Hydration of the Human Body Is the body nearly 75% water as often stated? – In fact, lean tissue (fat-free mass) is about 73% water – The whole body is roughly 50% to 65% water Leaner individuals having the higher water percentage Fat mass contains very little water – The more adipose tissue, the lower the water percentage The roles and significance of water in the body – Gives form and substance to body – Lubricates joints – Transports nutrients and waste (eg, blood is nearly 80% water) – Provides a medium for metabolism – Is a reactant in or product of metabolic reactions – Is a major factor in heat dissipation Cardiovascular system – cardiac output Thermoregulation – skin blood flow and sweat 3 Casa DJ, et al. J Athl Train. 2000;35(2):
Fluids and Electrolytes: Hydration for Physical Activity and
Sport Advanced Module 1 Learning Objectives of the Course After
completing this module, participants will be able to Understand
significance of water in the human body Explain the process of
thermoregulation during exercise Describe the sweat mechanism and
reason for electrolyte losses in the water of sweat Recognize and
reduce the risk of heat illnesses by stating the symptoms,
contributing factors, and strategies for prevention Estimate
appropriate fluid replacement needs and hydration strategies
Discuss several specific concerns and apply strategies to help
prevent their occurrence during exercise in the heat Dehydration
Hyponatremia 2 Hydration of the Human Body Is the body nearly 75%
water as often stated? In fact, lean tissue (fat-free mass) is
about 73% water The whole body is roughly 50% to 65% water Leaner
individuals having the higher water percentage Fat mass contains
very little water The more adipose tissue, the lower the water
percentage The roles and significance of water in the body Gives
form and substance to body Lubricates joints Transports nutrients
and waste (eg, blood is nearly 80% water) Provides a medium for
metabolism Is a reactant in or product of metabolic reactions Is a
major factor in heat dissipation Cardiovascular system cardiac
output Thermoregulation skin blood flow and sweat 3 Casa DJ, et al.
J Athl Train. 2000;35(2): Thermoregulation 4 Nadel ER, et al. Ann N
Y Acad Sci. 1977;301: Wilmore JH, et al. Physiology of Sport and
Exercise 4th edition. Champaign: Human Kinetics Publishers; 2008:
pp Effect of Exercise Increases metabolism and body heat production
Response to Exercise: Maintenance of Homeostasis Heat removal is
required Means of doing so include Conduction (Cd) Convection (Cv)
Radiation (R) Evaporation (E, via sweat) Cv R E Cd Quantifying the
Change in Heat Heat balance = M Cd Cv R E Where Metabolic rate (M)
contributes to heat gain Conductance (Cd) is considered to be zero
in application and is typically not used Convection (Cv) and
radiation (R) can be positive or negative (adding to or subtracting
from metabolic heat gain), depending on environmental temperature
vs the body Evaporation (E) is always negative (subtracting from
metabolic heat gain), reducing body temperature 5 Nadel ER, et al.
Ann N Y Acad Sci. 1977;301: Wilmore JH, et al. Physiology of Sport
and Exercise 4th edition. Champaign: Human Kinetics Publishers;
2008: pp Evaporation of Sweat Critical body cooling mechanism for
most physical activities 1 liter of sweat evaporated off the skin
dissipates 580 kcal of heat Must evaporate off the skin No
dissipation occurs when sweat drips off the body 6 Costill DL. Ann
N Y Acad Sci. 1977;301: Cheuvront SN, et al. Cur Sports Med Rep.
2003;2(4): Routes to Initiate and Discontinue Sweating Exercise
increases heat production Temperature of blood Thermoreceptors
sense temperature Input to CNS control center, preoptic anterior
hypothalamus, via Circulation of warmer blood temperature Afferent
signals thermoreceptors Hypothalamus stimulates response via the
SNS Sweat glands secrete fluid Arterioles in skin dilate
Thermoreceptors detect a reduced skin temperature, provide neural
feedback to hypothalamus 7 Abbreviations: CNS, central nervous
system; SNS, sympathetic nervous system. Crandall CG, et al. J.
Acta Physiol. 2010;199: Shibasaki M, et al. Front Biosci (Schol
Ed). 2011;2: Sweat Rate: A Function of Several Factors Environment
Temperature Humidity Fitness Heat acclimation Gender Genetics
Exercise intensity Clothing and equipment Average sweat rates,
L/hour Swimmers0.3 Motor-car athletes1.1 Yacht athletes1.3 Junior
hockey1.5 NFL players2.1 8 Brearley M, et al. Int J Sports Physiol
Perform. 2007;2(2): Godek SF, et al. J Athl Train. 2010;45(2):
Neville V, et al. Scand J Med Sci Sports. 2010;20(3): Maughan RJ,
et al. Int J Sport Nutr Exerc Metab. 2009;19(6): Palmer MS, et al.
