Circulatory effects of fluid loss and fluid intake during exercise

Abstract Context: Sodium replacement during prolonged exercise in the heat may be critically important to maintaining fluid and electrolyte balance and muscle contractility. Objective: To examine the effectiveness of sodium-containing sports drinks in preventing hyponatremia and muscle cramping during prolonged exercise in the heat. Design: Randomized crossover study. Patients or Other Participants: Thirteen active men. Intervention(s): Participants completed 4 trials of an exercise protocol in the heat (30°C) consisting of 3 hours of exercise (alternating 30 minutes of walking and cycling at a heart rate of 130 and 140 beats per minute, respectively); a set of standing calf raises (8 sets of 30 repetitions); and 45 minutes of steep, brisk walking (5.5 kmṡh−1 on a 12% grade). During exercise, participants consumed fluids to match body mass loss. A different drink was consumed for each trial: carbohydrate-electrolyte drink containing 36.2 mmol/L sodium (HNa), carbohydrate-electrolyte drink containing 19.9 mmol/L sodium (LNa), mineral water (W), and colored and flavored distilled water (PL). Main Outcome Measure(s): Serum sodium, plasma osmolality, plasma volume changes, and muscle cramping frequency. Results: During both HNa and LNa trials, serum sodium remained relatively constant (serum sodium concentration at the end of the protocol was 137.3 mmol/L and 136.7 mmol/L, respectively). However, a clear decrease was observed in W (134.5 ± 0.8 mmol/L) and PL (134.4 ± 0.8 mmol/L) trials compared with HNa and LNa trials (P < .05). The same trends were observed for plasma osmolality (P < .05). Albeit not significant, plasma volume was preserved during the HNa and LNa trials, but a reduction of 2.5% was observed in the W and PL trials. None of the volunteers experienced cramping. Conclusions: The data suggest that sodium intake during prolonged exercise in the heat plays a significant role in preventing sodium losses that may lead to hyponatremia when fluid intake matches sweat losses.

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Fluid volume control during short-term space flight and implications for human performance

Journal of Experimental Biology ◽

10.1242/jeb.204.18.3209 ◽

2001 ◽

Vol 204 (18) ◽

pp. 3209-3215

Author(s):

Donald E. Watenpaugh

Keyword(s):

Space Flight ◽

Fluid Intake ◽

Cell Mass ◽

Extracellular Fluid ◽

Fluid Volume ◽

Upper Body ◽

Volume Control ◽

Fluid Loss ◽

Fluid Filtration ◽

Sitting Posture

SUMMARY Space flight exerts substantial effects on fluid volume control in humans. Cardiac distension occurs during the first 1–2 days of space flight relative to supine and especially upright 1g conditions. Plasma volume contraction occurs quickly in microgravity, probably as a result of transcapillary fluid filtration into upper-body interstitial spaces. No natriuresis or diuresis has been observed in microgravity, such that diuresis cannot explain microgravity-induced hypovolemia. Reduction of fluid intake occurs irrespective of space motion sickness and leads to hypovolemia. The fourfold elevation of urinary antidiuretic hormone (ADH) levels on flight day 1 probably results from acceleration exposures and other stresses of launch. Nevertheless, it is fascinating that elevated ADH levels and reduced fluid intake occur simultaneously early in flight. Extracellular fluid volume decreases by 10–15% in microgravity, and intracellular fluid volume appears to increase. Total red blood cell mass decreases by approximately 10% within 1 week in space. Inflight Na+ and volume excretory responses to saline infusion are approximately half those seen in pre-flight supine conditions. Fluid volume acclimation to microgravity sets the central circulation to homeostatic conditions similar to those found in an upright sitting posture on Earth. Fluid loss in space contributes to reduced exercise performance upon return to 1g, although not necessarily in flight. In-flight exercise training may help prevent microgravity-induced losses of fluid and, therefore, preserve the capacity for upright exercise post-flight. Protection of orthostatic tolerance during space flight probably requires stimulation of orthostatic blood pressure control systems in addition to fluid maintenance or replacement.

