International Journal of Sport Nutrition and Exercise Metabolism, 2019, 29, 175-180https://doi.org/10.1123/ijsnem.2018-0374© 2019 Human Kinetics, Inc.

SCHOLARLY REVIEW

Fluid Needs for Training, Competition, and Recovery
in Track-and-Field Athletes
Douglas J. Casa
University of Connecticut

Samuel N. Cheuvront
U.S. Army Research Institute of Environmental Medicine

Stuart D. Galloway
University of StirlingSusan M. Shirreffs
University of St. Andrews
The 2019 International Amateur Athletics Federation Track-and-Field World Championships will take place in Qatar in the
Middle East. The 2020 Summer Olympics will take place in Tokyo, Japan. It is quite likely that these events may set the record forhottest competitions in the recorded history of both the Track-and-Field World Championships and Olympic Games. Given theextreme heat in which track-and-ﬁeld athletes will need to train and compete for these games, the importance of hydration is
ampliﬁed more than in previous years. The diverse nature of track-and-ﬁeld events, training programs, and individuality ofathletes taking part inevitably means that ﬂuid needs will be highly variable. Track-and-ﬁeld events can be classiﬁed as low,
moderate, or high risk for dehydration based on typical training and competition scenarios, ﬂuid availability, and anticipatedsweat losses. This paper reviews the risks of dehydration and potential consequences to performance in track-and-ﬁeld events.
The authors also discuss strategies for mitigating the risk of dehydration.
Keywords: athletics, dehydration, hydration, performance, rehydration, running
Seasonal environmental changes can create unique challenges for
year-long training among track-and-ﬁeld athletes. However, thecompetitive track-and-ﬁeld season is held in the summer monthsof the northern hemisphere and major international track-and-ﬁeld
competitions, such as the World Championships and the Olympic
Games culminate in the hottest months of the year. The 2019 IAAF
Track-and-Field World Championships will take place in Qatar in the
Middle East. The 2020 Summer Olympics will take place in Tokyo,
Japan. It is quite likely that these events may set the records for thehottest Track-and-Field World Championships and Olympic Gamesin recorded history. Serious caution is often warranted for hot-weather
Olympic track-and-ﬁeld events (Nielsen, 1996) and the safe preparation and conduct of competitive hot-weather exercise is of greatinternational interest (Racinais et al., 2015). Given the extreme heat inwhich training and competition are likely to take place in Qatar,
Tokyo, and other summer sporting venues of the future, the risks
associated with dehydration could be ampliﬁed more than in previous
years. This review focuses on the risks of dehydration and potential
Casa is with Korey Stringer Institute, Department of Kinesiology, University ofConnecticut, Storrs, CT, USA. Cheuvront is with the U.S. Army Research Instituteof Environmental Medicine, Natick, MA, USA. Galloway is with the Faculty of
Health Sciences and Sport, University of Stirling, Scotland, UK. Shirreffs is with the
University of St Andrews, Scotland, United Kingdom. Casa (douglas.casa@uconn.
edu) is corresponding author.

consequences to performance in track-and-ﬁeld events. We also
discuss strategies for mitigating the risk of dehydration.
The 2003 International Olympic Committee consensus conference concluded the following with regards to hydration in its
consensus statement, which was recently updated in 2011 (IOCConsensus Statement, 2004; IOC Consensus Statement, 2011).
Dehydration impairs performance in most events, and athletesshould be well hydrated before exercise. Sufﬁcient ﬂuid
should be consumed during exercise to limit dehydration toless than about 2% of body mass. . . . Sodium should be
included when sweat losses are high, especially if exercise
lasts more than about 2 h. Athletes should not drink so muchthat they gain weight during exercise. During recovery fromexercise, rehydration should include replacement of bothwater and salts lost in sweat.
Sports nutrition, and sports hydration in particular, is a widely
discussed and sometimes hotly debated topic (Cotter et al., 2014).
However, several recent and comprehensive treatments on the
topics of dehydration, rehydration, and sports performance buttressexisting IOC conclusions (Cheuvront & Keneﬁck, 2014; Evans et al.,2017; McDermott et al., 2017; Savoie et al., 2015; Wittbrodt &Millard-Stafford, 2018). In this review, up-to-date evidence for the
potential impact of dehydration on performance is described andapplied to circumstances and events in track and ﬁeld. Proposed
175

176

Casa et al.

recommendations may be used by athletes and coaches to optimize
performance and health, and by governing organizations when considering the rules and regulations of the sport or the timing of events.

