Hydration Recommendations for Sport 2008

Musculoskeletal injuries in UK Service Personnel and the impact of in-theatre rehabilitation during Cold Weather Warfare training: Exercise CETUS 2020

INTRODUCTION

The Royal Marines provide the lead Service for UK Defence Mountain and Cold Weather Warfare capability. This is the first prospective study addressing musculoskeletal injury rates sustained during Cold Weather Warfare training, with the aim of informing injury mitigation interventions and assist military medical planning with respect to delivering primary care rehabilitation in theatre.

METHODS

All musculoskeletal injuries were surveyed by the Forward Rehabilitation Team (Nov 2019-Mar 2020) during a Cold Weather Deployment to Norway (Ex CETUS 2019/20). The frequency, nature of injury (new or recurrent), onset (sudden or gradual), cause, location and exercise/treatment outcome were recorded.

RESULTS

Eleven per cent (n=136 cases) of the deployed population (n=1179) reported a musculoskeletal injury, which were mainly 'new' (62%), and with a 'sudden' onset (64%). Injury rate was 17.8 injuries per 10 000 personnel days. The majority of injuries occurred due to military training (88%), specifically during ski-related (61%) and load carriage (10%) activities.The average Service Person treated by the Forward Rehabilitation Team improved from 'injured with restricted duties' to 'fully fit', and with an improvement in their self-reported Musculoskeletal Health Questionnaire from 33 to 45 over an average of two rehabilitation sessions. One hundred and seventeen Service Personnel were able to continue on Ex CETUS with rehabilitation in theatre, thus negating the requirement for aeromedical evacuation for continuation of rehabilitation in the UK. Nineteen patients were unable to continue their Cold Weather Deployment due to the nature of their musculoskeletal injury and returned to the UK for continued care in firm base rehabilitation centres.

CONCLUSION

This study identifies the nature, causation and injury location. It demonstrates the effectiveness of in-theatre rehabilitation and the ability to treat patients when deployed. Recommendations are presented to support strategies to mitigate musculoskeletal injury risk during future Cold Weather Warfare deployments to Norway.

The Search for the Elixir of Life: On the Therapeutic Potential of Alkaline Reduced Water in Metabolic Syndromes

Our body composition is enormously influenced by our lifestyle choices, which affect our health and longevity. Nutrition and physical activities both impact overall metabolic condition, thus, a positive energy balance causes oxidative stress and inflammation, hastening the development of metabolic syndrome. With this knowledge, boosting endogenous and exogenous antioxidants has emerged as a therapeutic strategy for combating metabolic disorders. One of the promising therapeutic inventions is the use of alkaline reduced water (ARW). Aside from its hydrating and non-caloric properties, ARW has demonstrated strong antioxidant and anti-inflammatory properties that can help stabilize physiologic turmoil caused by oxidative stress and inflammation. This review article is a synthesis of studies where we elaborate on the intra- and extracellular effects of drinking ARW, and relate these to the pathophysiology of common metabolic disorders, such as obesity, diabetes mellitus, non-alcoholic fatty liver disease, and some cancers. Highlighting the health-promoting benefits of ARW, we also emphasize the importance of maintaining a healthy lifestyle by incorporating exercise and practicing a balanced diet as forms of habit.

Proposed framework for forecasting heat-effects on motor-cognitive performance in the Summer Olympics

Heat strain impairs performance across a broad spectrum of sport disciplines. The impeding effects of hyperthermia and dehydration are often ascribed to compromised cardiovascular and muscular functioning, but expert performance also depends on appropriately tuned sensory, motor and cognitive processes. Considering that hyperthermia has implications for central nervous system (CNS) function and fatigue, it is highly relevant to analyze how heat stress forecasted for the upcoming Olympics may influence athletes. This paper proposes and demonstrates the use of a framework combining expected weather conditions with a heat strain and motor-cognitive model to analyze the impact of heat and associated factors on discipline- and scenario-specific performances during the Tokyo 2021 games. We pinpoint that hyperthermia-induced central fatigue may affect prolonged performances and analyze how hyperthermia may impair complex motor-cognitive performance, especially when accompanied by either moderate dehydration or exposure to severe solar radiation. Interestingly, several short explosive performances may benefit from faster cross-bridge contraction velocities at higher muscle temperatures in sport disciplines with little or no negative heat-effect on CNS fatigue or motor-cognitive performance. In the analyses of scenarios and Olympic sport disciplines, we consider thermal impacts on “motor-cognitive factors” such as decision-making, maximal and fine motor-activation as well as the influence on central fatigue and pacing. From this platform, we also provide perspectives on how athletes and coaches can identify risks for their event and potentially mitigate negative motor-cognitive effects for and optimize performance in the environmental settings projected.