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Nutrient Intake of Elite Sailors during a Solitary Long-Distance Offshore Race

International Journal of Sport Nutrition ◽

10.1123/ijsn.8.4.364 ◽

1998 ◽

Vol 8 (4) ◽

pp. 364-376 ◽

Cited By ~ 3

Author(s):

Andre-Xavier Bigard ◽

Pierre-Yves Guillemot ◽

Jean-Yves Chauve ◽

François Duforez ◽

Pierre Portero ◽

...

Keyword(s):

Body Weight ◽

Energy Intake ◽

Nutrient Intake ◽

Fluid Intake ◽

Control Period ◽

High Energy ◽

Fluid Loss ◽

Long Distance ◽

Period 2 ◽

Daily Energy

The purpose of the present study was to determine the nutritional intake of 11 skippers during the four stages of a solitary long-distance offshore race. Body weight significantly decreased during the race (−1.31 ±0.32 kg, range 3.5 to 0.1 kg, p < .01). Total daily energy intake was 18.53 ± 0.71 MJ ⋅ day-1 during the race, and it correlated negatively with the race duration of each leg. Energy intake during the race was ~ 19% greater than that determined for a subgroup of 5 sailors during a control period 2 months after the race. Nutrient intake expressed as percentage calories of total energy was estimated at 50%, 35%, and 15% for carbohydrate, fat, and protein, respectively. Voluntary fluid intake decreased with increasing race duration (p < .001). Despite high energy intakes, sailors lost body weight during the solitary offshore race. It was not possible to conclude that this change in body weight was related to fluid loss and/or a discrepancy between energy intake and energy expenditure.

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Dehydration and body fluid-regulating hormones during sweating in warm (38°C) fresh- and seawater immersion

Journal of Applied Physiology ◽

10.1152/jappl.2001.91.4.1529 ◽

2001 ◽

Vol 91 (4) ◽

pp. 1529-1534 ◽

Cited By ~ 12

Author(s):

Arvid Hope ◽

Leif Aanderud ◽

Asbjørn Aakvaag

Keyword(s):

Body Weight ◽

Body Fluid ◽

Fluid Intake ◽

Skin Surface ◽

Hot Water ◽

Fluid Loss ◽

Sweat Production ◽

Initial Decrease ◽

Effects Of Temperature ◽

Osmotic Effects

Body weight (BW) reductions of more than 4 kg have been observed during diving with the open hot water suit, a technique in which heated seawater (SW) continuously floods the skin surface. To test the hypothesis that osmotic effects may be involved in these fluid-loss processes, head-out immersion experiments in 38°C freshwater (FW) and SW for 4 h were performed. Average BW reduction was 2.5 and 1.9 kg in SW and FW head-out immersion, respectively ( P < 0.01). Atrial natriuretic peptide increased during the first 30 min of SW immersion (5.6–13.4 pmol/l, P < 0.01) followed by a reduction to 7.6 pmol/l ( P < 0.01). This paralleled an initial decrease in aldosterone (from 427 to 306 pmol/l, P < 0.05) followed by an increase to 843 pmol/l ( P < 0.01). The effects of temperature on fluid loss were studied in thermoneutral (34.5°C) and 38°C SW for 2 h. In thermoneutral SW, calculated sweat production was negligible (0.05 kg) compared with 1.2 kg in warm SW. We recommend that, if a dive is planned to last for more than 4 h, a mandatory break for fluid intake should be incorporated in the diving regulations.

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Evaluation of Fluid Loss and Customary Fluid Intake among a Selected Group of Young Swimmers: A Preliminary Field Study

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18063205 ◽

2021 ◽

Vol 18 (6) ◽

pp. 3205

Author(s):

Damian Wiśniewski ◽

Ewa Śliwicka ◽

Jakub Malik ◽

Krzysztof Durkalec-Michalski

Keyword(s):