Downloaded by on 04/17/19

Everyday Hydration Assessment
Optimal hydration reﬂects a physical state of having normal body
water and electrolytes, and it is an assumed starting point for mostof the strategies and recommendations reviewed in this paper.
The Venn diagram in Figure 1 is designed to simplify athlete selfassessment of day-to-day hydration status and can help ensure an
optimal starting point for training and competition (Cheuvront &Sawka, 2005). A daily loss of body weight (W) greater than 0.5 to
1.0 kg (1 to 2 lb), a small volume of dark colored urine (U; apple
juice or darker), and the noticeable sensation of thirst (T) are all
symptoms of dehydration. When two or more of these symptoms ofdehydration are present, dehydration is likely. If all three markers
are present, dehydration is very likely. When it is important toaccount for hydration status, all three WUT symptoms should beassessed upon waking each morning. If dehydration is likely or very
likely, greater attention should be given to 24-hr ﬂuid and electrolyte intakes. The use of WUT helps to establish deviations from an
optimal hydration baseline and becomes increasingly importantwhen track-and-ﬁeld athletes travel to locations with warmer
weather or higher terrestrial elevations, both of which can increase
body water losses beyond normal. Travel to locations with limited
potable water availability also requires extra attention to waterplanning and make WUT a useful tool for establishing the adequacyof daily ﬂuid intakes. More advanced hydration assessment techniques are unlikely to be implemented in competition but are
possible in advanced training venues. The interested reader canalso consult Maughan and Shirreffs (2008) for practical hydrationassessment guidance or Armstrong and Casa (2009) for the application of more advanced assessment methods.

Basic Sweat Science
Physical activity requires the use of stored energy to perform work.
In the process, signiﬁcant body heat is generated. Were it not forheat loss mechanisms, a 60-kg runner racing 10 km at 27-minﬁnishing pace would collapse from a lethal body temperature after
only 3.2 km (Dennis & Noakes, 1999; Nielsen, 1996). In weather
that is temperate or warmer, sweating accounts for more than 50%
of body heat removal and close to 100% in very hot environments(Gagge & Gonzalez, 1996). Millions of sweat glands become
activated in response to exercise and the evaporation of sweat
from the skin carries away heat. In fact, the evaporation of 1 L ofsweat from the skin surface can carry away 83% of the heatproduced during a 27-min 10-km race (Wenger, 1972).
The primary factors that inﬂuence total sweat loss (L; Sweating Rate × Time) include body size, exercise intensity, exercise
duration, the environment, and choice of clothing. These factors
explain more than 90% of the widely different sweat losses
expected among athletes (Gagnon et al., 2013). Widely different
factors among different track-and-ﬁeld athletes easily explain why
observed athlete sweating rates can range from 0.5 to 3.0 L/hr
(Baker et al., 2016). Typical ﬂuid needs for adults range from 2 to
4 L/day (Sawka et al., 2005) and function to replace obligatory
losses and dilute metabolic and dietary waste products (Cheuvront& Keneﬁck, 2016). A typical 2-hr/day track-and-ﬁeld training
session could, therefore, increase daily ﬂuid needs by 1 to 6 L/day
due to the range of anticipated sweat losses. Electrolyte losses insweat (sodium and potassium) amount to about 1 g/L (assuming
50 mmol/L) (Baker et al., 2016), which at the low end is replacedby habitual dietary practices, but at the upper end could require
special attention to food electrolyte intakes (Maughan & Shirreffs,
2008). At minimum, track-and-ﬁeld athletes must replace body
water and electrolyte losses daily. Failure to do so can lead todehydration, poor training, and competition outcomes.

Potential Body Water Balance Concerns for Trackand-Field Athletes
Table 1 provides a composite picture of qualitative dehydration riskby track-and-ﬁeld event categories using sweat losses and ﬂuid
availability in training and competition. The table also summarizes
the risk that dehydration, if present or accrued, would negatively
affect performance. The table is meant as a guide for a discussion of
event-speciﬁc risks only. Individual athletes are encouraged topersonalize their ﬂuid intake practices (see “Strategies to Optimize
Hydration” section).

Low-Risk Events

Figure 1 — The Venn diagram for athlete self-assessment of day-to-day
hydration status (Cheuvront & Sawka, 2005). If two or more of the signs(W = reduced body weight, U = dark urine color, and T = feeling thirsty)
are present, then correction of ﬂuid balance is required.

