THE EFFECTS OF A PRE-COOLING ICE SLURRY ON REPEATED SPRINT ABILITY IN
RECREATIONALLY ACTIVE MALES

By

Henry A. Castejon-Gutierrez, B.S.
East Stroudsburg University of Pennsylvania

A Thesis submitted in Partial Fulfillment of
the Requirements for the Degree of Master of Science in Exercise Science
to the office of Graduate and Extended Studies of
East Stroudsburg University of Pennsylvania

August 6, 2021

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ABSTRACT
A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master
of Science in Exercise Science to the office of Graduate and Extended Studies of East
Stroudsburg University of Pennsylvania
Students Name: Henry A. Castejon – Gutierrez, B.S.
Title: The effects of a pre-cooling ice slurry on repeat sprint ability in recreationally
active males
Date of Graduation: August 6, 2021
Thesis Chair: Matthew Miltenberger, Ph.D.
Thesis Member: Shala Davis, Ph.D.
Thesis Member: Shawn Munford, Ph.D.
Abstract
The ability to produce consistently high average sprint time over a series of sprints
separated by less than or equal to 60 seconds of recovery is vital for sports. Muscle and
core temperature is a major contributor to fatigue. Precooling has shown to be and
effective means of lower the body’s core temperature. Purpose: The aim of this study
was to look at the effect of an ice slurry beverage in a precooling protocol on peak sprint
time, mean sprint time, RPE and fatigue index during a repeated sprint protocol (5 x
40m shuttle sprints with 30s of passive recovery). Fifteen healthy recreationally active
°college aged 18- 24 males. A precooling protocol of 7.5g/kg of bodyweight either water
or ice slurry administered over a 30 minute period in ten minute intervals. Following the
precooling protocol subjects completed a 5x40m sprint protocol with 30s of passive
recovery. RPE, core temperature and sprint time were all recorded after every sprint.
There was no significant difference in sprint times (p= 0.750), RPE (p = 0.588) and core
temperature (p = 0.908). There was a significant difference in pre- cooling core
temperature between conditions (p = 0.02). Precooling protocol consisting of an ice
slurry approximately 1°C was effective at lowering core temperature vs control
condition. This did not yield any significant difference in sprint time, RPE or core
temperature during the sprint protocol. Additional research is needed to exhibit the
benefits of precooling during repeated sprints.

TABLE OF CONTENTS
LIST OF TABLES………………………………………………………………………………………………………………vi
LIST OF CHARTS…………………………………………………………………………………………………………….vii

CHAPTER
I.

INTRODUCTION……………………………………………………………………………………..…….1
Purpose………………………………………………………………………………………………………..6
Null Hypothesis…………………………………………………………………………………………….6
Limitations…………………………………………………………………………………………..….……7
Delimitations…………………………………………………………………………………………..……7
Operational Definitions…………………………………………………………………………………7

II.

LITERATURE REVIEW…………………………………………………………………………………….8
Repeated sprint ability in sport……………………………………………………………………..9
Mechanisms of fatigue…………………………………………………..……………………………10
Ambient temperature…………………………………………………………………………………12
Aerobic Fitness……………………………………………………………………………………………13
Movement Efficiency………………………………………………………………………………….13
Airflow………………………………………………………………………………………………………..15
Pre – cooling……………………………………………………………………………………………….15

III.

METHODOLOGY………………………………………………………….………………………………19
Subjects………………………………………………………………………………………………………19

iv

Protocol Overview………………………………………………………………………………………20
Protocol Procedure………………………………………………………………………………..…..21
Familiarization trials……………………………………………………………………….…………..22
Experimental trials…………………………………………..…………………………..…………….23
Statistical Analysis……………………………………………………..……………………………….25
IV.

RESULTS………………………………………………………………………………….………………….26
Descriptive analysis ………………………………………………………………….………………..26
Ambient temperature…………………………………………………………………………………28
Baseline precooling results………………………………………………………………………….29
Sprint protocol results…………………………………………………………………………………31

V.