Appl Physiol Nutr Metab. 2010;35(3): 9 Sweat Composition: More than
Just Water Sweat MineralsRange, mmol/L 1 Sodium Chloride Potassium4
- 8 Calcium0 - 1 Magnesium< 0.2 Factors affecting sweat
electrolyte concentration include sweat rate, state of heat
acclimatization, genetics, and gender. 1. Data from Maughan RJ. J
Sports Sci. 1991;9 Spec No: Electrolyte Loss in Sweat Sweat gland
function Draws water from plasma volume to make sweat Proteins,
other large compounds remain in blood Minerals move with the water
Reabsorbs minerals for conservation Reabsorption is not 100% When
rate and duration of sweat loss are extensive, replacement of water
and electrolytes is increasingly important. 10 H2O Na Cl K High
flow rate Na Cl K Heat dissipation Final Na +, Cl , K +, other
minerals in sweat Low flow rate Na Cl K Sweat Droplet Duct
Secretory coil Abbreviations: Na, sodium; Cl, chloride; K,
potassium. Sato K, et al. J Am Acad Dermatol. 1989;20(4): Clothing:
Barriers to Heat Dissipation Clothing such as gear and uniforms in
sports Retards the evaporation of sweat for heat dissipation Adds
insulation to increase heat retention Adds weight that can increase
work and heat production Rectal Temperature, C 11 After 30-minutes
rest in uniform, temp still above peak during exercise in t-shirt
Mathews DK, et al J Appl Physiol. 1969;26(5): In a classic study,
30 minutes of moderate intensity exercise on treadmill and 30
minutes of recovery showed Temperature increases during exercise
with increasing weight and clothing T-shirt and shorts (Clothes
only) Clothing + Weighted Backpack Football uniform (Wearing Gear)
Baseline temperature returns slower with increasing weight and
clothing Outcomes When Heat Production Is Not Offset During
Exercise Rapid increase in core temperature Risk of heat illnesses
Heat cramps Heat syncope Heat exhaustion Heat stroke 12 Wilmore JH,
et al. Physiology of Sport and Exercise 4th edition. Champaign:
Human Kinetics Publishers; 2008: pp American College of Sports
Medicine. Med Sci Sports Exerc. 2007;39(3): Heat Illnesses Factors
contributing to episodes of heat illnesses Intensity of exercise
Heat acclimation Fitness level Medications Supplements with ephedra
or other stimulants Environment Recent illness Hypohydration or
dehydration 13 Caution: Heat stroke can occur with little warning
or few associated factors being present Wilmore JH, et al.
Physiology of Sport and Exercise 4th edition. Champaign: Human
Kinetics Publishers; 2008: pp American College of Sports Medicine.
Med Sci Sports Exerc. 2007;39(3): Heat Cramps (Exercise Associated
Muscle Cramps) Definition: involuntary contractions and spasms of
skeletal muscle in association with intensity of exercise in the
heat Symptoms Twitching or tightening precedes the cramp Fatigue
Possibly nausea Contributing factors Muscle fatigue Large losses of
fluid and electrolytes (particularly sodium) Multiple and/or
prolonged competition within a day Treatment Stretching Rest
Replace fluids and electrolytes (orally or by intravenous infusion
depending on severity) 14 Wilmore JH, et al. Physiology of Sport
and Exercise 4th edition. Champaign: Human Kinetics Publishers;
2008: pp American College of Sports Medicine. Med Sci Sports Exerc.