Track-and-Field events with a low-dehydration risk include jumping (with exceptions), throwing, sprints, and multi-events. The
principle reasons for low risk are the types of training performed(e.g., strength, power), the generally unlimited availability of
ﬂuids in both training and competitions, and the small effects thatdehydration has on these types of performance even when present.
Although there are no published data on sweating rates in low-risk
track-and-ﬁeld events, it is anticipated that losses would be lowest
in these events because explosive events like these generate
tremendous heat for only very short periods followed by signiﬁcantrest breaks both in training (between sets) and competition(between rounds). For example, Watson et al. (2005) monitored
sweat volume losses in simulated sprint sessions. In these sessions,the subjects, who were experienced but not elite sprinters, warmed
up for 15 min then ran either a 50- and 200-m sprint separated by
40 min or undertook vertical jumps and a 400-m sprint. Each ofthese sessions was undertaken twice. The body mass reductions

IJSNEM Vol. 29, No. 2, 2019

Fluid Needs for Training, Competition, and Recovery

Table 1

177

Potential Body Water Balance Concerns for Track-and-Field athletes
Sweat lossesa

Event
Jumping (high jump,long jump, triple jump,and pole vault)
Throwing (shot put, javelin,and discus)
Sprints (<800 m)
Middle-distance running(800 m to 10 km)
Long-distancerunning/walking (>10 km)
Multievents (decathlon)

Training

Competition

Availability of fluids
Training

Competition

Risk of dehydration
Training

Competition

Performance risk
Training

Competition

b

Mod

Low

High

High

Low

Low

Low

Low

Mod

Low

High

High

Low

Low

Low

Low

Mod
High

Low
Low

High
Mod

High
Low

Low
Mod

Low
Low

Low
Mod

Low
High

High

High

Low

Low

High

High

High

High

High

Mod

High

High

Low

Low

Low

Low

Downloaded by on 04/17/19

Note. Mod = moderate.
a
Product of sweating rate and time. bAssumes no purposeful dehydration.

averaged 0.8 and 1.3 kg in the 50/200-m sessions over a 2-hr
period, and averaged 0.5 and 1.1 kg over 45 min in the 400 m andvertical jump session. These reductions are equivalent to approximately 1–1.5% of the athletes’ body mass and easily replaceable
during the training session.
Jumping performance has frequently been investigated as ameans of assessing the inﬂuence of a body water loss on muscle
power: jump power and jump height have been most frequently
measured (Cheuvront et al., 2010; Gutiérrez et al., 2003; Hoffman
et al.,1995; Kraemer et al., 2001; Viitasalo at al., 1987; Watson et al.,2005). In theory, intentional dehydration might be desired to try andimprove jumping performance by virtue of being “lighter.” In fact, if
dehydration did not impair muscle force production in any way, thenjump height improvements should reﬂect the level of dehydration(i.e., 1% dehydration should improve jump height by 1%) (seeappendix in Cheuvront et al., 2010). The majority of studies
investigating the effects of dehydration on jump performance
have used between 1% and 4% dehydration (Cheuvront et al.,2010; Gutiérrez et al., 2003; Hoffman et al., 1995; Watson et al.,2005) although a 6% body mass loss has been investigated whenenergy restriction has been combined with dehydration (Kraemer
et al., 2001; Viitasalo et al., 1987). Yet the majority of these studies
have found no signiﬁcant effect of the body mass reduction on
jumping power or height. When Cheuvront et al. (2010) replaced thewater lost as weight worn ergonomically as a vest, jump performance decreased when dehydrated. This suggests that the beneﬁts ofbeing lighter when dehydrated are masked by the detrimental effects
of dehydration on muscle function. When the effects are combined,
there are no “measurable” effects on performance.
The conclusion that dehydration impairs some aspect(s) ofstrength or power is cautionary for throwing events, which rely
heavily on strength and power. Indeed, two systematic reviews andone meta-analysis summarizing the effects of dehydration on
muscle strength, power, and high-intensity anaerobic capacity(Cheuvront & Keneﬁck, 2014; Judelson et al., 2007; Savoie
et al., 2015) determined that dehydration can impair strengthand power. However, it was concluded that a signiﬁcant loss ofbody water (3–4% body mass) was required to produce small, but
signiﬁcant effects on performance. Although small effects remainof utmost importance in elite sports (Hopkins et al., 1999), the riskof achieving 3–4% dehydration in sprinting, jumping, and throwing events is very low. Therefore, the risks to performance are also
low (Table 1). As a result, the main concern for hydration in low-risk track-and-ﬁeld events is to ensure that training and competition
are begun in a state of optimal hydration. This is especially true formulti-event track-and-ﬁeld athletes who may be competing formany hours, but with ample opportunities for rest and rehydration.

