass, 86.7 ± 10.5 kg; body fat, 16.5 ± 5.2%; body surface area, 2.06 ± 0.15 m2. female, n = 6; 22 ± 2 years; 61.3 ± 6.7 kg; 22.8 ± 4.4%; 1.66 ± 0.11 m2) exercised on a motorized treadmill in a hot climatic chamber (ambient temperature 39.8 ± 1.9 °C, relative humidity 37.4 ± 6.9%) until they reached rectal temperature (TRE) >39 °C (mean TRE, 39.59 ± 0.38 °C). Following exercise, participants were cooled using either a cooling vest (VEST) or passive rest (PASS) in the climatic chamber until TRE reached 38.25 °C. Trials were assigned using randomized, counter-balanced crossover design. Results: There was a main effect of cooling modality type on cooling rates (F[1, 24] = 10.46, p < 0.01, η2p = 0.30), with a greater cooling rate observed in VEST (0.06 ± 0.02 °C·min−1) than PASS (0.04 ± 0.01 °C·min−1) (MD = 0.02, 95% CI = [0.01, 0.03]). There were also main effects of sex (F[1, 24] = 5.97, p = 0.02, η2p = 0.20) and cooling modality type (F[1, 24] = 4.38, p = 0.047, η2p = 0.15) on cooling duration, with a faster cooling time in female (26.9 min) than male participants (42.2 min) (MD = 15.3 min, 95% CI = [2.4, 28.2]) and faster cooling duration in VEST than PASS (MD = 13.1 min, 95% CI = [0.2, 26.0]). An increased body mass was associated with a decreased cooling rate in PASS (r = −0.580, p = 0.03); however, this association was not significant in vest (r = −0.252, p = 0.39). Conclusions: Although VEST exhibited a greater cooling capacity than PASS, VEST was far below an acceptable cooling rate for EHS treatment. VEST should not replace immediate whole-body cold-water immersion when EHS is suspected.

scholarly journals Effect of Core Training on Trunk Flexor Musculature in Male Soccer Players

2017 ◽  
Vol 1 (04) ◽  
pp. E147-E154 ◽  
Author(s):  
Yohei Takai ◽  
Miyuki Nakatani ◽  
Takuya Akamine ◽  
Katsuyuki Shiokawa ◽  
Daisuke Komori ◽  
...  
Keyword(s):  
Body Mass ◽  
Training Group ◽  
Soccer Players ◽  
Whole Body ◽  
Control Group ◽  
Training Groups ◽  
Trunk Segment ◽  
Before And After ◽  
Core Training ◽  
Training Modalities

AbstractThe present study aimed to elucidate the effect of core training on trunk flexor musculature in athletes. Twenty-eight collegiate male soccer players were randomly assigned to three groups: a training group that performed core exercises with wheeled platforms (WP), a training group that performed body mass-based core exercise (BME), and a control group that did not perform core exercise training (CON). WP and BME trained twice a week for 10 weeks. The WP performed 8–14 exercises with wheeled platforms. BME conducted four core exercises to failure. Before and after the intervention, trunk segment lean body mass (LBM) was measured using a whole-body dual-energy X-ray absorptiometry scanner. Muscle thicknesses (MTs) of the rectus abdominis (RA), external oblique, internal oblique (IO), and transverse abdominis were determined with an ultrasound apparatus. No significant changes for any measured variables were found in CON. In both training groups, the trunk segment LBM was significantly increased through the intervention. While MT for IO significantly increased in the two training groups, significant increases in MT for RA were found in only WP. For collegiate soccer players, the core training programs adopted here can be effective in increasing trunk segment LBM, but the effectiveness on the trunk flexor muscularity differs between the two training modalities.

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.

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