Fluid Intake ◽

Training Session ◽

Fat Free Mass ◽

Fluid Loss ◽

Aquatic Environments ◽

Body Weights ◽

Before And After ◽

Total Body ◽

The Relationship ◽

Total Average

This study aimed to assess fluid loss (FL) and customary fluid intake (FI) during a training session, and the relationship between FL and total body water (TBW) content in a selected group of young swimmers. The study involved 17 (seven females, 10 males) individuals whose anthropometric and body composition analyses and FI during training units were carried out. The total average FI and total actual FL oscillated around 531 mL and −513 mL for the whole study group (469 mL and −284 mL for females, 574 mL and −674 mL for males). The dependent and independent sample t-tests, the Cohen’s d effect size and Pearson’s correlation coefficient were analysed. Significant differences were observed between pre-workout and post-workout body weights after training without FI in the whole group (66.5 kg vs. 66.0 kg, p < 0.001, d = 0.06), in females (61.2 kg vs. 60.9 kg, p = 0.015, d = 0.04) and males (70.3 kg vs. 69.6 kg, p < 0.001, d = 0.9). For the TBW content and fat-free mass (FFM) before and after training, significant differences were observed only in males (TBW: 43.8 L vs. 43.2 L, p = 0.002, d = 0.14; and 62.4% vs. 61.7%, p < 0.001, d = 0.36; FFM: 59.8 kg vs. 59.1 kg, p = 0.002, d = 0.12). Moreover, the relationship between the actual FL and TBW before training was observed in the whole (mL vs. %: r = −0.64, p = 0.006; mL vs. L: r = −0.84, p < 0.001) and the male group (mL vs. L: r = −0.73, p = 0.017). These results indicated FL in young swimmers during training and the relationship between FL and pre-training TBW content, which suggests that it is important to also pay special attention to effective hydration procedures before and during training in aquatic environments.

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Hydration Status in Adolescent Alpine Skiers During a Training Camp

Journal of Human Kinetics ◽

10.2478/hukin-2021-0062 ◽

2021 ◽

Vol 79 (1) ◽

pp. 55-63

Author(s):

Dirk Aerenhouts ◽

Laurent Chapelle ◽

Peter Clarys ◽

Evert Zinzen

Keyword(s):

Specific Gravity ◽

Fluid Intake ◽

Training Session ◽

Urine Specific Gravity ◽

Hydration Status ◽

Fluid Loss ◽

Individual Values ◽

Training Camp ◽

Ad Libitum ◽

Alpine Skiers

Abstract Maintaining euhydration is important for optimal health, performance and recovery, but can be challenging for alpine skiers when training in a relatively cold but dry environment. This study aimed to evaluate hydration status, fluid loss and fluid intake in adolescent alpine skiers during a training camp. Twelve athletes aged 14.3 ± 0.9 years volunteered to participate in the study. Athletes resided at an altitude of 1600 m and trained between 1614 and 2164 m. During eight consecutive days, urine specific gravity was measured before each morning training session using a refractometer. Changes in body weight representing fluid loss and ad libitum fluid intake during each morning training session were assessed using a precision scale. Mean pre-training urine specific gravity remained stable throughout the training camp. Individual values ranged between 1.010 and 1.028 g/cm3with 50 to 83% of athletes in a hypohydrated state (urine specific gravity ≥ 1.020 g/cm3). Mean training induced fluid loss remained stable throughout the training camp (range -420 to -587 g) with individual losses up to 1197 g (-3.5%). Fluid intake was significantly lower than fluid loss during each training session. To conclude, urine specific gravity values before training indicated insufficient daily fluid intake in more than half of the athletes. Furthermore, fluid intake during training in adolescent alpine skiers was suboptimal even when drinks were provided ad libitum. Coaches and athletes should be encouraged to carefully monitor hydration status and to ensure that alpine skiers drink sufficiently during and in between training sessions.

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Effect of an exercise-heat acclimation program on body fluid regulatory responses to dehydration in older men

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1999.277.4.r1041 ◽

1999 ◽

Vol 277 (4) ◽

pp. R1041-R1050 ◽

Cited By ~ 11

Author(s):

Akira Takamata ◽

Tomoyuki Ito ◽

Kazuhiro Yaegashi ◽

Hisatake Takamiya ◽

Yasuyo Maegawa ◽

...