Moderate-Risk Events
The middle distances for running (800 m to 3 km) and some longdistance running events (5–10 km) may be considered track-andﬁeld events with moderate risk for dehydration. Although the riskof dehydration is low in the events themselves due to their shortdurations (< 2 to < 30 min), moderate risk for these events stems
from daily high and sustained sweat losses which could carry overto negatively affect training and performance from day-to-day.
Fluid availability may also be high (e.g., track training) or low(road training), depending on the training season or phase of
training. Moderate risk middle and long-distance running eventsin track and ﬁeld are all contested entirely on a track. Therefore, as
for the sprints, the duration of the races are short enough to preclude
ﬂuid being taken during the events and too short for signiﬁcantdehydration to develop during the race, even when sweating rates
are very high. As with low-risk events, the main concern forhydration in low-risk track-and-ﬁeld events is to ensure thattraining and competition are begun in a state of optimal hydration.
However, given the endurance and interval training frequently
undertaken by these athletes, the volumes of sweat that may be lost
and the likelihood that drinking during training may frequently belimited for logistical or stomach comfort reasons, dehydration
during training for many middle and long distance runners may
be a common scenario. Deliberate rehydration strategies (see“Basic Rehydration Science” section) may become necessary
when a signiﬁcant portion of the training has yet to take place,particularly when the desire is to complete a high-quality training
session with a “performance” element to it. The negative effects ofdehydration on the energy system relied upon for competitive
middle and long-distance running is discussed below.

High-Risk Events
Long-distance running and walking events (20–50 km) may beconsidered track-and-ﬁeld events with a high risk for dehydration.
In comparison to the other track-and-ﬁeld events, there has been a
considerable amount of both descriptive research into sweat losses

IJSNEM Vol. 29, No. 2, 2019

Downloaded by on 04/17/19

178

Casa et al.

of runners during at least some of the long-distance events (inparticular, the marathon) and also intervention studies investigating
the effects of dehydration on endurance exercise performance.
Training involves many hours of running and walking where ﬂuid
availability/support must be planned in advance. During competitions, ﬂuid availability is minimal and the intensity of exercise may
make it difﬁcult to prevent progressive dehydration from occurring,particularly late in a competition when high levels of performanceare required. Indeed, dehydration to levels well beyond those
associated with impaired performance (>2% of body mass) has
been consistently reported at the ﬁnish of marathon races(Cheuvront & Haymes, 2001).
The effects of dehydration on endurance running or walking
performance must be viewed through the lens of both laboratory andﬁeld studies of endurance “exercise.” The mode of test activity is often
not running or walking and the caliber of athlete tested is rarely elite.
However, research outcomes are interpreted using the same aerobic
energy system, and the knowledge that human performance responses
to stressors such as environmental heat vary only by degree whencomparing elite and recreational runners (Ely et al., 2008) or whencomparing laboratory outcomes to ﬁeld observations (Casa et al.,2010), which permits reasonable extrapolation of results.
Cheuvront and Keneﬁck (2014) reviewed 34 studies conducted
between 1961 and 2012 investigating the effects of dehydration on
endurance exercise performance. Of the 60 total performance observations, 41 (68%) showed a statistically signiﬁcantly impairment
in performance when dehydrated and 12 more (88%) reported an
overall group decrement in performance that did not reach statisticalsigniﬁcance. These ﬁndings are more impressive still when one
considers that most studies are undertaken with the minimal numberof test volunteers necessary to ﬁnd statistical signiﬁcance. Cheuvront
and Keneﬁck (2014) concluded that dehydration ≥2% of body mass
impairs endurance exercise performance as measured primarily by ashortened time to exhaustion or reduction in sustainable exercise
intensity. Importantly, the effect is magniﬁed in warmer environmental temperatures (Keneﬁck et al., 2010). In addition, partial
rehydration has been shown to dramatically enhance performanceand physiological function during running in the heat, and the effectis exacerbated if the exercise is intense (Casa et al., 2010; Lopez et al.,2016). Whether programmed or thirst-driven drinking strategies are
more successful depends highly on the circumstances of the training
and competition (Keneﬁck, 2018). A more detailed discussion of this
topic follows (see “Strategies for Optimizing Hydration” section). So
long as dehydration is limited to <2% of body mass, performance islikely to be sustainable in all track-and-ﬁeld events.

Dehydration and Mental Readiness
The potential effects of dehydration on brain function could impact
track-and-ﬁeld athlete performance by interfering with one or more
aspects of concentration or motivation. It is widely and consistently
reported that dehydration has a negative effect on mood statethrough one or more alterations in perceived tiredness, alertness,
confusion, fatigue, anger, or depression (Cheuvront & Keneﬁck,
2014). When dehydration is ≥2% body mass, it can also produce
unpleasant and distractive symptoms, such as dry mouth, thirst, andheadache (Cheuvront & Keneﬁck, 2014).
A meta-analysis by Wittbrodt and Millard-Stafford (2018)
examined the impact of dehydration on cognitive performancefrom 33 studies that included more than 400 test subjects. Widevariability was observed among studies, but the authors concluded
that dehydration ≥ 2% body mass produced a small, but statisticallysigniﬁcant impairment in cognitive performance tasks involving
attention, executive function, and motor coordination (Wittbrodt &Millard-Stafford, 2018). As ≥2% dehydration appears to describe
both physical and mental performance thresholds, it is likely thatthe risks to attention, executive function, and motor coordination
are primarily for high-risk track-and-ﬁeld events that rely little on
the mental performance measures affected.