2007;39(3): Heat Syncope Definition: orthostatic hypotension and
collapse in the heat, occurring as a result of heat exposure,
vasodilation, and lack of movement Symptoms Unconsciousness after
standing or stopping movement in a hot environment Contributing
factors Prolonged heat exposure, possibly while wearing excess
clothing Not necessarily large fluid losses Treatment Elevate legs
to restore blood flow to head Rest in a cool area to reduce body
temperature Possibly oral fluids, if dehydration appears to be a
factor 15 Wilmore JH, et al. Physiology of Sport and Exercise 4th
edition. Champaign: Human Kinetics Publishers; 2008: pp American
College of Sports Medicine. Med Sci Sports Exerc. 2007;39(3): Heat
Exhaustion Definition: inability to continue work or exercise in
the heat Symptoms Fatigue, weakness Irritable Headache Nausea or
vomiting Chills Low blood pressure and rapid pulse Core temperature
may be elevated, but 40 C is the definitive sign May have hot pale
skin Confusion or irrational behavior Hyperventilation (rapid
breathing) Vomiting Loss of consciousness Seizures Coma
Contributing factors Intense exercise in or exposure to the heat
Recent illness Use of certain medications Dehydration is likely,
but not necessary for HS to occur Treatment Immediate cooling such
as in an ice bath or ice packs Treat as a medical emergencycall
Medications thought to increase risk of heat stroke Diuretics Drugs
having diuretic actions - Ephedrine-containing medication - Ephedra
herb - Alcohol - Possibly caffeine and theophylline Wilmore JH, et
al. Physiology of Sport and Exercise 4th edition. Champaign: Human
Kinetics Publishers; 2008: pp American College of Sports Medicine.
Med Sci Sports Exerc. 2007;39(3): Effect of Dehydration on
Physiology Study involving 8 endurance-trained cyclists, with 4
sessions each Cycling at constant work load (~65% peak VO 2 ) for 2
hours in heat (32.7 o C) Randomized to different fluid replacement
treatments No fluid (4.2%) 20% of sweat loss (3.4%) 50% of sweat
loss (2.3%) 80% of sweat loss (1.1%) Thermoregulation and
cardiovascular responses follow in the next slides 18 Montain SJ,
et al. J Appl Physiol. 1992;73(4): [[AQ: PLEASE PROVIDE SOURCE FOR
PICTURE.]] Thermoregulatory Response to Replacement Fluids:
Temperature Reprinted from Montain SJ, et al. J Appl Physiol.
1992;73(4): Thermoregulatory Response to Replacement Fluids: Blood
Flow -4.2% -1.1% Reprinted from Montain SJ, et al. J Appl Physiol.
1992;73(4): Cardiovascular Response to Replacement Fluids: Heart
Rate -1.1% -4.2% Reprinted from Montain SJ, et al. J Appl Physiol.
1992;73(4): Cardiovascular Response to Replacement Fluids: Cardiac
Output -1.1% -4.2% Reprinted from Montain SJ, et al. J Appl
Physiol. 1992;73(4): Summary of Dehydration Effects Impaired
cardiovascular function 1 Impaired heat dissipation 2 Elevated
ratings of perceived exertion 2 Starting at 2% dehydration, 2-7
Physical endurance is reduced Cognitive function is impaired
Crandall CG, et al. J. Acta Physiol. 2010;199: Murray B. J Am Coll
Nutr. 2007;26(5 suppl):542S-548S. 3. Lieberman HR. J Am Coll Nutr.
2007;26(5 suppl):555S-561S. 4. Grandjean AC, et al. J Am Coll Nutr.
2007;26(5):549S-554S. 5. Casa DJ, et al. J Athl Train. 2010;45(2):
Gopinathan PM, et al. Arch Environ Health. 1988;43(1): Judselson
DA, et al. Sports Med. 2007;37(10): Thirst Mechanism Defends
Against Dehydration Fluid loss from plasma volume Reduces blood
pressure Increases plasma osmolality Nervous system detects changes
Baroreceptors sense drop in pressure Chemoreceptors sense rise in
osmolality Receptors in CV system signal hypothalamus Registers as
thirst Stimulates behavior to drink and restore plasma volume
Replacement is not perfect For reasons yet unknown, humans
typically stop drinking during exercise before replacing 100% of
fluid lost Potential reasons for gap in drinking response Allows
humans to override the thirst response when other physical danger
is imminent Inadequate response may help prevent acute hyponatremia
24 Greenleaf JE. Med Sci Sports Exerc. 1992;24(6): Hyponatremia 25
Defined as Plasma blood sodium level < 135 mmol/L Normal range,
136 to 142 mmol/L Symptoms Headache Coma and/or death from shifts
in water into brain cells Risk Factors Over drinking, weight gain
during exercise Small body mass Back-of-the-pack runner Female
Drinking fluids containing no sodium Almond CSD, et al. N Engl J
Med. 2005;352(15): Francesconi RP, et al. J Appl Physiol.
1987;62(3): Maughan RJ, et al. Eur J Appl Physiol Occup Physiol.