DISCUSSION, FUTURE RECCOMENDATIONS & CONCLUSION……………………..40
Precooling protocol…………………………………………………………………………..………..40
Exercise protocol…………………………………………………………………………………………42
Ambient temperature…………………………………………………………………………………42
Fatigue……………………………………………………………………………………………..………..43
Practical application……………………………………………………………………………………44
Future recommendations……………………………………………………………………………45
Conclusion………………………………………………………………………………………………….46

APPENDICES…………………………………………………………………………………………….…………………..48
REFERENCES…………………………………………………………………………………………………………………53

v

LIST OF TABLES
Table
1. Characteristics of the study participants…………………………………………………..………20
2. Baseline core temperature measurements……………………………………………………….27
3. Mean sprint time results…………………………………………………………………………..………28
4. Peak sprint time results…………………………………………………………………………………….28
5. Rate of perceived exertion results…………………………………………………………………….28
6. Ambient temperature results……………………………………………………………………………29
7. Mean baseline precooling core temperature values for all conditions………………30
8. Baseline precooling core temperature ANOVA results………………………………………30
9. Mean values for all conditions of all subjects per a variable………….………………….32
10. Sprint core temperature ANOVA results……………………………………………………………32
11. Sprint time ANOVA results……………………………………………………………………..…………33
12. Rate of perceived exertion ANOVA results………………………………………………………..33
13. Peak and mean sprint time results……………………………………………………………………37
14. Peak sprint time (percent decrement)………………………………………………………………38

vi

LIST OF FIGURES
Figure
1. Session overview………………………………………………………………………………………………21
2. Precooling protocol overview……………………………………………………………………………24
3. Sprint protocol overview…………………………………………………………………………………..24
4. Mean baseline core temperature by condition…………………………………………………31
5. Mean sprint core temperature by condition………………………………..……………………34
6. Mean sprint time by condition………………………………………………………………………….34
7. Mean rate of perceived exertion by condition………………………………………………….35
8. Mean core temperature by sprint bout…………………………………………………………….35
9. Mean RPE by sprint bout………………………………………………………………………..…………36

vii

CHAPTER 1
Introduction
Sprint durations lasting less than or equal to ten seconds and brief periods of
recovery are common in most team sports. The ability to produce consistently high
average sprint time over a series of sprints separated by less than or equal to 60
seconds of recovery is vital for sports such as soccer. This has been termed as repeatedsprint ability (Girard et al 2015). Although sprint type activities only account for
approximately 10% of the total distance covered in a game (C. Carling et al.,2011),
improving repeated sprint ability should result in the improvement of physical
performance in team sports like soccer (Bishop, D. J et al 2011). According to Mohr
(Mohr et al, 2003) players on average perform 150 to 250 brief bouts of high intensity
activity during a game. These brief bouts occur during crucial moments of the game for
example chasing another player or scoring a goal. Players who can maintain a relatively
high sprint speed throughout many bouts are more likely to perform better for an
extended period of time. Motion analysis data has shown not only decrease of distance
covered in the latter half of the game but also a decrease in mean speed at which the

1

athletes moves. The amount of decline is also determined by the skill level of the athlete
(C. Carling et al. 2011). This indicates an accumulation of fatigue during the later half of
the game (stolen et al., 2005). According to Carling (C. Carling et al.,2011) bouts of high
intensity in soccer games are usually paired with an active recovery period lasting less
than 21 seconds of jogging or walking.
Understanding the specific movement patterns of a sport and the duration of
work to rest periods allows for an understanding of the contributions of the energy
systems. Oxidative phosphorylation contributes only less than 10% to total energy
expenditure during a short sprint. When sprints are repeated the level of contribution
from aerobic metabolism may increase to as much as 40% of the total energy supply
during the final repetitions of repeated sprint training (Girard, O et al., 2011). Repeated
sprint activities are associated with short duration sprints and short recovery periods.
During a short bout of exercise there will be heavy dependence on phosphocreatine
(PCr) degradation. In the period of rest following the bout there will be resynthesis in
PCr. However, during the short rest intervals of repeated-sprint training there will be an
incomplete resynthesis in PCr. This causes the increase in contribution from aerobic
metabolism (Moir, G. L. 2015).
During repeated sprint activities fatigue is recognized by the decrease in peak
power and decrease in mean or maximal sprint speed over a period of several sprints