Keyword(s):

Body Fluid ◽

Fluid Intake ◽

Heat Exposure ◽

Heat Acclimation ◽

Fluid Volume ◽

The Body ◽

Regulatory Function ◽

Fluid Loss ◽

Intermittent Light ◽

Young Subjects

We examined if an exercise-heat acclimation program improves body fluid regulatory function in older subjects, as has been reported in younger subjects. Nine older (Old; 70 ± 3 yr) and six younger (Young; 25 ± 3 yr) male subjects participated in the study. Body fluid regulatory responses to an acute thermal dehydration challenge were examined before and after the 6-day acclimation session. Acute dehydration was produced by intermittent light exercise [4 bouts of 20-min exercise at 40% peak rate of oxygen consumption (V˙o 2 peak) separated by 10 min rest] in the heat (36°C; 40% relative humidity) followed by 30 min of recovery without fluid intake at 25°C. During the 2-h rehydration period the subjects drank a carbohydrate-electrolyte solution ad libitum. In the preacclimation test, the Old lost ∼0.8 kg during dehydration and recovered 31 ± 4% of that loss during rehydration, whereas the Young lost ∼1.2 kg and recovered 56 ± 8% ( P < 0.05, Young vs. Old). During the 6-day heat acclimation period all subjects performed the same exercise-heat exposure as in the dehydration period. Exercise-heat acclimation increased plasma volume by ∼5% ( P < 0.05) in Young subjects but not in Old. The body fluid loss during dehydration in the postacclimation test was similar to that in the preacclimation in Young and Old. The fractional recovery of lost fluid volume during rehydration increased in Young (by 80 ± 9%; P < 0.05) but not in Old (by only 34 ± 5%; NS). The improved recovery from dehydration in Young was mainly due to increased fluid intake with a small increase in the fluid retention fraction. The greater involuntary dehydration (greater fluid deficit) in Old was accompanied by reduced plasma vasopressin and aldosterone concentrations, renin activity, and subjective thirst rating ( P < 0.05, Young vs. Old). Thus older people have reduced ability to facilitate body fluid regulatory function by exercise-heat acclimation, which might be involved in attenuation of the acclimation-induced increase in body fluid volume.

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Kajian Karakteristik dan Asupan Cairan pada Atlet di SMA Negeri 1 Sewon

JURNAL NUTRISIA ◽

10.29238/jnutri.v19i2.16 ◽

2017 ◽

Vol 19 (2) ◽

pp. 90-94

Author(s):

Fani Indrawati ◽

Weni Kurdanti ◽

Isti Suryani

Keyword(s):

Cardiovascular Diseases ◽

Design Research ◽

Fluid Intake ◽

Nutritional Intake ◽

Fluid Loss ◽

Direct Impact ◽

Sports Performance ◽

Interference Function ◽

Liquid Intake ◽

Energy Needs

Background: the fulfillment of energy needs and liquids athletes of nutritional intake and the fluid that adekuat is the most frequently forgotten by athletes .Needs of water per different people , are influenced by various factors like sex , age , the activity , as well as the environment .Fluid loss as many as 3 to 5% of weight resulting in interference function cardiovascular diseases that would have a direct impact on sports performance Objective: this research aims to understand the characteristics of athletes based on fluid intake on athletes in SMA Negeri 1 Sewon. Method : the kind of research is observational with the design research cross sectional.Aspects subjects covering liquid intake, age, sex, BMI and kind of sport in athletes in any kind a sport that followed.Using a technique technique sampling random stratification.Any species of sports taken as the sample.The sample of the a total of 49 respondents. Research conducted was taken from the results of interviews respondents by the SQ FFQ. Results : liquid intake in an athlete based on kinds of sports and characteristic of (the age, sex, BMI), known of 73,5 % athletes with liquid intake less. Liquid intake the average athletes was 2963,4 ml per day, with intake at least 1412,1 ml and intake maximum 4867,9 ml and standard deviations 884,15. Conclusions : Based on characteristic (age, sex, BMI) and kinds of sports, athletes with liquid intake less (73,5 %). Keywords : characteristics athletes, kind of sports, liquid intake

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Kajian Karakteristik dan Asupan Cairan pada Atlet di SMA Negeri 1 Sewon

JURNAL NUTRISIA ◽

10.29238/jnutri.v19i2.256 ◽

2017 ◽

Vol 19 (2) ◽

pp. 90

Author(s):

Fani Indrawati ◽

Weni Kurdanti ◽

Isti Suryani

Keyword(s):