Efficacy of "optimal hydration" during labor: HYDRATA study protocol for a randomized clinical trial

There is a lack of consensus in the international scientific community with respect to the most suitable hydration strategies when attending nulliparous women during low-risk births. This paper describes the protocol for a randomized controlled trial to compare two hydration strategies and their influence on maternal and neonatal morbidity. The study population consists of nulliparous women admitted to the obstetrics department of a University Hospital. The women are being randomized into two groups: the "optimal hydration" group, which will be guaranteed 300 ml/hr liquids (crystalloids and bottled mineral water) with a minimum diuresis of 35 ml/hr; and the "variability in hydration" group, which will receive intravenous (alternating normal saline, Ringer's lactate solution, glucose, or Voluven®) and clear (bottled mineral water or isotonic drinks [Aquarius®]) liquids, without any established perfusion rate, and without established minimum diuresis. Outcomes for mothers include duration of labor, cesarean section, fever, and dehydration. Outcomes for newborns are respiratory distress, hypoglycemia, hyponatremia, jaundice, weight loss over 48 hr, and breastfeeding difficulties. Analysis will be per-protocol. Administering optimal hydration may improve health and safety for mothers and their newborn and reduce maternal and neonatal morbidity. The study is registered at www.clinicaltrials.gov. The project received funding by the Ministry of Health of Spain and is approved by the Research Ethics Committee.

The effect of mineral-based alkaline water on hydration status and the metabolic response to short-term anaerobic exercise

Previously it was demonstrated that mineralization and alkalization properties of mineral water are important factors influencing acid-base balance and hydration in athletes. The purpose of this study was to investigate the effects of drinking different types of water on urine pH, specific urine gravity, and post-exercise lactate utilization in response to strenuous exercise. Thirty-six male soccer players were divided into three intervention groups, consuming around 4.0 l/day of different types of water for 7 days: HM (n=12; highly mineralized water), LM (n=12; low mineralized water), and CON (n=12; table water). The athletes performed an exercise protocol on two occasions (before and after intervention). The exercise protocol consisted of 5 bouts of intensive 60-s (120% VO_2max) cycling separated by 60 s of passive rest. Body composition, urinalysis and lactate concentration were evaluated – before (t0), immediately after (t1), 5’ (t2), and 30’ (t3) after exercise. Total body water and its active transport (TBW – total body water / ICW – intracellular water / ECW – extracellular water) showed no significant differences in all groups, at both occasions. In the post-hydration state we found a significant decrease of specific urine gravity in HM (1021±4.2 vs 1015±3.8 g/L) and LM (1022±3.1 vs 1008±4.2 g/L). We also found a significant increase of pH and lactate utilization rate in LM. In conclusion, the athletes hydrated with alkaline, low mineralized water demonstrated favourable changes in hydration status in response to high-intensity interval exercise with a significant decrease of specific urine gravity, increased urine pH and more efficient utilization of lactate after supramaximal exercise.

Heat strain evaluation of overt and covert body armour in a hot and humid environment

The aim of this study was to elucidate the thermophysiological effects of wearing lightweight non-military overt and covert personal body armour (PBA) in a hot and humid environment. Eight healthy males walked on a treadmill for 120 min at 22% of their heart rate reserve in a climate chamber simulating 31 °C (60%RH) wearing either no armour (control), overt or covert PBA in addition to a security guard uniform, in a randomised controlled crossover design. No significant difference between conditions at the end of each trial was observed in core temperature, heart rate or skin temperature (P > 0.05). Covert PBA produced a significantly greater amount of body mass change (-1.81 ± 0.44%) compared to control (-1.07 ± 0.38%, P = 0.009) and overt conditions (-1.27 ± 0.44%, P = 0.025). Although a greater change in body mass was observed after the covert PBA trial; based on the physiological outcome measures recorded, the heat strain encountered while wearing lightweight, non-military overt or covert PBA was negligible compared to no PBA.