(Girard, O.2011). Muscle and core temperature have a noticeable effect on exercise and
sport performance. Temperature of muscle and core can have different effects
depending on the mode and duration of the exercise. Elevated muscle temperature
2

enhances sprint performance after an active or passive warmup (Drust et al, 2005).
Rising of muscle temperature can increase single sprint performance by possibly
increasing PCr utilization during prolonged submaximal exercise. However, there will be
an accumulation of lactate, elevation of the muscle temperature and core body
temperature. An elevation in core body temperature may lead to increase in central
nervous system fatigue and cardiovascular strain causing a decline sprint speed even
after the first bout (D. Wendt et al 2007).
Many team- sports require sustained exercise performance in mid to high
ambient temperatures during training and competition. Exercising or performing under
high ambient temperatures or continuous sustained exercise results in a noted increase
in core (T core) and skin (T skin) temperatures. As temperature rises, the metabolic and
cardiovascular load increases and quickens neuromuscular fatigue (R. Duffield, 2007). It
has been proposed that there is a critical body temperature that triggers voluntary
fatigue in subjects regardless of different starting temperatures and the athlete’s ability
to regulate heat (D. Wendt, 2007).
Cooling methods have been not only utilized in high ambient temperature
environments but also in thermo-neutral environments. During prolonged exercise the
increase of body temperature is proportional to the rise of metabolic rate and demand
of exercise. Regardless of heat acclimation or training state of the athlete, there is a
common absolute heat storage limit. Given that there is a limit in heat storage capacity
it would be advantageous to begin exercise at the lowest body temperature possible (F.
E. Marino, 2002). A common method of cooling frequently investigated to improve sport
3

performance is pre-cooling. Pre-cooling is used by many athletes and coaches to reduce
body temperature prior to exercise by decreasing the onset of heat stress to improve
performance (Siegel, R et al.,2012).
There are several common protocols of pre-cooling such as cooling packs and
vests, cold room or air cooled, water application or cold water immersion and cold
drinks. Regardless of the method the time prior to exercise and the length of time it
takes to complete the protocol and achieve sufficient body cooling seems to be the
most important factors. Factors like practicality of the protocol prior to an event or
practice become more important when selecting a protocol (F. E. Marino, 2002).
Cooling packs and vests are easy to use on the field and are convenient for the
athlete but also have potential disadvantages. Many vests and packs are not tailored for
the specific athlete and may not offer proper heat transfer. Discomfort from the size
and weight of the vest must also be considered and the cold temperature of the vest
may cause thermal discomfort to the athlete. Ice vest and packs mainly cause a
decrease in skin temperature (T skin ) which leads to skin vasoconstriction.
Vasoconstriction reduces blood flow to the skin thus reducing the exchange of heat
between the athlete and the cooling vest or pack. A proper cooling level or power will
need to be established to produce the best result (N. Bogerd, 2010).
Cold air exposure is among the least practical protocols for field use as studies
using this method indicate that cooling body temperature on average ranges from 40 to
130 minutes prior to exercise. This time can include a rewarming period to reduce
thermal discomfort and shivering (F. E. Marino et al., 2002). Although cold air exposure
4

has demonstrated to have a beneficial effect on performance, application of this
protocol would be difficult in a sport setting being as time and proper facilities are
required for this method to be effective.
According to Wegmann (M. Wegmann et al., 2012) cold water or air applications
has been shown to have the lowest percentage of improvement when compared to
other protocols of pre-cooling. According to Siegel (Siegel et al., 2012) ice slurry
ingestion did yield a higher core temperature of (0.28 ˚C) more compared to cold water
or air. Ice slurry ingestion does not cause a significant decrease in skin or muscle
temperature. An increase in skin and muscle temperature followed by a warm up and a
decrease in starting core temperature prior to exercise allows for a theoretical
maintenance of repeat-sprint performance after ingesting an ice slurry. Not requiring
special equipment or facilities, ice slurry ingestion is the most practical means of precooling (F.E Marino et al 2002)
Different methods of pre-cooling have been used to mitigate the effects of heat
related fatigue. According to Wegmann (M. Wegmann et al., 2012), ice slurry yielded
the highest percentage of improvement (15% relative). However, these effects were
obtained in environments with high ambient temperatures or on a cycle ergometer.
Limited studies have examined the relationship between repeated-sprint (running)
ability and precooling in non-acclimatized athletes in thermo-neutral temperature (>
23˚C). No substantial effects on performance has been observed on heat acclimated
athletes from precooling (Brade, C. J et al 2013). However, few studies have assessed

5

the effects of pre-cooling methods such as ice slurry and water in a thermo-neutral
ambient temperature on repeated sprint (running) performance.

