Fluid and Electrolyte Balance During 24-Hour Fluid and/or Energy Restriction

2013 ◽  
Vol 23 (6) ◽  
pp. 545-553 ◽  
Author(s):  
Lewis J. James ◽  
Susan M. Shirreffs

Weight categorized athletes use a variety of techniques to induce rapid weight loss (RWL) in the days leading up to weigh in. This study examined the fluid and electrolyte balance responses to 24-hr fluid restriction (FR), energy restriction (ER) and fluid and energy restriction (F+ER) compared with a control trial (C), which are commonly used techniques to induce RWL in weight category sports. Twelve subjects (six male, six female) received adequate energy and water (C) intake, adequate energy and restricted water (~10% of C; FR) intake, restricted energy (~25% of C) and adequate water (ER) intake or restricted energy (~25% of C) and restricted (~10% of C) water intake (F+ER) in a randomized counterbalanced order. Subjects visited the laboratory at 0 hr, 12 hr, and 24 hr for blood and urine sample collection. Total body mass loss was 0.33% (C), 1.88% (FR), 1.97% (ER), and 2.44% (F+ER). Plasma volume was reduced at 24 hr during FR, ER, and F+ER, while serum osmolality was increased at 24 hr for FR and F+ER and was greater at 24 hr for FR compared with all other trials. Negative balances of sodium, potassium, and chloride developed during ER and F+ER but not during C and FR. These results demonstrate that 24 hr fluid and/or energy restriction significantly reduces body mass and plasma volume, but has a disparate effect on serum osmolality, resulting in hypertonic hypohydration during FR and isotonic hypohydration during ER. These findings might be explained by the difference in electrolyte balance between the trials.

2020 ◽  
Author(s):  
Joseph Matthews

Introduction: Mixed martial arts (MMA) athletes typically undergo energy restriction and severe dehydration to compete in a specific weight category: a process known as making weight. This can pose a health risk to athletes and has led to fatalities. Some risks can be mitigated with structured sports nutrition. Methods: This case study provides an overview of a 10-week sports nutrition intervention devised to support an elite male MMA athlete for a world lightweight title bout. Results: Over a 9-week period, body mass was reduced from 81.6 kg (baseline) to 75.4 kg (1-week pre-competition): total loss 6.2 kg (8.2%) equivalent to 0.68 kg.wk-1. In the final 5 days, body mass was reduced by a further 5.2 kg (7.4%), before regaining 5.8 kg (8.3%) and entering competition at 76 kg. There was no incidence of injury or illness throughout the training camp and the athlete reported positive feedback regarding health, wellbeing, and physical performance. Conclusions: The intervention demonstrates a pragmatic approach to making weight by allowing moderate rapid weight loss (RWL) and rapid weight gain under controlled conditions. In the absence of rule changes to prevent RWL, coaches and athletes can utilise sports nutrition strategies to minimise the risks associated with a traditional approach to making weight.


Sports ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 206 ◽  
Author(s):  
John Connor ◽  
Brendan Egan

Rapid weight loss (RWL) is frequently practiced in weight category sports, including Mixed Martial Arts (MMA). The aim of the present study was to describe self-reported methods of RWL in a sample of competitive MMA athletes comprising of both amateur and professional fighters. The previously-validated Rapid Weight Loss Questionnaire, with the addition of questions on water loading and hot salt baths, was completed anonymously online by athletes (n = 30; all male, n = 15/15 professional/amateur) from MMA clubs around Dublin, Ireland. All but one (97%) of the athletes surveyed lost weight in order to compete, with the average weight loss being 7.9% ± 3.1% of habitual body mass. The RWL score (mean ± SD) for this sample was 37.9 ± 9.6, and a tendency for higher [6.0 (95%CI; −1.1, 13.1) (p = 0.093; d = 0.64)] RWL scores for professional (40.8 ± 8.9) compared to amateur (34.8 ± 9.6) athletes was observed. Frequencies of “always” or “sometimes” were reported as 90% for water loading, 76% for hot salt baths and 55% for 24 h of fasting. Fellow fighters (41%) and coaches/mentors (38%) were “very influential” on RWL practices of these athletes, with doctors (67%), dietitians (41%), and physical trainers (37%) said to be “not influential”. RWL is highly prevalent in MMA across both amateur and professional athletes, and RWL scores are higher than other combat sports. Water loading and hot salt baths are amongst the most commonly used methods of RWL despite little research on these methods for body mass reduction or effects on performance in weight category sports.


1984 ◽  
Vol 57 (1) ◽  
pp. 123-128 ◽  
Author(s):  
S. E. Kravik ◽  
L. C. Keil ◽  
J. E. Silver ◽  
N. Wong ◽  
W. A. Spaul ◽  
...  