PRACTITIONER SUMMARY

The wearing of bullet proof vests or body armour is a requirement of personnel engaged in a wide range of occupations including police, security, customs and even journalists in theatres of war. This randomised controlled crossover study is the first to examine the thermophysiological effects of wearing lightweight non-military overt and covert personal body armour (PBA) in a hot and humid environment. We conclude that the heat strain encountered while wearing both overt and covert lightweight, non-military PBA was negligible compared to no PBA.

Evidence-informed physical therapy management of performance-related musculoskeletal disorders in musicians

Playing a musical instrument at an elite level is a highly complex motor skill. The regular daily training loads resulting from practice, rehearsals and performances place great demands on the neuromusculoskeletal systems of the body. As a consequence, performance-related musculoskeletal disorders (PRMDs) are globally recognized as common phenomena amongst professional orchestral musicians. These disorders create a significant financial burden to individuals and orchestras as well as lead to serious consequences to the musicians’ performance and ultimately their career. Physical therapists are experts in treating musculoskeletal injuries and are ideally placed to apply their skills to manage PRMDs in this hyper-functioning population, but there is little available evidence to guide specific injury management approaches. An Australia-wide survey of professional orchestral musicians revealed that the musicians attributed excessively high or sudden increase in playing-load as major contributors to their PRMDs. Therefore, facilitating musicians to better manage these loads should be a cornerstone of physical therapy management. The Sound Practice orchestral musicians work health and safety project used formative and process evaluation approaches to develop evidence-informed and clinically applicable physical therapy interventions, ultimately resulting in favorable outcomes. After these methodologies were employed, the intervention studies were conducted with a national cohort of professional musicians including: health education, onsite injury management, cross-training exercise regimes, performance postural analysis, and music performance biomechanics feedback. The outcomes of all these interventions will be discussed alongside a focussed review on the existing literature of these management strategies. Finally, a framework for best-practice physical therapy management of PRMDs in musicians will be provided.

Aluminium in human sweat

It is of burgeoning importance that the human body burden of aluminium is understood and is measured. There are surprisingly few data to describe human excretion of systemic aluminium and almost no reliable data which relate to aluminium in sweat. We have measured the aluminium content of sweat in 20 healthy volunteers following mild exercise. The concentration of aluminium ranged from 329 to 5329μg/L. These data equate to a daily excretion of between 234 and 7192μg aluminium and they strongly suggest that perspiration is the major route of excretion of systemic aluminium in humans.

Cardiorespiratory effects of water ingestion during and after exercise

BACKGROUND

In prolonged exercise, the state of hypohydration due to sweating raises physiological stress and induces a drop in sports performance. However, the impact of water intake in cardiorespiratory parameters when administered during and after physical activity has not been well studied. This study aimed to analyze the effects of water intake in heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), partial oxygen saturation (SpO2) and respiratory rate during and after prolonged exercise.

METHODS

Thirty-one young males (21.55 ± 1.89 yr) performed three different protocols (48 h interval between each stage): I) maximal exercise test to determine the load for the protocols; II) Control protocol (CP) and; III) Experimental protocol (EP). The protocols consisted of 10 min at rest with the subject in the supine position, 90 min of treadmill exercise (60% of VO2 peak) and 60 min of rest placed in the dorsal decubitus position. No rehydration beverage consumption was allowed during CP. During EP, however, the subjects were given water (Vittalev, Spaipa, Brazil). The parameters HR, SBP, DBP, SpO2 and respiratory rate were measured at the end of the rest, in 30, 60 and 90 minutes of the activity, except the respiratory rate parameter, and at 1, 3, 5, 7, 10, 20, 30, 40, 50 and 60 minute post- exercise.

RESULTS

The hydration protocol provided minimal changes in SBP and DBP and a smaller increase in HR and did not significantly affect SpO2 during exercise and better HR recovery, faster return of SBP and DBP and a better performance for SpO2 and respiratory rate post-exercise.

CONCLUSION

Hydration with water influenced the behavior of cardiorespiratory parameters in healthy young subjects.

Effects of different protocols of hydration on cardiorespiratory parameters during exercise and recovery

INTRODUCTION

Hydration plays a key role in the physiological maintenance required by exercise.

OBJECTIVE

To evaluate the behavior of heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure, pulse oxygen saturation (SpO2) and respiratory rate (RR) of young people during and after prolonged physical exercise, with and without the intake of water or isotonic solution.

