scholarly journals Effect of caffeine ingestion on fluid balance during exercise in the heat and during recovery

2014 ◽  
Vol 26 (2) ◽  
pp. 43
Author(s):  
Yang Zhang ◽  
S J Carter ◽  
R E Schumacker ◽  
Y H Neggers ◽  
M D Curtner-Smith, ◽  
...  
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Fluid Balance ◽  
Recovery Period ◽  
The Body ◽  
Body Mass Loss ◽  
Caffeine Ingestion ◽  
Hot Environment ◽  
Urine Production ◽  
Randomised Controlled

Background. The effect of ingestion of a common stimulant, caffeine, on fluid balance during exercise and recovery is not fully known. Objectives. To determine the effect of caffeine on fluid balance during exercise in the heat and during a 3-hour recovery period thereafter. Methods. In a randomised, controlled design, caffeine-naive participants (N=8) pedalled on a bike to achieve 2.5% baseline body mass loss in a hot environment in four separate conditions: with (C+) or without (C–) caffeine ingestion (6 mg/kg of body mass) prior to exercise, followed by (W+) or without (W–) 100% fluid replenishment (water) of the body mass loss during a 3-hour recovery period (yielding C+W+, C+W–, C–W+ and C–W–, respectively). Results. Mean (standard deviation) urine production was not different (p>0.05) regardless of rehydration status: 230 (162) mL (C+W–) v. 168 (77) mL (C–W–); and 713 (201) mL (C+W+) v. 634 (185) mL (C–W+). For the 3-hour recovery, caffeine ingestion caused higher hypohydration during rehydration conditions (p=0.02), but practically the mean difference in the loss of body mass was only 0.2 kg. Conclusion. In practical terms, there was no evidence that caffeine ingestion in moderation would impair fluid balance during prolonged exercise in the heat or during 3 hours of recovery.

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.

scholarly journals Accuracy of Urine Color to Detect Equal to or Greater Than 2% Body Mass Loss in Men

2015 ◽  
Vol 50 (12) ◽  
pp. 1306-1309 ◽  
Author(s):  
Amy L. McKenzie ◽  
Colleen X. Muñoz ◽  
Lawrence E. Armstrong
Keyword(s):  
Mass Loss ◽  
Likelihood Ratio ◽  
Body Mass ◽  
Positive Likelihood Ratio ◽  
Negative Likelihood Ratio ◽  
Hydration Status ◽  
Body Mass Loss ◽  
Diagnostic Efficacy ◽  
Hot Environment ◽  
Urine Color

Context  Clinicians and athletes can benefit from field-expedient measurement tools, such as urine color, to assess hydration state; however, the diagnostic efficacy of this tool has not been established. Objective  To determine the diagnostic accuracy of urine color assessment to distinguish a hypohydrated state (≥2% body mass loss [BML]) from a euhydrated state (<2% BML) after exercise in a hot environment. Design  Controlled laboratory study. Setting  Environmental chamber in a laboratory. Patients or Other Participants  Twenty-two healthy men (age = 22 ± 3 years, height = 180.4 ± 8.7 cm, mass = 77.9 ± 12.8 kg, body fat = 10.6% ± 4.6%). Intervention(s)  Participants cycled at 68% ± 6% of their maximal heart rates in a hot environment (36°C ± 1°C) for 5 hours or until 5% BML was achieved. At the point of each 1% BML, we assessed urine color. Main Outcome Measure(s)  Diagnostic efficacy of urine color was assessed using receiver operating characteristic curve analysis, sensitivity, specificity, and likelihood ratios. Results  Urine color was useful as a diagnostic tool to identify hypohydration after exercise in the heat (area under the curve = 0.951, standard error = 0.022; P < .001). A urine color of 5 or greater identified BML ≥2% with 88.9% sensitivity and 84.8% specificity (positive likelihood ratio = 5.87, negative likelihood ratio = 0.13). Conclusions  Under the conditions of acute dehydration due to exercise in a hot environment, urine color assessment can be a valid, practical, inexpensive tool for assessing hydration status. Researchers should examine the utility of urine color to identify a hypohydrated state under different BML conditions.