Basic Rehydration Science
Sweat is composed primarily of water (∼99.9%). Although sweat
electrolyte losses can require special attention to dietary replacement (see “Basic Sweat Science” section), most ﬂuids are consumed with meals and most meals generally provide ample
replacement of sweat electrolytes, particularly when energy consumption matches energy utilization. However, when ﬂavor isdesired, timing between meals is uncertain or extended, or training/competition is anticipated to be intense and prolonged, a typicalsports drink formulation can provide energy (4–6% carbohydrate),
contribute to the replacement of the electrolytes lost in sweat(20 mmol/L sodium; 4 mmol/L potassium), and generally beabsorbed faster than water alone (Baker & Jeukendrup, 2014;
Leiper, 2015). For all track-and-ﬁeld athletes, optimal rehydration
may best be sustained between training days by behaviorallydriven ingestion of solid food and water (Maughan et al., 1996).
However, between training sessions or events, beverages that
contain macronutrients or electrolytes are better retained than waterand should be considered (Maughan et al., 2016, 2018; Shirreffs
et al., 1996; Sollanek et al., 2018).

Strategies for Optimizing Hydration
It is clear that for all track-and-ﬁeld events, optimal day-to-day
hydration is most important for optimizing training and competition. The concepts reviewed in Figure 1 are a simple but effective
starting point for success. Other simple (Maughan & Shirreffs,
2008) and more advanced techniques (Armstrong & Casa, 2009)
may also be adopted. For low- and moderate-risk track-and-ﬁeld
events, the daily use of Figure 1 and the use of thirst to guidedrinking behavior is probably sufﬁcient for optimizing hydration—
particularly when training and competing in familiar settings andwhen there is no limit to food or ﬂuid access (Keneﬁck, 2018). But
when training or competing in high-risk events—particularly whenin unfamiliar settings or when access to food and ﬂuid may belimited, then a more programmed approach centered aroundknowledge of personal sweat losses is recommended (Cheuvront& Keneﬁck, 2017; Keneﬁck, 2018).
Track-and-Field athletes train as they intend to compete; ﬂuid
replacement planning should be part of the strategy. For example, in a
marathon race, drink stations are positioned at regular intervals. The
absence of water stations during long training runs means implementing a drinking strategy by other means, such as with wearable drink
systems. A simple strategy such as this can accustom gastric tolerance
and optimize hydration for the most difﬁcult training sessions. It
appears that while >90% of IAAF athletes have a ﬂuid intake plan
when competitions are forecasted to be hot, the volumes planned may
or may not reﬂect anticipated losses (Périard et al., 2017).
The ﬂip side of replacing sweat losses is to minimize sweat
losses so that less drinking is needed. Various kinds of thermal
management scenarios are possible, such as cold towels, ice vests,
indoor (air conditioned) exercise, and early morning- or lateevening exercise. Ingestion of ice slurry before exercise is an

IJSNEM Vol. 29, No. 2, 2019

Fluid Needs for Training, Competition, and Recovery

Table 2

179

Practical Strategies to Reduce Dehydration for Track-and-Field Athletes

Strategy

Details

WUT

First morning weight, urine color, and thirst sensation to guide day-to-day adequacy of water and electrolyte
consumption.
Rehydrate with meals and include sodium and potassium-rich foods.
Estimate personal sweat losses from changes in body weight pre- to postexercise.
Incorporate a competition drinking strategy into training (e.g., using wearable drinking systems as a
substitute for water stations).
Train during the coolest times of daya; consider indoor air-conditioned training in extreme heat; and consider useof active cooling (e.g., cold towels, cold showers).

Incorporate electrolytes
Personalize ﬂuid needs
Train as you compete
Improve thermal management

Note. W = reduced body weight; U = dark urine color; T = feeling thirsty. aExcept when deliberate heat acclimatization is desired.

alternative hydration strategy, but appears no more effective thancold water and may produce untoward side effects (Jay & Morris,2018). The practice of trying to delay dehydration by expanding total
body water using beverages with high salt concentrations or glycerol
is generally ineffective and carries its own risks (McDermott et al.,2017). Approximately 50% of IAAF athletes practice some form of
thermal management before hot weather competitions (Périard et al.,2017). Table 2 summarizes strategies for optimizing hydration.