Purpose
The purpose of this study was to investigate the effects of a precooling ice slurry
on repeat sprint performance on non- acclimatized individuals. in a thermo-neutral
indoor environment. The following variables were be collected for analysis mean sprint
time, peak sprint time, and fatigue was measured using percent decrement.
Additionally, physiological variables such as, rating of perceived exertion, and core
temperature were also measured.

Null Hypothesis
There will be no statistically significant difference between the control, tepid
water, and ice slurry for baseline core temperature.
There will be no statistically significant differences between the control, tepid
water, and ice slurry for mean sprint time.
There will be no statistically significant differences between the control, tepid
water and ice slurry for peak sprint time.
There will be no statistically significant differences between the control, tepid
water and ice slurry for sprint core temperature.
There will be no statistically significant differences between the control, tepid
water and ice slurry for rating of perceived exertion.
6

Limitations
1. The participants in the study dietary and exercise regimen were not
regulated.
2. There is a possibility that the participants did not complete the sprint bouts
with maximum effort.
3. Participants could have possibly paced themselves throughout the whole
trial.

Delimitations
1. Participants in the study were 18- 24 years’ old.
2. Participants were free of musculoskeletal injuries and / or surgeries 6 months
prior and were all recreationally active.
3. All participants were students of East Stroudsburg University.
Operational Definitions
Pre- cooling – method of reducing body temperature before exercise.
Thermo - neutral temperature - (16- 23˚C)
Repeated Sprint- Short duration sprints of <10 seconds with interspersed
recovery periods of (<60 seconds)
Ice Slurry- a beverage containing a mixture of ice, water.
Tepid Water – A mixture of cold and hot water rendering a temperature of 37 –
39˚C .

7

CHAPTER II
Literature Review
The purpose of this chapter is to highlight all of the important background data
related to pre-cooling and repeat sprint ability. Specifically this chapter will focus on
repeated sprint ability, mechanisms of fatigue, temperature, pre-cooling.

Regardless of the type of sport directly or indirectly, the ability to produce
maximal short term effort is vital in many competitive sports (O. Girard et al., 2015). The
ability to produce high average sprint performance over a series of sprints less than 10
seconds with less than or equal to 60 seconds of recovery has been termed repeated
sprint ability (RSA). Most competitive sports require completion of these tasks during
warm to hot ambient temperatures (25-45 ºC) (Duffield et al. 2007). Exercising in
environments like these leads to an increase in the body core’s temperature, potentially
decreasing performance (Wegmann et al. 2012). This is usually exhibited by a decreased
time to exhaustion and or longer time – trial completion time (O. Girard et al., 2015).
When an athlete’s core temperature is cooled prior to exercise or competition the
performance decrement is counteracted (Bogerd et al. 2010). Pre- cooling is a method
8

of reducing pre – exercise skin and or core body temperature (Duffield et al. 2007).
There are several proposed mechanisms as to how precooling reduces heat stress and
delays thermally induced fatigue. Many studies have shown beneficial effects of precooling with a meta-analysis (Wegmann et al. 2012) finding a 4.9% increase on average
in performance in the studies analyzed. Studies have shown a large effect in endurance
based exercise and also to intermittent and repeated-sprint exercise to a smaller
degree. Several authors have demonstrated a large reduction of peak and mean sprint
power output in the heat leading to the increase in core temperature causing a decrease
in performance (Girard et al., 2011), ( Drust, Bishop et al., 2005)