scholarly journals Symposium on ‘Performance, exercise and health’ Hydration, fluids and performance

2008 ◽  
Vol 68 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Susan M. Shirreffs
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Endurance Exercise ◽  
Exercise Performance ◽  
Team Sports ◽  
Endurance Performance ◽  
The Body ◽  
Dietary Recommendations ◽  
Mental Performance ◽  
Body Mass Loss

Sweat evaporation can be a key thermoregulatory mechanism and it causes a loss of water from all compartments of the body. Hypohydration can also develop with restricted fluid intake or with intake of diuretics. Hypohydration can affect physical and/or mental performance and/or have implications for dietary recommendations. A variety of different types and modes of exercise performance can be influenced by hydration state. Reviews of the published literature are currently most conclusive for endurance exercise. Dehydration equivalent to 2% body mass loss during exercise in a hot environment (31–32°C) impairs endurance performance, but when the exercise is performed in a temperate environment (20–21°C) a 2% body mass loss appears to have a lesser and inconsequential effect. In cold environments a body mass loss >2% may be tolerable for endurance exercise. There is a less conclusive picture as to the effects of hypohydration on other types of physical performance, including strength and power activities, team sports and the skills component of many sports, and for mental performance. A number of physiological mechanisms are responsible for the effects observed. Fluid consumption can be used to attenuate the development of a water deficit or to correct it. The composition and temperature of a drink and the volume and rate of its consumption can all influence the physiological responses to ingestion and can impact on exercise performance.

scholarly journals Effect of Fourteen Days of Acclimatization on Athletic Performance in Tropical Climate

2002 ◽  
Vol 27 (6) ◽  
pp. 551-562 ◽  
Author(s):  
Bruno Voltaire ◽  
Olivier Galy ◽  
Olivier Coste ◽  
Sébastien Racinais ◽  
André Callis ◽  
...  
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Sweat Rate ◽  
Tropical Climate ◽  
The Body ◽  
Tympanic Temperature ◽  
Body Mass Loss ◽  
Tropical Conditions ◽  
The Mean ◽  
And Performance

In order to study the acclimatization process over 14 days of exposure to tropical climate, 9 triathletes performed 4 outdoor indirect continuous multistage tests in both thermoneutral and tropical conditions. The thermoneutral test (TN, 14 °C, 45% rh) was performed before traveling to the tropical area (Martinique, FWI). The tropical tests were performed 2, 8, and 14 days after arrival (32.9 °C, 78% rh). During each trial, we measured tympanic temperature, sweat rate, body mass loss, heart rate (HR), and performance. The results showed that 1) the mean tympanic temperature was greater in T2 (P < .001), T8 (P < .01) and T14 (P < .01) than in TN and significantly lower in T14 than in T2 (P < .05); 2) the mean sweat rate was significantly greater (P < .001) in T2, T8 and T14 than in TN and significantly greater (P < .05) in T8 and T14 than in T2; 3) the body mass loss after trials was significantly greater (P < .001) in T2, T8 and T14 than in TN and significantly greater (P < .05) in T8 and T14 than in T2; 4) the mean HR and HR at rest were significantly higher (P < .005) in T2 than in TN, T8, T14 and the mean HR was significantly lower (P < .05) in T14 than in the other trials; and 5) the performance time was significantly lower in T2 (P < 0.02), T8 (P < 0.03) and T14 (P < 0.05) than in TN. We concluded that 14 days of exposure to tropical climate led to changes in physiological parameters but were still insufficient to ensure complete acclimatization in well-trained athletes. The hot/wet climate induced impairment of physiological responses and performance that were still evident on the 14th day. Keywords: triathletes, aerobic performance, jet lag, dehydration, hyperthermia

scholarly journals Sauna-induced body mass loss in physically inactive young women and men

2016 ◽  
Vol 8 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Robert Podstawski ◽  
Tomasz Boraczyński ◽  
Michał Boraczyński ◽  
Dariusz Choszcz ◽  
Stefan Mańkowski ◽  
...  
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Young Women ◽  
Body Height ◽  
The Body ◽  
Regression Equations ◽  
Full Time ◽  
Body Mass Loss ◽  
Increased Risk ◽  
Physically Inactive