1995;71(4): Montain, SJ, et al. Br J Sports Med. 2006;40: Speedy
DB, et al. Med Sci Sports Exerc. 1999;31(6): Vrijens DMJ, et al. J
Appl Physiol. 1999;86: Mechanisms of Hyponatremia During Exercise
Exercise-associated hyponatremia linked to Over drinking of water
Inappropriate arginine vasopressin (AVP) secretion Cytokine
production by damaged muscle Excessive sodium loss
Nonexercise-associated hyponatremia linked to Mental disorders
Post-surgery complications 26 Beltrami FG, et al. Br J Sports Med.
2008;42(10): Francesconi RP, et al. J Appl Physiol. 1987;62(3):
Montain, SJ, et al. Br J Sports Med. 2006;40: Noakes TD, et al. Med
Sci Sports Exerc. 1985;17(3): Rahman M, et al. Neurosurgery.
2009;65(5): Siegel AJ. Harv Rev Psychiatry. 2008;16(1):13-24.
Fluid-Need Estimate for Exercise Weigh yourself a Before exercise
After exercise Record duration of exercise in hours Estimate fluid
volume intake (16 oz = 1 lb) Account for urine loss, if relevant (8
oz = 0.5 lb) BW + drink volume urine volume = Sweat rate, lb/hour
Exercise duration, hour a Method is relevant and precise for 1 to 2
hours of exercise. During longer events, depletion of carbohydrate
may account for some of the change in body weight and is not
associated with fluid loss. 27 American College of Sports Medicine,
et al. Med Sci Sports Exerc. 2007;39(2): Maughan RJ, et al. J
Sports Sci. 2007;25(7): Difference = body weight (BW) in pounds
(lb) Fluid-Need Estimate for Exercise - Metric Weigh yourself a
Before exercise After exercise Record duration of exercise in hours
Estimate fluid volume consumed Account for urine loss, if relevant
Use units of milliliters and divide by 1,000 for Liters BW + drink
volume urine volume = Sweat rate, L/hour Exercise duration, hour a
Method is relevant and precise for 1 to 2 hours of exercise. During
longer events, depletion of carbohydrate may account for some of
the change in body weight and is not associated with fluid loss. 28
Difference = body weight (BW) in kilograms (kg) American College of
Sports Medicine, et al. Med Sci Sports Exerc. 2007;39(2): Maughan
RJ, et al. J Sports Sci. 2007;25(7): Estimating Fluid Intake Needs
During Exercise Repeat procedure for estimating fluid intake in
various weather conditions Calculate estimates for Hot and cooler
days Different amounts of clothing Different intensities of
exercise Apply appropriate sweat rate as part of strategy during
training and competition 29 American College of Sports Medicine, et
al. Med Sci Sports Exerc. 2007;39(2): Strategies to Maintain
Hydration Estimate rate of sweat loss Anticipate volume needs Use
guidelines for replacement 30 American College of Sports Medicine
et al. Med Sci Sports Exerc. 2007;39(2): American Dietetic
Association, et al. Med Sci Sports Exerc. 2009;41: Burke LM, et al.
Sports Med. 1997;24(1): Maughan RJ, et al. Scand J Med Sci Sports.
2010;20(suppl 3):40-47. Fluid Intake Guidelines: US Volumes ACSM
Position Stand Recommended replacement during exercise Volume to
prevent acute loss of >2% of body weight Dont drink in excess No
demonstrable benefits of over hydration Increases risk of
hyponatremia Provides specifics on fluid formulation to optimize
safety and performance Recommended volume to ingest every 15 min to
minimize dehydration Expected sweat rate, lb/hour oz/15 min to
replace 80% oz/15 min to replace 90% oz/15 min to replace 100% a b
lb, pound; oz, ounce. a At this rate, a 121-lb female experiences
only 0.3% dehydration ( 2% of body weight, dehydration can result
in reduced performance and risk of illness Fluid intake needs
should be estimated to replace sweat loss Estimation should
consider temperature, clothing, and exercise conditions Hydration
status should be monitored Strategies to promote safety and
exercise performance under hot conditions Fluid intake containing
appropriate sodium and carbohydrate concentrations Clothing
adjustments Modify exercise session Heat acclimation 40 Appendix 1:
Bibliography Almond CSD, Shin AY, Fortescue EB, et al. Hyponatremia
among runners in the Boston Marathon. N Engl J Med.
2005;352(15):15501556. American College of Sports Medicine, et al.