Repeated sprint ability in sport
Repeated sprint ability is characterized as short duration sprints (less than ten
seconds) interspersed with recovery periods of less than sixty seconds. The ability to
recover and produce consistent sprint performance is an important fitness requirement
for field team sports (Girard et al 2015). Repeated sprint ability is important in team
sports but protocols and tests must accurately depict real in game movement patterns
(C.Carling et al., 2012). Match analysis of soccer players has demonstrated varying
movement patterns, speeds, sprint bout, recovery times and mode of recovery between
them for the different positions played and level of skill (C. Carling et al 2012). On average
players perform 150 – 250 bouts of high intensity activity less than ten seconds long
(Mohr et al, 2003). Recovery between these bouts consisted of primarily walking. It is
thought that repeated sprint ability can determine the final outcome of the game by
9

influencing the ability to win possession of the ball or concede goals (Girard et al). Studies
by Mohr et al, (2003) have shown that even when skill level is accounted for, high intensity
activity decreases significantly during the second half of a soccer game suggesting a
development of fatigue throughout the game.
Repeated sprint ability is measured using a variety of different testing methods
and systems like shuttle runs, sprints, bikes and treadmills (Glaister et al., 2008).
According to Shalfawi (Shalfawi, S. A. I. et al., 2012) most running repeated sprint
measurements are done using photocell timing gates. The Brower Speed Trap II running
speed timing system is among the most well documented in the literature (e.g. Caldwell
& Peters, 2009; Coh, Milanovic, & Kampmiller, 2001; Ebben, 2008; Ebben, et al., 2008;
Wisloff, et al., 2004). According to Shalfawi (Shalfawi, S.A. I. et al., 2012) the Brower
Speed Trap II running timing system has been determined to be reliable measure of
running sprint speed.

Mechanisms of Fatigue
Fatigue during repeated-sprint activity is characterized by a decrease in sprint
time between bouts in a single session or a decrease in peak/mean power output
(Bishop et al 2011). There are many contributing factors to fatigue during repeated
sprint exercises such as phosphocreatine resynthesis (PCr) and H+ accumulation to
fatigue from heat strain. A brief recovery time associated with repeated sprint exercises
only allows a partial restoration of PCr which may be a determinant of sprint
performance (B. Dawson et al.,1997). Repeated sprint performance may be improved by
10

training protocols that increase rate of PCr degradation. Training methods such as 6 x 12
second bouts of sprint training with 60 second rest intervals have shown an
improvement in the rate of rephosphorylation (D. Bishop et al.,2008). PCr is an
important fatigue factor in repeated sprint ability during protocols with shorter rest
intervals. During protocols with rest intervals of less than sixty seconds there is an
incomplete resynthesis of PCr and more reliance in anaerobic glycolysis which explains a
high accumulation lactate (TheBault N. et al).
The initial contribution of PCr is high during repeated sprint exercise but as rest
intervals decrease and the number of bouts increases per a session there is an increase
reliance in anaerobic glycolysis leading to the buildup of lactate (TheBault N. et al). In a
previous study (Spencer et al, 2008) there was significant increase in lactate
accumulation in the active recovery group study compared to the passive recovery
group. The mode of recovery according to Mohr (Mohr et al, 2003) is typically active in
nature consisting of walking or a light jogging during in game. Fatigue from lactate
accumulation is associated with increase in acidosis from H+ in blood and muscle
leading to the decrease in ATP from anaerobic glycolysis (Bishop et al, 2011).
The exact mechanism of fatigue caused by heat isn’t exactly known. A possible
cause of fatigue is caused by high muscle temperature. This may alter or damage
structural proteins disrupting electrolyte distribution and mitochondrial respiration. It
was also found that increase core temperature for a long duration increases central
nervous system fatigue. This is caused by the increase in inhibitory signals by the
hypothalamus. This alteration in muscle structure may also affect cardiac muscles and
11

can influence the contractility of these muscles reducing stroke volume. This decrease in
stroke volume results in ultimately a decrease in cardiac output. Another possible
contributor to the decrease in stroke volume is the change in blood volume delivered
back to the heart. The increase in core temperature had a direct correlation with the
increase in heart rate (Gonzalez- Alonso et al 1999). The increase in heart rate and
intern decrease in stroke volume may be caused by the decrease filling time during
diastolic filling. It was discussed by( Nybo et al 2008) that an actual increase in
performance can occur from a temporary increase in temperature in outer limbs. Stroke
volume decreases by the increase in exercise volume, body position and heat stress.
With the increase in heat stress, there is more blood perfusion towards the skin. During
these conditions stroke volume is severely affected increasing fatigue accumilation.