SummaryStudy aim: The aim of this study was to evaluate the relationship between basic somatic features (body mass and height) and body mass loss in physically inactive young women and men exposed to thermal stress in a dry sauna.Materials and methods: The research was conducted in 2015 on 685 first-year full-time students (333 women, 352 men), aged 19–20 years old. Nude body mass was measured after the students dried off before and after using the sauna.Results: An analysis of regression equations indicated that an increase in the body mass of women and men leads to a significant increase in sauna-induced body mass loss. On the other hand, body mass loss decreased with an increase in height in women and men, but to a smaller extent. From among the tested somatic features, body height and body mass, body mass had a decisive influence on body mass loss. Body height had a minimal and statistically non-significant impact on body mass loss.Conclusions: The results of this study indicate that heavier individuals have an increased risk of dehydration and hyperthermia. Therefore, they should pay close attention to replenishing fluids lost in the sauna. The determination of body mass loss values after a visit to a dry sauna has practical significance because it supports the estimation of the fluid volume required for the maintenance of correct water balance.

Protein and lipid utilization during long-term fasting in emperor penguins

1988 ◽  
Vol 254 (1) ◽  
pp. R61-R68 ◽  
Author(s):  
J. P. Robin ◽  
M. Frain ◽  
C. Sardet ◽  
R. Groscolas ◽  
Y. Le Maho
Keyword(s):  
Uric Acid ◽  
Mass Loss ◽  
Body Mass ◽  
Phase Ii ◽  
Plasma Concentrations ◽  
The Body ◽  
Phase Iii ◽  
Body Mass Loss ◽  
Emperor Penguins

The body mass of male emperor penguins is approximately 38 kg at the beginning of the 4-mo winter fast connected with breeding, and it is an estimated approximately 18 kg in leanest birds at time of spontaneous refeeding. For a 38- to 18-kg range, we investigated the changes in the rate of body mass loss, body composition, and plasma concentrations of uric acid and urea. After the first few days (phase I) a steady state (phase II) was reached in the proportions of the energy derived from proteins and lipids with proteins accounting for a constant 4%, and the remaining 96% being from lipids. The same proportions were maintained until body mass had decreased to 24 kg. Below this value the proportion of energy derived from proteins increased progressively (phase III), being 14 times higher at 18 kg than during phase II. Rate of body mass loss and plasma uric acid and urea concentrations closely reflected the changes in protein utilization: being at a low and steady value throughout phase II and increasing during phase III. Emperor penguins also fast during the spring, but for periods of only 2-3 wk. We found a 2.5 times higher value for rate of body mass loss, uric acid, and urea during spring phase II, suggesting lower effectiveness in protein sparing at that time. It may be attributed to the lower initial lipid reserves of spring birds. Would these findings be generalized to the wide variety of birds and mammals that spontaneously fast under natural conditions?(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals BODY MASS LOSS IN DRY SAUNA AND HEART RATE RESPONSE TO HEAT STRESS

2018 ◽  
Vol 24 (4) ◽  
pp. 258-262
Author(s):  
Tomasz Boraczyński ◽  
Michał Boraczyński ◽  
Robert Podstawski ◽  
Krzysztof Borysławski ◽  
Krzysztof Jankowski
Keyword(s):  
Heart Rate ◽  
Mass Loss ◽  
Body Mass ◽  
Healthy Adult ◽  
Heat Exposure ◽  
The Body ◽  
Adult Males ◽  
Body Mass Loss ◽  
Physiological Variables ◽  
Sauna Bathing