Cardiovascular Diseases ◽

Design Research ◽

Fluid Intake ◽

Nutritional Intake ◽

Fluid Loss ◽

Direct Impact ◽

Sports Performance ◽

Interference Function ◽

Liquid Intake ◽

Energy Needs

Background: the fulfillment of energy needs and liquids athletes of nutritional intake and the fluid that adekuat is the most frequently forgotten by athletes .Needs of water per different people , are influenced by various factors like sex , age , the activity , as well as the environment .Fluid loss as many as 3 to 5% of weight resulting in interference function cardiovascular diseases that would have a direct impact on sports performance Objective: this research aims to understand the characteristics of athletes based on fluid intake on athletes in SMA Negeri 1 Sewon. Method : the kind of research is observational with the design research cross sectional.Aspects subjects covering liquid intake, age, sex, BMI and kind of sport in athletes in any kind a sport that followed.Using a technique technique sampling random stratification.Any species of sports taken as the sample.The sample of the a total of 49 respondents. Research conducted was taken from the results of interviews respondents by the SQ FFQ. Results : liquid intake in an athlete based on kinds of sports and characteristic of (the age, sex, BMI), known of 73,5 % athletes with liquid intake less. Liquid intake the average athletes was 2963,4 ml per day, with intake at least 1412,1 ml and intake maximum 4867,9 ml and standard deviations 884,15. Conclusions : Based on characteristic (age, sex, BMI) and kinds of sports, athletes with liquid intake less (73,5 %). characteristics athletes, kind of sports, liquid intake

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Assessment of Fluid Intake Pattern in Anambra State, Southeast Nigeria

European Journal of Medical and Health Sciences ◽

10.24018/ejmed.2020.2.3.300 ◽

2020 ◽

Vol 2 (3) ◽

Author(s):

Christian Chiibuzo Ibeh ◽

Nonyelum Nnenna Jisieike-Onuigbo ◽

Fidelia Obiageli Emelumadu ◽

Chigozie Ozoemena Ifeadike ◽

Mary Jane Umeh ◽

...

Keyword(s):

High Temperatures ◽

Fluid Intake ◽

Kidney Diseases ◽

Demographic Data ◽

Civil Servants ◽

Activity Level ◽

Fat Free Mass ◽

Temperate Climate ◽

Fluid Loss ◽

Cross Sectional

Background: Water is essential for life and accounts for about 70 percent of the human body fat-free mass. Daily loss of 2.5 L in temperate climate occurs on least minimal activity while exercises, rises in temperature, illnesses raise the fluid loss. Adequate intake of water is necessary for optimal body functions, development and health. Estimates of water intake shows wide variations depending on factors such as temperature, activity level, availability and accessibility of fluid, fluid type, packaging, and socio-cultural factors. Context and purpose of study: Residents in the tropics are exposed to high temperatures and loss of excess fluid from perspiration and would expectedly require high fluid intake for normal body function. A cross sectional study was conducted in Aanmbra State, southeast Nigeria to assess the fluid intake of subjects. Two hundred and fifty people were selected by multi-stage sampling technique. They were drawn from employees in government secretariats, banks and artisans engaged in motor mechanic worksites. Using a semi-structured questionnaire, calibrated plastic cups, weighing scale and standiometer, the socio-demographic data, the 24-hour fluid intake, weight and height of the subjects were obtained. Results: The mean age of the respondents was 36.6±11.5 years. 60.1% (146) were males while 39.9% (97) were females. There were 130 (53.5%) civil servants and 113 (46.5%) artisans. The median 24-hour fluid intake was 3.5 litres with artisans having higher intake than the civil servants. (χ2 =16.57, df=2, p<0.05). The median fluid intake for males was 3.8 litres compared with 3.1 L for females. Main findings: Less than one quarter of the subjects met the respective WHO recommendations for males and females. About half (47.9%) of the males and 39.2% of the females failed to meet the USA IOM recommendations. Conclusions: The subjects drank less fluid than people in temperate climes and below international recommendations for moderate activities and for manual labour in high temperatures. Brief summary and potential implications: Inadequate intake of fluid lead to reduced work/exercise performance, endanger health resulting in impaired cognition, kidney diseases, cardiovascular disorders and dysfunction in blood sugar regulation.

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