Ambient Temperature
Core temperature has a noticeable effect on exercise and sport performance (B.
Drust). Stress from heat is typically associated with a decreased time to exhaustion or
longer completion of a time trial (O. Girard et al). Heat from skeletal muscle triggers
major physiological mechanisms to dissipate heat to the skin and then to the outside
environment. During exercise this process reverses, and heat transfers from muscle to
blood and ultimately to the core. There are several mechanisms by which heat can be
gained or loss: metabolism, radiation, conduction, convection and evaporation. Heat
regulation and transfer is determined by a temperature gradient. During exercise sweat
glands secrete sweat to the skin’s surface. This promotes heat loss by evaporating the
12

water content from the sweat. The environment has a large effect on the rate of sweat
loss and evaporation. In an environment with a temperature greater than or equal to
36º C the body gains heat by radiation and convection during rest. (Wendt et al. 2007).

Aerobic Fitness
Aerobic fitness has also been a determinant of thermoregulatory capacity (Hayes
et al. 2014). Benefits acquired from aerobic fitness yield positive results for
thermoregulation. Body composition plays a major role in heat production and
thermoregulation. Athletes with a leaner body composition store more water by virtue
of their lean body mass and low fat content. This increased muscle mass also coincides
with increase glycogen stores and the water associated (Mora- Rodriguez et al 2012).
Surface to mass ratio is another factor. This refers to the ratio of total skin surface area
and total mass in an individual. Total mass acts like a “sink” to store heat during
exercise. More body mass entails more stored body heat (Havinth et al 1998). Sweat is
the primary mode of thermoregulation during exercise (Wendt et al. 2007). A smaller
skin to mass ration means the rate of heat dissipation may be more difficult with higher
mass but less skin surface area.

Movement Efficiency
Efficiency of a movement increases with prolonged training. Efficiency of running
is defined by running economy This is primarily caused by fiber type adaptations.
Trained athletes have a higher density of type 1 fibers compared to a non-trained
13

athletes which are more metabolically efficient than type II fibers. It has been found that
aerobically fit individuals experience greater core body temperature changes during
high intensity bouts of exercise (smolijanic et al 2014) compared to unfit groups when
matched for body morphology. During moderate intensity the effect is inverted favoring
aerobically fit athletes and sweat response is often delayed during the onset of exercise.
During moderate continuous exercise sweat response is often delayed longer for
untrained than trained individuals. This is usually caused by the lower plasma volume
found in untrained individuals. This has little effect on excessive heat accumilation and
does not hinder heat equilibrium of dissipation and accumilation. Although during high
intensity bouts coupled with short resting periods heat may accumulate and fatigue may
accrue rapidly (Mora-Rodriguez et al 2012). Gait pattern of running differs greatly from
walking. During human bipedal walking there is a constant alternation between
potential and kinetic energy. Walking is done by vaulting over still limbs and turning
gravitational potential energy into forward kinetic energy. During running limbs are
primarily used as springs used to store and return muscular elastic energy. Muscles in
the limbs conserve elastic energy, meaning the primary consumption of muscles during
locomotion is the support of the individuals body mass. It can be deduced that the force
used to support body mass is the primary determinant of metabolic cost of running
(Farley et al 1992).

14

Airflow
Convection is another important factor of thermoregulation. Proper air flow is
required to allow the sweat to evaporate properly into the surrounding environment
(Mora- Rodriguez et al 2012). One study concluded that without proper airflow
rehydration had nearly no effect on core temperature. This leads to a concern for
individuals exercising indoors (Mora- Rodriguez et al 2007). It is even suggested that
airflow may reduce thermal strain even in hypo hydrated individuals (Cheuvront et al
2004). Rehydration is effective only coupled with proper airflow in the exercise
environment (Mora- Rodriguez et al 2007). Sweating is vital for cooling by means of
evaporation. If airflow at minimum does not resemble outside conditions, sweat drips
rather than evaporates resulting in no heat loss and heat accruing rapidly. At relative
exercise intensities higher trained individuals train at an absolute higher workload than
untrained individuals. Trained individuals for example may run at a faster pace and may
experience more airflow. This is known as the differential air flow effect and should be
considered in future studies (Mora- Rodriguez et al 2012).