Downloaded by on 04/17/19

Summary
The impact of dehydration on training and performance outcomesin athletes remains a much-debated topic. Track-and-ﬁeld athletes
often train and compete in hot environmental conditions, where
ﬂuid balance and hydration become essential daily considerations.
Given the individual nature of sweating responses with training andcompetition, each athlete should assess their own individual ﬂuid
requirements and determine if these are likely to be a cause forconcern (e.g., if >2% body mass loss observed). The risk of
impairment in training or performance with levels of dehydrationof <2% body mass loss is “low” and applies to many track-and-ﬁeld
events (particularly sprints, jumps, and throws). However, otherTrack and Field events carry a “high” risk, typically in the longer
duration and continuous activities, such as endurance events. For
these events, careful attention should be placed on individualized
and planned hydration practices to optimize training and performance outcomes.
Acknowledgments
The authors would like to offer our sincerest gratitude to Robert Carter,
who was an author on the original manuscript. In addition, they are gratefulfor the assistance of Yasuki Sekiguchi, a doctoral student at the Universityof Connecticut in the USA for his assistance with some technical aspects ofthis publication. The opinions or assertions contained herein are the private
views of the authors and should not be construed as ofﬁcial or reﬂecting theviews of the Army or the Department of Defense. Approved for public
release: distribution unlimited.

References
Armstrong, L.E., & Casa, D.J. (2009). Methods to evaluate electrolyte andwater turnover of athletes. Athletic Training and Sports Health Care,
1(4), 169–179. doi:10.3928/19425864-20090625-06
Baker, L.B., Barnes, K.A., Anderson, M.L., Passe, D.H., & Stofan, J.R.
(2016). Normative data for regional sweat sodium concentration andwhole-body sweating rate in athletes. Journal of Sports Sciences, 34(4),358–368. PubMed ID: 26070030 doi:10.1080/02640414.2015.1055291

Baker, L.B., & Jeukendrup, A.E. (2014). Optimal composition of ﬂuidreplacement beverages. Comprehensive Physiology, 4(2), 575–620.
PubMed ID: 24715561 doi:10.1002/cphy.c130014
Casa, D.J., Stearns, R.L., Lopez, R.M., Ganio, M.S., McDermott, B.P.,
Walker Yeargin, S., : : : Maresh, C.M. (2010). Inﬂuence of hydration
on physiological function and performance during trail running in theheat. Journal of Athletic Training, 45(2), 147–156. PubMed ID:
20210618 doi:10.4085/1062-6050-45.2.147
Cheuvront, S.N., & Haymes, E.M. (2001). Thermoregulation and marathon running: biological and environmental inﬂuences. Sports Medicine, 31(10), 743–762. doi:10.2165/00007256-200131100-00004
Cheuvront, S.N., & Keneﬁck, R.W. (2014). Dehydration: Physiology,
assessment, and performance effects. Comprehensive Physiology,
4(1), 257–285. PubMed ID: 24692140 doi:10.1002/cphy.c130017
Cheuvront, S.N., & Keneﬁck, R.W. (2016). Am I drinking enough? Yes, no,and maybe. Journal of the American College of Nutrition, 35(2), 185–
192. PubMed ID: 26885571 doi:10.1080/07315724.2015.1067872
Cheuvront, S.N., & Keneﬁck, R.W. (2017). CORP: Improving the statusquo for measuring whole body sweat losses. Journal of Applied
Physiology, 123(3), 632–636. doi:10.1152/japplphysiol.00433.
2017
Cheuvront, S.N., Keneﬁck, R.W., Ely, B.R., Harman, E.A., Castellani,
J.W., Frykman, P.N., : : : Sawka, M.N. (2010). Hypohydration
reduces vertical ground reaction impulse but not jump height.
European Journal of Applied Physiology, 109(6), 1163–1170.
PubMed ID: 20379829 doi:10.1007/s00421-010-1458-y
Cheuvront, S.N., & Sawka, M.N. (2005). Hydration assessment of
athletes. Gatorade Sports Science Institute, 18(2), 1–5.
Cotter, J.D., Thornton, S.N., Lee, J.K., & Laursen, P.B. (2014). Are webeing drowned in hydration advice? Thirsty for more? Extreme
Physiology & Medicine, 3(1), 18. PubMed ID: 25356197 doi:10.
1186/2046-7648-3-18
Dennis, S.C., & Noakes, T.D. (1999). Advantages of a smaller bodymass
in humans when distance-running in warm, humid conditions.
European Journal of Applied Physiology and Occupational Physiology, 79(3), 280–284. PubMed ID: PubMed ID: 10048634
Ely, M.R., Martin, D.E., Cheuvront, S.N., & Montain, S.J. (2008). Effectof ambient temperature on marathon pacing is dependent on runnerability. Medicine & Science in Sports & Exercise, 40(9), 1675–1680.
doi:10.1249/MSS.0b013e3181788da9
Evans, G.H., James, L.J., Shirreffs, S.M., & Maughan, R.J. (2017).
Optimizing the restoration and maintenance of ﬂuid balance after
exercise-induced dehydration. Journal of Applied Physiology,
122(4), 945–951. doi:10.1152/japplphysiol.00745.2016
Gagge, A.P., & Gonzalez, R.R. (1996). Mechanisms of heat exchange:
Biophysics and physiology. In: M.J. Fregly & C.M. Blatteis (Eds.),
Handbook of physiology: Environmental physiology (pp. 45–84).
Bethesda, MD: American Physiological Society.