To investigate fluid, electrolyte, and plasma vasopressin (PVP) and renin activity (PRA) responses, six men (20–35 yr) were immersed to the neck (NI) in water at 34.5 degrees C for six h after overnight food and fluid restriction. Diuresis was 1,061 +/- 160 (SE) ml/6 h during immersion and water balance was -1,285 +/- 104 ml/6 h. Preimmersion PVP was 0.7 +/- 0.2 pg/ml and increased to 3.0 +/- 0.6 pg/ml (P less than 0.05) at 6 h. PVP was unchanged at 1.2 +/- 0.1 pg/ml in the 6-h seated nonimmersionexperiment at 25 degrees C. Plasma volume increased by 7.8 +/- 1.6% (P less than 0.05) at 60 min of NI and decreased thereafter. Serum osmolality was constant (292 +/- 1 mosmol/kg) throughout NI, whereas PRA decreased progressively from 1.9 to 0.5 ng angiotensin I X ml-1 X h-1 (P less than 0.05) at theend of immersion. In spite of moderate thirst just before NI, thirst sensations were attenuated and no water was consumed ad libitum during immersion. These data indicate that PVP is not suppressed whenthere is no fluid intake during immersion and suggest that the action of factors other than PVP suppression are necessary to explain the mechanism of immersion diuresis.


Obesity Facts ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 307-321
Author(s):  
Clint T. Miller ◽  
Steve F. Fraser ◽  
Steve E. Selig ◽  
Toni Rice ◽  
Mariee Grima ◽  
...  

<b><i>Introduction:</i></b> To determine whether combined exercise training with an energy-restricted diet leads to improved physical fitness and body composition when compared to energy restriction alone in free-living premenopausal women with clinically severe obesity. <b><i>Methods:</i></b> Sixty premenopausal women (BMI of 40.4 ± 6.7) were randomised to energy restriction only (ER) or to exercise plus energy restriction (EXER) for 12 months. Body composition and fitness were measured at baseline, 3, 6 and 12 months. <b><i>Results:</i></b> VO<sub>2 peak</sub> improved more for EXER compared to ER at 3 (mean difference ± SEM 2.5 ± 0.9 mL ∙ kg<sup>–1</sup> ∙ min<sup>–1</sup>, <i>p</i> = 0.006) and 6 (3.1 ± 1.2 mL ∙ kg<sup>–1</sup> ∙ min<sup>–1</sup>, <i>p</i> = 0.007) but not 12 months (2.3 ± 1.6 mL ∙ kg<sup>–1</sup> ∙ min<sup>–1</sup>, <i>p</i> = 0.15). Muscle strength improved more for EXER compared to ER at all time points. No differences between groups for lean mass were observed at 12 months. <b><i>Conclusion:</i></b> Combining exercise training with an energy-restricted diet did not lead to greater aerobic power, total body mass, fat mass or limit lean body mass loss at 12 months when compared to energy restriction alone for premenopausal women with clinically severe obesity in free-living situations. Future research should aim to determine an effective lifestyle approach which can be applied in the community setting for this high-risk group.


2009 ◽  
Vol 21 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Beat Knechtle ◽  
Tristan Vinzent ◽  
Steve Kirby ◽  
Patrizia Knechtle ◽  
Thomas Rosemann

The Recovery Phase Following a Triple Iron TriathlonThe purpose of this case study was to investigate the recovery phase in a single athlete after a Triple Iron Triathlon involving 11.4 km swimming, 540 km cycling and 126.6 km running. Total body mass, body fat and skeletal muscle mass using the anthropometric method as well as total body water using bioelectrical impedance analysis were determined pre race, after the race and every 24 hours until complete recovery. Parameters of hydration status (urinary specific gravity, hematocrit and plasma sodium) and skeletal muscle damage (plasma urea) were measured at the same time. After finishing the race within 42 hours, total body mass was decreased and total body water was increased. Over the following 6 days, prior to returning to pre race values for plasma volume and total body water, body mass reached a peak value on day 3, plasma volume on day 2 and total body water on day 1. Clinically visible edemas of the feet persisted until day 4. Six days after the race, body mass was reduced by 2.1 kg, skeletal muscle mass by 0.6 kg and fat mass by 0.7 kg. An increase in both blood urea and urinary output post race between days 3 and 6 suggested an impairment of renal function immediately post race due to skeletal muscle damage and manifesting clinically observed edemas. For practical application, athletes, coaches and physicians should anticipate that performing such an ultra-endurance race can lead to considerable edemas of the lower limbs during the recovery phase.