METHOD

31 young individuals (21.63 ± 1.86 years) were subjected to a four-step protocol with a 48-hour interval between each step, namely: i) a test to determine the incremental load used in subsequent steps, ii) a control protocol without hydration (CP), iii) an experimental protocol with water intake (PE1), iv) an experimental protocol with ingestion of isotonic (PE2). The protocols consisted of 10 min rest, 90 min of exercise on a treadmill at 60% of VO2peak and 60 min of recovery. The parameters HR, SBP, DBP, RR and SPO2 were measured at rest, at 30, 60 and 90 min of exercise, with the exception of RR; and at 1, 3, 5, 7, 10, 20, 30, 40, 50 and 60 min of recovery. The two-factor analysis of variance for repeated measures model was used for analysis (p<0.05).

RESULTS

There was a moment effect for all variables in exercise (p<0.001), however, no effect was observed between the protocols (SBP, p=0.998; DBP, p=0.897; SpO2, p=0.077, HR=0.281) and in the interaction moment and protocol (SBP, p=0.058; DBP, p=0.191 and SpO2, p=0.510, HR=0.496). In recovery there was also a moment effect for all variables analyzed (p<0.001). There was no effect among protocols for SBP (p=0.986), DBP (p=0.536) and RR (p=0.539), however in the SpO2 (p=0.001) and HR (p=0.033) variables, effects were observed between the protocols. Regarding the moment and protocol interaction, an effect was observed for HR (SBP, p=0.431; DBP, p=0.086; SpO2, p=0.445, RR, p=0.147, HR, p=0.022).

CONCLUSION

For the type of exercise performed, both the water and the isotonic solution influenced the behavior of cardiorespiratory parameters, and independent of the type of hydration given the behavior of the parameters studied was similar.

Intravenous fluids for reducing the duration of labour in low risk nulliparous women

BACKGROUND

Several factors may influence the progression of normal labour. It has been postulated that the routine administration of intravenous fluids to keep women adequately hydrated during labour may reduce the period of contraction and relaxation of the uterine muscle, and may ultimately reduce the duration of the labour. It has also been suggested that intravenous fluids may reduce caesarean sections (CS) for prolonged labour. However, the routine administration of intravenous fluids to labouring women has not been adequately elucidated although it is a widely-adopted policy, and there is no consensus on the type or volume of fluids that are required, or indeed, whether intravenous fluids are at all necessary. Women may be able to adequately hydrate themselves if they were allowed oral fluids during labour.Furthermore, excessive volumes of intravenous fluids may pose risks to both the mother and her newborn and different fluids are associated with different risks.

OBJECTIVES

To evaluate whether the routine administration of intravenous fluids to low-risk nulliparous labouring women reduces the duration of labour and to evaluate the safety of intravenous fluids on maternal and neonatal health.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (13 February 2013).

SELECTION CRITERIA

Randomised controlled trials of intravenous fluid administration to spontaneously labouring low-risk nulliparous women.

DATA COLLECTION AND ANALYSIS

The review authors independently assessed trials for inclusion, trial quality and extracted data.