IJSNEM Vol. 29, No. 2, 2019

Downloaded by on 04/17/19

180

Casa et al.

Gagnon, D., Jay, O., & Kenny, G.P. (2013). The evaporative requirement
for heat balance determines whole-body sweat rate during exercise
under conditions permitting full evaporation. The Journal of Physiology, 591(11), 2925–2935. PubMed ID: 23459754 doi:10.1113/
jphysiol.2012.248823
Gutiérrez, A., Mesa, J.L.M., Ruiz, J.R., Chirosa, L.J., & Castillo, M.J.
(2003). Sauna-induced rapid weight loss decreases explosive power
in women but not in men. International Journal of Sports Medicine,24(7), 518–522. doi:10.1055/s-2003-42017
Hoffman, J.R., Stavsky, H., & Falk, B. (1995). The effect of water
restriction on anaerobic power and vertical jumping height inbasketball players. International Journal of Sports Medicine,
16(4), 214–218. PubMed ID: 7657413 doi:10.1055/s-2007-972994
Hopkins, W.G., Hawley, J.A., & Burke, L.M. (1999). Design and analysisof research on sport performance enhancement. Medicine & Sciencein Sports & Exercise, 31(3), 472–485. doi:10.1097/00005768199903000-00018
IOC consensus statement on sports nutrition 2003. (2004). Journal ofSports Sciences, 22(1).
IOC consensus statement on sports nutrition 2010. (2011). Journal of Sports
Sciences, 29(Suppl. 1), S3–S4. doi:10.1080/02640414.2011.619349
Jay, O., & Morris, N.B. (2018). Does cold water or ice slurry ingestion
during exercise elicit a net body cooling effect in the heat? Sports
Medicine, 48(Suppl. 1), 17–29. doi:10.1007/s40279-017-0842-8
Judelson, D.A., Maresh, C.M., Anderson, J.M., Armstrong, L.E., Casa,
D.J., Kraemer, W.J., & Volek, J.S. (2007). Hydration and muscularperformance: Does ﬂuid balance affect strength, power and highintensity endurance? Sports Medicine, 37(10), 907–921. doi:10.2165/
00007256-200737100-00006
Keneﬁck, R.W. (2018). Drinking strategies: Planned drinking versus
drinking to thirst. Sports Medicine, 48(Suppl. 1), 31–37. doi:10.
1007/s40279-017-0844-6
Keneﬁck, R.W., Cheuvront, S.N., Palombo, L.J., Ely, B.R., & Sawka,
M.N. (2010). Skin temperature modiﬁes the impact of hypohydration
on aerobic performance. Journal of Applied Physiology, 109(1),79–86. doi:10.1152/japplphysiol.00135.2010
Kraemer, W.J., Fry, A.C., Rubin, M.R., Triplett-McBride, T., Gordon,
S.E., Koziris, L.P., : : : Fleck, S.J. (2001). Physiological and performance responses to tournament wrestling. Medicine & Sciencein Sports & Exercise, 33(8), 1367–1378. doi:10.1097/00005768200108000-00019
Leiper, J.B. (2015). Fate of ingested ﬂuids: Factors affecting gastric
emptying and intestinal absorption of beverages in humans. Nutrition
Reviews, 73(Suppl. 2), 57–72. doi:10.1093/nutrit/nuv032
Lopez, R.M., Casa, D.J., Jensen, K.A., Stearns, R.L., DeMartini, J.K.,
Pagnotta, K.D., : : : Maresh, C.M. (2016). Comparison of two ﬂuid
replacement protocols during a 20-km trail running race in the heat.
Journal of Strength & Conditioning Research, 30(9), 2609–2616.
doi:10.1519/JSC.0000000000001359
Maughan, R.J., Leiper, J.B., & Shirreffs, S.M. (1996). Restoration of ﬂuid
balance after exercise-induced dehydration: effects of food and ﬂuid
intake. European Journal of Applied Physiology and Occupational
Physiology, 73(3–4), 317–325. PubMed ID: 8861691 doi:10.1007/
BF02425493
Maughan, R.J., & Shirreffs, S.M. (2008). Development of individual
hydration strategies for athletes. International Journal of Sport
Nutrition and Exercise Metabolism, 18(5), 457–472. PubMed ID:
PubMed ID: 19033609 doi:10.1123/ijsnem.18.5.457
Maughan, R.J., Watson, P., Cordery, P.A., Walsh, N.P., Oliver, S.J., Dolci,A., : : : Galloway, S.D. (2016). A randomized trial to assess thepotential of different beverages to affect hydration status: Development of a beverage hydration index. The American Journal of