Position Stand: Exertional Heat Illness During Training and
Competition. Med Sci Sports Exerc. 2007;39(3): American College of
Sports Medicine, et al. Position Stand: Exercise and Fluid
Replacement. Med Sci Sports Exerc. 2007;39(2): American Dietetic
Association, et al. Position Stand: Nutrition and Athletic
Performance. Med Sci Sports Exerc. 2009;41(3): Beltrami FG,
Hew-Butler T, Noakes TD. Drinking policies and exercise-associated
hyponatraemia: is anyone still promoting overdrinking? Br J Sports
Med. 2008;42(10): Brearley MB and Finn JP. Responses of motor-sport
athletes to v8 supercar racing in hot conditions. Int J Sports
Physiol Perform. 2007;2(2): Burke LM, Hawley JA. Fluid balance in
team sports. Guidelines for optimal practices. Sports Med.
1997;24(1): Casa DJ, Armstrong LE, Hillman SK, et al. National
Athletic Trainers Association position statement: fluid replacement
for athletes. J Athl Train. 2010;35(2): Casa DJ, Stearns RL, Lopez
RM, et al. Influence of hydration on physiological function and
performance during trail running in the heat. J Athl Train.
2010;45(2): Cheuvront, SN, Carter R 3rd, Sawka MN. Fluid balance
and endurance exercise performance. Cur Sports Med Rep. 2003;2(4):
Costill DL. Sweating: its composition and effects on body fluids.
Ann NY Acad Sci. 1977;301: Crandell CG and Gonzalez-Alonso J.
Cardiovascular function in the heat-stressed human. Acta Physiol.
2010;199(4): Francesconi RP, Hubbard RW, Szlyk PC, et al. Urinary
and hematological indexes of hydration. J Appl Physiol. 1987;62:
Godek SF, Bartolozzi AR, Peduzzi C, et al. Fluid consumption and
sweating in National Football League and collegiate football
players with different access to fluids during practice. J Athl
Train. 2010;45(2): Gopinathan PM, Pichan G, Sharma VM. Role of
dehydration in heat stress-induced variations in mental
performance. Arch Environ Health. 1988;43(1): Grandjean AC and
Grandjean NR. Dehydration and cognitive performance. J Am Coll
Nutr. 2007;26(5 suppl):549S- 554S. 41 Appendix 1: Bibliography (2)
Greenleaf JE. Problem: thirst, drinking behavior, and involuntary
dehydration. Med Sci Sports Exerc. 1992;24(6): Hunt JN and Knox MT.
The slowing of gastric emptying by four strong acids and three weak
acids. J Physiol. 1972;222(1): Judelson DA, Maresh CM, Anderson JM,
et al. Hydration and muscular performance: does fluid balance
affect strength, power and high-intensity endurance? Sports Med.
2007;37(10): Lieberman HR. Hydration and cognition: a critical
review and recommendations for future research. J Am Coll Nutr.
2007;26(5 suppl):555S-561S. Maughan RJ. Fluid and electrolyte loss
and replacement in exercise. J Sports Sci. 1991;9 Spec No: Maughan
RJ, Dargavel LA, Hares R, Shirreffs SM. Water and salt balance of
well-trained swimmers in training. Int J Sport Nutr Exerc Metab.
2009;19(6): Maughan RJ and Leiper JB. Sodium intake and
post-exercise rehydration in man. Eur J Appl Physiol. 1995;71(4):
Maughan RJ and Shirreffs SM. Dehydration and rehydration in
competitive sport. Scand J Med Sci Sports. 2010;20(suppl 3):
Maughan RJ, Shirreffs SM, Leiper JB. Errors in the estimation of
hydration status from changes in body mass. J Sports Sci.
2007;25(7): Mathews DK, Fox EL, Tanzi D. Physiological responses
during exercise and recovery in a football uniform. J Appl Physiol.
1969;26(5): Montain SJ and Coyle EF. Influence of graded
dehydration on hyperthermia and cardiovascular drift during
exercise. J Appl Physiol. 1992;73(4): Montain SJ, Sawka MN, Wenger
CB. Hyponatremia associated with exercise: risk factors and
pathogenesis. Exerc Sport Sci Rev. 2001;29: Montain, SJ, Cheuvront
SN, Sawka MN. Exercise associated hyponatraemia: quantitative
analysis to understand the aetiology. Br J Sports Med. 2006;40:
Montain SJ, Sawka MN, Latzka WA, et al. Thermal and cardiovascular
strain from hypohydration: influence of exercise intensity. Int J
Sports Med. 1998;19(2): Murray B. Hydration and physical
performance. J Am Coll Nutr. 2007;26(5 suppl):542S-548S. Nadel ER,
Wenger CB, Roberts MF, et al. Physiological defenses against
hyperthermia of exercise. Ann NY Acad Sci. 1977;301: Neville V,
Gant N, Folland JP. Thermoregulatory demands of elite professional
America's Cup yacht racing. Scand J Med Sci Sports. 2010;20(3):
Appendix 1: Bibliography (3) Noakes TD, Goodwin N, Rayner BL, et
al. Water intoxication: a possible complication during endurance
exercise. Med Sci Sports Exerc. 1985;17(3): Palmer MS, Logan HM,
Spriet LL. On-ice sweat rate, voluntary fluid intake, and sodium
balance during practice in male junior ice hockey players drinking
water or a carbohydrate-electrolyte solution. Appl Physiol Nutr
Metab. 2010;35(3): Passe, DH. Physiological and psychological
detriments of fluid intake. In: R. Maughan and R. Murray (eds).