MAIN RESULTS

We included nine randomised trials with 1781 women. Three trials had more than two treatment arms and were included in more than one comparison.Two trials compared women randomised to receive up to 250 mL/hour of Ringer's lactate solution as well as oral intake versus oral intake only. For women delivering vaginally, there was a reduction in the duration of labour in the Ringer's lactate group (mean difference (MD) -28.86 minutes, 95% confidence interval (CI) -47.41 to -10.30). There was no statistical reduction in the number of CS in the Ringer's lactate group (risk ratio (RR), 0.73 95% CI 0.49 to 1.08).Three trials compared women who received 125 mL/hour versus 250 mL/hour of intravenous fluids with free oral fluids in both groups. Women receiving a greater hourly volume of intravenous fluids (250 mL) had shorter labours than those receiving 125 mL (MD 23.87 minutes, 95% CI 3.72 to 44.02, 256 women). There was no statistically significant reduction in the number of CS in the 250 mL intravenous fluid group (average RR 1.00, 95% CI 0.54 to1.87, three studies, 334 women). In one study the number of assisted vaginal deliveries was lower in the group receiving 125 mL/hour (RR 0.47, 95% CI 0.27 to 0.81).Four trials compared rates of intravenous fluids in women where oral intake was restricted (125 mL/hour versus 250 mL/hour). There was a reduction in the duration of labour in women who received the higher infusion rate (MD 105.61 minutes, 95% CI 53.19 to 158.02); P < 0.0001, however, findings must be interpreted with caution as there was high heterogeneity amongst trials (I(2) = 53%). There was a significant reduction in CS in women receiving the higher rate of intravenous fluid infusion (RR 1.56, 95% CI 1.10 to 2.21; P = 0.01). There was no difference identified in the assisted delivery rate (RR 0.78, 95% CI 0.44 to 1.40). There was no clear difference between groups in the number of babies admitted to the NICU (RR 0.48, 95% CI 0.07 to 3.17).Two trials compared normal saline versus 5% dextrose. Only one reported the mean duration of labour, and there was no strong evidence of a difference between groups (MD -12.00, 95% CI -30.09 to 6.09). A trial reporting the median suggested that the duration was reduced in the dextrose group. There was no significant difference in CS or assisted deliveries (RR 0.77, 95% CI 0.41 to 1.43, two studies, 284 women) and (RR 0.59, 95% CI 0.21 to 1.63, one study, 93 women) respectively. Only one trial reported on maternal hyponatraemia (serum sodium levels < 135 mmol/L ). For neonatal complications, there was no difference in the admission to NICU) or in low Apgar scores, however 33.3% of babies developed hyponatraemia in the dextrose group compared to 13.3 % in the normal saline group (RR 0.40, 95% CI 0.17 to 0.93) (P = 0.03). One trial reported a higher incidence of neonatal hyperbilirubinaemia in the dextrose group of babies. There was no difference in neonatal hypoglycaemic episodes between groups.

AUTHORS' CONCLUSIONS

Although the administration of intravenous fluids compared with oral intake alone demonstrated a reduction in the duration of labour, this finding emerged from only two trials. The findings of other trials suggest that if a policy of no oral intake is applied, then the duration of labour in nulliparous women may be shortened by the administration of intravenous fluids at a rate of 250 mL/hour rather than 125 mL/hour. However, it may be possible for women to simply increase their oral intake rather than being attached to a drip and we have to consider whether it is justifiable to persist with a policy of 'nil by mouth'. One trial raised concerns about the safety of dextrose and this needs further exploration.None of the trials reported on the evaluation of maternal views of being attached to a drip during their entire labour. Furthermore, there was no objective assessment of dehydration. The evidence from this review does not provide robust evidence to recommend routine administration of intravenous fluids. Interpreting the results from trials was hampered by the low number of trials contributing data and by variation between trials. In trials where oral fluids were not restricted there was considerable variation in the amount of oral fluid consumed by women in different arms of the same trial, and between different trials. In addition, results from trials were not consistent and risk of bias varied. Some important research questions were addressed by single trials only, and important outcomes relating to maternal and infant morbidity were frequently not reported.

Lack of awareness of fluid needs among participants at a midwest marathon

BACKGROUND

Marathon running has become popular, particularly among inexperienced runners.

HYPOTHESIS

Many marathoners are inexperienced and lack concern for potential complications of marathon running.

STUDY DESIGN

Cross-sectional survey.

METHODS

In sum, 419 runners completed a survey on a variety of topics regarding training for a marathon and hydration strategies.

RESULTS

Overall, 211 females (38.3 ± 9.1 years old) and 208 males (41.6 ± 11.0 years old) participated. They trained for 6.8 ± 4.3 months and had run for 9.8 ± 9.1 years; 33.5% had no marathon experience and 16.9% had run 1 marathon. Of the injuries reported, 77.6% and 72.9% were minor musculoskeletal injuries during the current and previous running seasons, respectively. Of the 278 runners who had run a marathon, 54 (19.0%) had been treated in the medical tent, 31.5% of whom for dehydration. Furthermore, 54.9% and 64.3% of the survey participants were "not at all" concerned with musculoskeletal injury and hyponatremia, respectively. Also, 88.7% did not know their sweat rate; 67.8% did not weigh themselves; and 81.3% had no other method of hydration assessment. No significant correlations were found between concern for hyponatremia and age, sex, or experience.

CONCLUSIONS

Most participants were inexperienced, lacked concern for injury or hyponatremia, and were not using methods of hydration assessment.

Supplementation of Acqua Lete® (Bicarbonate Calcic Mineral Water) improves hydration status in athletes after short term anaerobic exercise

BACKGROUND

Experimental studies suggest that mineral waters with high concentrations of calcium and bicarbonate can impact acid-base balance. The purpose of this study was to test the effect on acid-base balance and specific urine gravity, of a bicarbonate calcic mineral water (Acqua Lete®) compared to a minimally mineralized water.