2021 ◽  
Vol 12 ◽  
Author(s):  
Omar Andrade-Mayorga ◽  
Nicolás Martínez-Maturana ◽  
Luis A. Salazar ◽  
Erik Díaz

Background: Human adaptive response to exercise interventions is often described as group average and SD to represent the typical response for most individuals, but studies reporting individual responses to exercise show a wide range of responses.Objective: To characterize the physiological effects and inter-individual variability on fat mass and other health-related and physical performance outcomes after 12 weeks of high-intensity interval training (HIIT) and dietary energy restriction in overweight/obese adult women.Methods: Thirty untrained adult overweight and obese women (age = 27.4 ± 7.9 years; BMI = 29.9 ± 3.3 kg/m2) successfully completed a 12-week supervised HIIT program and an individually prescribed home hypocaloric diet (75% of daily energy requirements) throughout the whole intervention. High and low responders to the intervention were those individuals who were able to lose ≥ 10 and &lt; 10% of initial absolute fat mass (i.e., kilograms), respectively.Results: The prevalence for high and low responders was 33% (n = 11) and 66% (n = 19), respectively. At the whole group level, the intervention was effective to reduce the absolute fat mass (30.9 ± 7.2 vs. 28.5 ± 7.2 kg; p &lt; 0.0001), body fat percentage (39.8 ± 4.3 vs. 37.8 ± 4.9%; p &lt; 0.0001), and total body mass (76.7 ± 10.1 vs. 74.4 ± 9.9 kg; p &lt; 0.0001). In addition, there were improvements in systolic blood pressure (SBP; Δ% = −5.1%), diastolic blood pressure (DBP; Δ% = −6.4%), absolute VO2peak (Δ% = +14.0%), relative VO2peak (Δ% = +13.8%), peak power output (PPO; Δ% = +19.8%), anaerobic threshold (AT; Δ% = +16.7%), maximal ventilation (VE; Δ% = +14.1%), and peak oxygen pulse (O2 pulse; Δ% = +10.4%). However, at the individual level, a wide range of effects were appreciated on all variables, and the magnitude of the fat mass changes did not correlate with baseline body mass or fat mass.Conclusion: A 12-week supervised HIIT program added to a slight dietary energy restriction effectively improved fat mass, body mass, blood pressure, and cardiorespiratory fitness (CRF). However, a wide range of inter-individual variability was observed in the adaptative response to the intervention. Furthermore, subjects classified as low responders for fat mass reduction could be high responders (HiRes) in many other health-related and physical performance outcomes. Thus, the beneficial effects of exercise in obese and overweight women go further beyond the adaptive response to a single outcome variable such as fat mass or total body mass reduction.


Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2349
Author(s):  
Stephen Keenan ◽  
Matthew B. Cooke ◽  
Regina Belski

Diets utilising intermittent fasting (IF) as a strategic method to manipulate body composition have recently grown in popularity, however, dietary practices involving fasting have also been followed for centuries for religious reasons (i.e., Ramadan). Regardless of the reasons for engaging in IF, the impacts on lean body mass (LBM) may be detrimental. Previous research has demonstrated that resistance training promotes LBM accrual, however, whether this still occurs during IF is unclear. Therefore, the objective of this review is to systematically analyse human studies investigating the effects of variations of IF combined with resistance training on changes in LBM in previously sedentary or trained (non-elite) individuals. Changes in body weight and fat mass, and protocol adherence were assessed as a secondary objective. This review followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. MEDLINE, CINAHL, PubMed and SportDiscus databases were searched for articles investigating IF, combined with resistance training that reported measures of body composition. Eight studies met the eligibility criteria. LBM was generally maintained, while one study reported a significant increase in LBM. Body fat mass or percentage was significantly reduced in five of eight studies. Results suggest that IF paired with resistance training generally maintains LBM, and can also promote fat loss. Future research should examine longer-term effects of various forms of IF combined with resistance training compared to traditional forms of energy restriction. Prospero registration CRD42018103867.


2021 ◽  
pp. 089011712110291
Author(s):  
Puneet Kaur Chehal ◽  
Livvy Shafer ◽  
Solveig Argeseanu Cunningham

Purpose: This study contributes to the growing literature on the association between sleep and obesity by examining the associations between hours of sleep, consistency of bedtime, and obesity among children in the US. Design: Analysis of a nationally representative sample of non-institutionalized children from the 2016-17 National Survey of Children’s Health. Setting: US, national. Subjects: Children ages 10-17 years (n = 34,640) Measures: Parent reported weeknight average hours of sleep and consistency of bedtime. Body mass index classified as underweight, normal, overweight or obesity using parent-reported child height and weight information, classified using CDC BMI-for-Age Growth Charts. Analysis: Multivariate logistic regression models were used to estimate associations between measures of sleep and body mass index weight category adjusting for individual, household and neighborhood characteristics. Results: An additional hour of sleep was associated with 10.8% lower odds of obesity, net of consistency in bedtime. After controlling for sleep duration, children who usually went to bed at the same time on weeknights had lower odds of obesity (24.8%) relative to children who always went to bed at the same time. Conclusion: Sleep duration is predictive of lower odds of obesity in US children and adolescents. Some variability in weeknight bedtime is associated with lower odds of obesity, though there were no additional benefits to extensive variability in bedtime.


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