ABSTRACT Objectives: The aim of the study was to determine the effects of sauna-induced heat exposure on body mass loss (BML) and its relationships with basic anthropometric and physiological variables. Methods: The sample comprised 230 healthy adult males aged 21.0 ± 1.08 years (age range: 20.0–24.5 years). Body surface area (BSA) was determined and two groups of individuals with high BSA (BSAH; n = 58) and low BSA (BSAL; n = 74) were extracted. The intervention consisted of two 10-min dry sauna sessions separated by a 5-min interlude. Pre-, peri-, and post-sauna measures of nude body mass (BM) and heart rate (HR) were taken. Results: BML differed between BSA groups by 0.28 kg (74.81%). Absolute and relative BML most strongly correlated with BM and BSA (p < 0.001). Among the four considered height–weight indexes, the Quetelet I Index and Body Mass Index showed the strongest associations (p < 0.001) with BML whereas the weakest were with the Rohrer Index (p < 0.01) and Slenderness Index (p < 0.05). Compared with BML, differences in HR were relatively minor (from 9.90% to 18.07%) and a significant association was observed between BML and HR at rest (p < 0.01) and in 10th and 20th min of sauna bathing (p < 0.001). Conclusions: The magnitude of BML in healthy adult males after passive heat exposure was dependent on BM and concomitantly BSA. The physiological cost of dry sauna-induced thermal strain (as assessed by BML and HR) is greater in individuals with high BM and BSA. BM and HR monitoring is also recommended in order to minimize the risk of homeostatic imbalance and cardiovascular events and this cohort should more frequently cool the body and consume a greater volume of fluids during sauna bathing. Evidence Level II; Prospective comparative study.

23 Nutritional Intake and Weight Change in Severely Burned Patients

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S20-S21
Author(s):  
Sandrine O Fossati ◽  
Beth A Shields ◽  
Renee E Cole ◽  
Adam J Kieffer ◽  
Saul J Vega ◽  
...  
Keyword(s):  
Wound Healing ◽  
Mass Loss ◽  
Performance Improvement ◽  
Body Mass ◽  
Total Body Surface Area ◽  
Nutritional Intake ◽  
Energy Deficit ◽  
Body Mass Loss ◽  
Improvement Project ◽  
Burn Care

Abstract Introduction Nutrition is crucial for recovery from burn injuries, as severe weight (wt.) loss can lead to impaired immunity and wound healing, infections, skin graft failure, and mortality. Previous studies recommended avoiding more than 10% wt. loss, as this level resulted in increased infection rates. However, wt. loss is often not quantifiable during the critical illness phase, with severe edema masking non-fluid related body wt. changes. Energy (kcal) deficits can be used to estimate wt. loss until the edema has resolved, but previous studies in non-burn patients indicate that actual wt. loss is less than the commonly used 3500 kcal per pound of fat (7700 kcal per kg of fat). The objective of this performance improvement project was to evaluate nutritional intake and the resulting dry wt. change in severely burned patients. Methods This performance improvement project was approved by our regulatory compliance division. We performed a retrospective evaluation on patients with at least 20% total body surface area (TBSA) burns admitted for initial burn care to our intensive care unit over a 7-year period. Patients who died or who had major fascial excisions or limb amputations were excluded. Patients who did not achieve a recorded dry wt. after wound healing were not included in this analysis. Retrospective data were collected, including sex, age, burn size, kcal intake, kcal goal per the Milner equation using activity factor of 1.4, admission dry wt., dry wt. after wound healing (defined as less than 10% TBSA open wound), and days to dry wt. after wound healing. Descriptive statistics and linear regression were performed using JMP. Significance was set at p&lt; 0.05. Results The 30 included patients had the following characteristics: 90% male, 30 ± 11 years old, 45% ± 15% TBSA burn. They received 2720 ± 1092 kcal/day, meeting 68% ± 24% kcal goal, and took approximately 53 ± 30 days from injury to achieve dry wt. after wound healing. These patients had wt. loss of 8 ± 8 kg from the kcal deficit of 69,819 ± 51,704 during this time period. The kcal deficit was significantly associated with wt. change [p &lt; 0.001, R2 = 0.49, wt. change in kg = (-0.000103 x kcal deficit) – 1]. This translates to one kg of body wt. loss resulting from 9709 kcal deficit. Conclusions This performance improvement project found that an energy deficit of approximately 9700 kcal in our patients equates to 1 kg of body mass loss (4400 kcal deficit equates to 1 pound of body mass loss). These findings are similar to wt. loss studies in other patient populations and contrary to the commonly used 3500 kcal per pound of fat (7700 kcal per kg of fat).

Sign in / Sign up

Export Citation Format

Share Document