METHODS

88 amateur male athletes underwent two experimental trials with a modified Wingate test: the first was carried out without hydration (Control Test, Test C, n = 88); the second was carried out after one week of controlled hydration (Test with hydration, Test H, n = 88), with 1.5 L/day of a very low mineral content water (Group A, n = 44) or 1.5 L/day of Acqua Lete® (Group B, n = 44). Measure of body temperature, bioimpedance analysis, muscular ultrasound, and urinalysis were taken before (t0), immediately after (t1), 5' (t2), and 30' (t3) after exercise.

RESULTS

Hydration results in a decreased core temperature; muscular ultrasound showed increased muscle thickness after exercise related to content of body water. Regarding urinalysis, in test H, we found in both groups after exercise a significant decrease of specific urine gravity with significantly lower levels in Group B. We also found a significant increase of pH in the same Group B.

CONCLUSIONS

In conclusion all the athletes hydrated with Acqua Lete® showed a positive impact on hydration status after anaerobic exercise with significant decrease of specific urine gravity and a positive effect on pH.

Efeitos da reposição hidroeletrolítica sobre parâmetros cardiorrespiratórios em exercício e recuperação

INTRODUÇÃO: a necessidade de reposição ao máximo das perdas hídricas tornou-se estabelecida e difundida nos consensos internacionais. Entretanto, permanece pouco compreendida a influência da reposição quando administrada, igualmente, durante e após o exercício sobre parâmetros cardiorrespiratórios. OBJETIVO: analisar os efeitos da reposição hidroeletrolítica na frequência cardíaca (FC), pressão arterial sistólica (PAS), pressão arterial diastólica (PAD), saturação parcial de oxigênio (SpO2) e frequência respiratória (f) de jovens durante e após um exercício de longa duração. MÉTODOS: 31 jovens (21,55 ± 1,89 anos) realizaram três visitas ao laboratório (intervalo de 48 horas entre elas), sendo na primeira aplicado um teste incremental, para determinação da carga utilizada nas visitas seguintes, e nas duas últimas, denominadas protocolo controle (PC) e protocolo experimental (PE), os sujeitos foram submetidos a 10 min de repouso supino, 90 min de exercício em esteira ergométrica (60% do VO2pico) e 60 min de repouso supino. No PC não houve hidratação e no PE houve ingestão de solução isotônica. Os parâmetros FC, PAS, PAD, SpO2 e f foram mensurados no final do repouso; nos minutos 30, 60 e 90 do exercício, com exceção da f; e nos minutos 1, 3, 5, 7, 10, 20, 30, 40, 50 e 60 pós-exercício. Foi aplicado o teste t de Student ou teste de Mann-Whitney e ANOVA para medidas repetidas ou teste de Friedman seguidos de testes post hoc, com p < 0,05. RESULTADOS: a solução hidroeletrolítica proporcionou manutenção da PAS e da PAD, e menor incremento da FC durante o exercício; e promoveu retorno mais rápido da FC e conservou PAD, SpO2, PAS (a partir do 5º min) e f (a partir do 30º min) no período de recuperação. CONCLUSÃO: o protocolo de hidratação influenciou parâmetros cardiorrespiratórios de jovens durante e após a realização de atividade física submáxima de intensidade constante e longa duração.

Sports drinks and energy drinks for children and adolescents: are they appropriate?

Sports and energy drinks are being marketed to children and adolescents for a wide variety of inappropriate uses. Sports drinks and energy drinks are significantly different products, and the terms should not be used interchangeably. The primary objectives of this clinical report are to define the ingredients of sports and energy drinks, categorize the similarities and differences between the products, and discuss misuses and abuses. Secondary objectives are to encourage screening during annual physical examinations for sports and energy drink use, to understand the reasons why youth consumption is widespread, and to improve education aimed at decreasing or eliminating the inappropriate use of these beverages by children and adolescents. Rigorous review and analysis of the literature reveal that caffeine and other stimulant substances contained in energy drinks have no place in the diet of children and adolescents. Furthermore, frequent or excessive intake of caloric sports drinks can substantially increase the risk for overweight or obesity in children and adolescents. Discussion regarding the appropriate use of sports drinks in the youth athlete who participates regularly in endurance or high-intensity sports and vigorous physical activity is beyond the scope of this report.