Sports Drinks: Basic Science and Practical Aspects. Boca Raton: CRC
Press; 2000: pp Rahman M and Friedman WA. Hyponatremia in
neurosurgical patients: clinical guidelines development.
Neurosurgery. 2009;65(5): Sato K, Kang WH, Saga K, Sato KT. Biology
of sweat glands and their disorders. I. Normal sweat gland
function. J Am Acad Dermatol. 1989;20(4): Sawka MN, Young AJ,
Francesconi RP, et al. Thermoregulatory and blood responses during
exercise at graded hypohydration levels. J Appl Physiol.
1985;59(5): Sawka MN, Latzka WA, Matott RP, et al. Hydration
effects on temperature regulation. Int J Sports Med.
1998;19(suppl):S108-S110. Shibasaki M and Crandell CG. Mechanisms
and controllers of eccrine sweating in humans. Front Biosci (Schol
Ed). 2011;2: Shirreffs SM and Maughan RJ. Whole body sweat
collection in humans: an improved method with preliminary data on
electrolyte content. J Appl Physiol. 1997;82(1): Shirreffs SM,
Taylor AJ, Leiper JB, et al. Post-exercise rehydration in man:
effects of volume consumed and drink sodium content. Med Sci Sports
Exerc. 1996;28(10): Siegel AJ. Hyponatremia in psychiatric
patients: update on evaluation and management. Harv Rev Psychiatry.
2008;16(1): Speedy DB, Noakes TD, Rogers IR, et al. Hyponatremia in
ultradistance triathletes. Med Sci Sports Exerc. 1999;31(6): Stops
F, Fell JT, Collett JH, et al. The use of citric acid to prolong
the in vivo gastro-retention of a floating dosage form in the
fasted state. Int J Pharm. 2006;308(1-2):8-13. Vrijens DMJ and
Rehrer NJ. Sodium-free fluid ingestion decreases plasma sodium
during exercise in the heat. J Appl Physiol. 1999;86: Wilmore JH,
Costill DL, Kenney WL. Physiology of Sport and Exercise 4th
edition. Champaign: Human Kinetics Publishers; 2008: pp Appendix 2:
Unit Conversions Work or heat: Kilojoules (kj) to kilocalories
(kcal) Multiply kj value by to obtain kcal Temperature: Celsius (C)
to Fahrenheit (F) Multiply the C value by 1.8 and add 32 to obtain
F Concentrations: mmol/L to mEq/L Conversion is one-to-one if
electrolytes are univalent (single charge) Multiply mmol by the
charge on the electrolyte if divalent or greater than one.
Particles to mass: milimoles to milligrams Multiply mmol value by
the atomic weight of the element Metric to English volumes:
milliliters (mL) to ounces (oz) Divide metric volume by 28 ml to
obtain ounces Volume to mass: liters (L) to mass (kg) or oz to
pounds One to one conversion for L to kg (assumes fluid density of
1.00) Divide ounces value by 16 to get pounds (lb) Mass to force:
kilograms (kg) to pounds (lb) Divide kg by 2.2 to obtain weight in
lb 44 Appendix 3: Environmental Awareness and Guidelines A wet
bulb, globe, temperature meter (WBGT) or a sling psychrometer can
be used to monitor environmental conditions 45 Abbreviations: EHS,
exertional heat stroke; F, Fahrenheit. a EHS can still occur due to
other factors. American College of Sports Medicine. Med Sci Sports
Exerc. 2007;39(3): Adapted from Casa DJ, Eichner ER. Exertional
heat illness and hydration. In: Starkey C, Johnson G (eds).
Athletic Training and Sports Medicine. Boston; Jones and Bartlett;
2005: pp