Clinical Nutrition, 103(3), 717–723. PubMed ID: 26702122
doi:10.3945/ajcn.115.114769
Maughan, R.J., Watson, P., Cordery, P.A., Walsh, N.P., Oliver, S.J., Dolci,A., : : : Galloway, S.D. (2018). Sucrose and sodium but not caffeine
content inﬂuence the retention of beverages in humans under euhydrated conditions. International Journal of Sport Nutrition andExercise Metabolism,29(12), 51–60. doi:10.1123/ijsnem.2018-0047
McDermott, B.P., Anderson, S.A., Armstrong, L.E., Casa, D.J.,
Cheuvront, S.N., Cooper, L., : : : Roberts, W.O. (2017). National
Athletic Trainers’ Association position statement: Fluid replacement
for the physically active. Journal of Athletic Training, 52(9),877–895. PubMed ID: 28985128 doi:10.4085/1062-6050-52.9.02
Nielsen, B. (1996). Olympics in Atlanta: A ﬁght against physics. Medicine& Science in Sports & Exercise, 28(6), 665–668. doi:10.1097/
00005768-199606000-00004
Périard, J.D., Racinais, S., Timpka, T., Dahlström, Ö., Spreco, A.,
Jacobsson, J., : : : Alonso, J.-M. (2017). Strategies and factors
associated with preparing for competing in the heat: A cohort study
at the 2015 IAAF World Athletics Championships. British Journal ofSports Medicine, 51(4), 264–270. PubMed ID: 27815238 doi:10.
1136/bjsports-2016-096579
Racinais, S., Alonso, J.M., Coutts, A.J., Flouris, A.D., Girard, O.,
González-Alonso, J., : : : Périard, J.D. (2015). Consensus recommendations on training and competing in the heat. British Journal ofSports Medicine, 49(18), 1164–1173. PubMed ID: 26069301 doi:10.
1136/bjsports-2015-094915
Savoie, F.-A., Keneﬁck, R.W., Ely, B.R., Cheuvront, S.N., & Goulet,
E.D.B. (2015). Effect of hypohydration on muscle endurance,
strength, anaerobic power and capacity and vertical jumping ability:
A meta-analysis. Sports Medicine, 45(8), 1207–1227. doi:10.1007/
s40279-015-0349-010.1007/s40279-015-0349-0
Sawka, M.N., Cheuvront, S.N., & Carter, R. (2005). Human water needs.
Nutrition Reviews, 63(6 Pt 2), S30–S39. PubMed ID: 16028570
doi:10.1111/j.1753-4887.2005.tb00152.x
Shirreffs, S.M., Taylor, A.J., Leiper, J.B., & Maughan, R.J. (1996). Postexercise rehydration in man: effects of volume consumed and drink
sodium content. Medicine & Science in Sports & Exercise, 28(10),1260–1271. doi:10.1097/00005768-199610000-00009
Sollanek, K.J., Tsurumoto, M., Vidyasagar, S., Keneﬁck, R.W., &Cheuvront, S.N. (2018). Neither body mass nor sex inﬂuences beverage
hydration index outcomes during randomized trial when comparing 3
commercial beverages. The American Journal of Clinical Nutrition,
107(4), 544–549. PubMed ID: 29635499 doi:10.1093/ajcn/nqy005
Viitasalo, J.T., Kyröläinen, H., Bosco, C., & Alen, M. (1987). Effects of
rapid weight reduction on force production and vertical jumping
height. International Journal of Sports Medicine, 8(4), 281–285.
PubMed ID: 3667026 doi:10.1055/s-2008-1025670
Watson, G., Judelson, D.A., Armstrong, L.E., Yeargin, S.W., Casa, D.J., &Maresh, C.M. (2005). Inﬂuence of diuretic-induced dehydration oncompetitive sprint and power performance. Medicine & Science inSports & Exercise, 37(7), 1168–1174. doi:10.1249/01.mss.
0000170100.93279.beWenger, C.B. (1972). Heat of evaporation of sweat: Thermodynamic
considerations. Journal of Applied Physiology, 32(4), 456–459.
PubMed ID: 5026491 doi:10.1152/jappl.1972.32.4.456
Wittbrodt, M.T., & Millard-Stafford, M. (2018). Dehydration impairs cognitive performance: A meta-analysis. Medicine & Science in Sports &Exercise,50(11), 2360–2368. doi:10.1249/MSS.0000000000001682

IJSNEM Vol. 29, No. 2, 2019