Changes in total body water content during running races of 21.1 km and 56 km in athletes drinking ad libitum

OBJECTIVE

To measure changes in body mass (BM), total body water (TBW), fluid intake, and blood biochemistry in athletes during 21.1-km and 56-km foot races.

DESIGN

Observational study.

SETTING

2009 Two Oceans Marathon, South Africa.

PARTICIPANTS

Twenty-one (21.1 km) and 12 (56 km) participants were advised to drink according to thirst or their own race drink plan (ad libitum).

MAIN OUTCOME MEASURES

Body mass, TBW, plasma osmolality, plasma sodium (p[Na]), and plasma total protein ([TP]) concentrations were measured before and after race. Fluid intake was recorded from recall after race.

RESULTS

Significant BM loss occurred in both races (21.1 km; -1.4 ± 0.6 kg; P < 0.000 and 56 km; -2.5 ± 1.1 kg; P < 0.000). Total body water was reduced in the 56-km race (-1.4 ± 1.1 kg; P < 0.001). A negative linear relationship was found between percentage change (%Δ) in TBW and %Δ in BM in the 56-km runners (r = 0.6; P < 0.01). Plasma osmolality and [TP] increased significantly in the 56-km runners (6.8 ± 8.2 mOsm/kg H2O; P < 0.05 and 5.4 ± 4.4 g/L; P < 0.01, respectively), but all other biochemical measures were within the normal range.

CONCLUSIONS

Although TBW decreased in the 56-km race and was maintained in the 21.1-km race, the change in TBW over both races was less than the BM, suggesting that not all BM lost during endurance exercise is a result purely of an equivalent reduction in TBW. These findings support the interpretation that the body primarily defends p[Na] and not BM during exercise and that a reduction in BM can occur without an equivalent reduction in TBW during prolonged exercise. Furthermore, these data support that drinking without controlling for BM loss may allow athletes to complete these events.

Influence of hydration volume and ambient temperature on physiological responses while wearing CBRN protective clothing

This study examined a low (L; 5 ml/kg per h) and high (H, 10 ml/kg per h) rate of fluid replacement in moderate (18°C) and hot (30°C) conditions on physiological responses while wearing personal protective equipment (PPE). PPE included the gas-tight suit (GTS), the powered respirator protective suit (PRPS) and the civil responder 1 (CR1). Relative to the moderate condition, physiological responses were greater in the hot condition. The percentage change in body mass was different (p < 0.05) between L and H in the hot (L vs. H, GTS: -0.83 vs. -0.38%; PRPS: -1.18 vs. -0.71%; CR1: -1.62 vs. -0.57%) and moderate conditions, although in GTS and CR1 body mass increased (L vs. H, GTS: -0.48 vs. 0.06%; PRPS: -0.66 vs. -0.11%; CR1: -0.18 vs. 0.67%). Fluid replacement strategies for PPE should be adjusted for environmental conditions in order to avoid >1% body mass loss and/or net body mass gain. STATEMENT OF RELEVANCE: Currently, the UK Emergency Services do not have specific evidence-based fluid replacement guidelines to follow when wearing chemical, biological, radiological and/or nuclear (CBRN) PPE. Although ad libitum fluid replacement is encouraged (when breathing apparatus permits), recommendations from evidence-based findings specific to different PPE and to different environmental conditions are lacking. This study provides novel evidence supporting the need to develop fluid replacement strategies during CBRN deployments in both moderate and hot environmental conditions for CBRN PPE.

BIOTEX--biosensing textiles for personalised healthcare management

Textile-based sensors offer an unobtrusive method of continually monitoring physiological parameters during daily activities. Chemical analysis of body fluids, noninvasively, is a novel and exciting area of personalized wearable healthcare systems. BIOTEX was an EU-funded project that aimed to develop textile sensors to measure physiological parameters and the chemical composition of body fluids, with a particular interest in sweat. A wearable sensing system has been developed that integrates a textile-based fluid handling system for sample collection and transport with a number of sensors including sodium, conductivity, and pH sensors. Sensors for sweat rate, ECG, respiration, and blood oxygenation were also developed. For the first time, it has been possible to monitor a number of physiological parameters together with sweat composition in real time. This has been carried out via a network of wearable sensors distributed around the body of a subject user. This has huge implications for the field of sports and human performance and opens a whole new field of research in the clinical setting.