Pre- cooling
Pre- cooling is a common method used by many athletes. The purpose of precooling is to reduce the body temperature prior to exercise or competition. This will
reduce heat stress and improve athletic performance (Wegmann et al. 2012). Heat from
the environment or generated by the athlete causes increased core and skin
temperature causing increased cardio-vascular and metabolic loads in addition to
15

neuromuscular and endurance fatigue (Duffield et al). There are several effective
methods of pre – cooling such as ice vests, ice packs, water immersion, air- cooling or
cold drinks (Siegel et al). Selecting the most optimal pre- cooling method depends
heavily on the circumstances of the ambient temperature, protocol, type of sport and
many other factors (Wegmann et al., 2012).
Ice vests are among the most researched methods of pre-cooling. They have
been found to be effective most with a mixed method. Typically paired with ice slurry
ingestion approach with several cooling sites on the body (O. Girard et al., 2015).
According to Marino (F.E Marino et al., 2002) ice vest cooling has been shown to reduce
physiological and psychophysical pain and improve endurance performance on a cycle
ergometer. In addition, Duffield (Duffield et al., 2003) has found a decrease in
perception of participant’s thermal load. Ice vest or cooling jackets require ample time
to prepare and cool athlete, prior to the event. Making it difficult to use them practically
prior to an athletic event (Ross et al., 2013).
In addition to Ice jackets, water immersion is another common method of
precooling. Marino (F.E. Marino et al., 2002) proposes a gradual decrease in water
temperature during water immersion to ensure no physical discomfort. It is for this
reason that water immersion precooling methods are the longest duration. Second only
to air cooling in duration, water immersion is not a very practical means of precooling
prior to an event or game (Wendt et al.,2007). Even with this disadvantage water
immersion does have some significant advantageous. According to Wegmann
(Wegmann et al.,2012) water immersion methods lead to rapid and large reductions of
16

body core temperature. Another advantage is the rate of heat loss to water is two or
four times greater than to air at the same temperature. This allows the skin to remain
generally around water temperature creating a more uniform skin temperature (F.E.
Marino et al., 2002). This rapid and large decrease in both core and skin temperature
allows for a more positive perception of effort possibly enhancing willingness to
maintain maximal effort sprints. Water immersion has been shown to improve
subjective perception of recovery during a 5 x 40m repeated sprint protocol (Cook,
Beaven, 2013). A possible factor in this is the common drop of core temperature after
the precooling phase and before the onset of exercise (F.E. Marino et al.,2002).
Although this method of precooling is effective, practicality and deciding on duration
and temperature of water are always variables to consider when deciding a whole body
precooling method (Wegmann et al.,2012).
Air cooling is a method that has been shown to greatly improve endurance based
sport and training (Wegmann et al., 2012). Air cooling like water immersion also causes
drop in core temperature after the precooling phase prior to the onset of exercise (F.E.
Marino et al., 2002). Although air cooling has some similar advantages as water
immersion with Wegmann (Wegmann et al., 2012) finding a 10.7% effect size being
second only to cold drinks which had a 15% effect size. Air cooling is a far less practical
means of cooling, requiring steady environmental conditions in an enclosed
environment.
Variables like cost and time are major factors preventing practical use prior to an
event or practice. Ice Slurry beverages seems to be the most practical means of
17

precooling. Ingestion of an ice slurry does not have a direct cooling effect on the
musculature unlike other precooling interventions and has major positive effects on
performance similar to water immersion (Siegel et al.,2012). According to the results
from Beaven (Beaven et al.,2018) ice slurries alone caused a minor decrease in initial
sprint speed but increased fatigue resistance in a 5x 40m repeated sprint protocol. Ice
slurry precooling method offers high practicality, convenience and a low time - to effect.

18

Chapter III
Methodology
Subjects
This study was approved by the Institutional Review Board of East Stroudsburg
University. Participation was voluntary and each participant underwent an orientation
with written informed consent. The purpose of this study was to investigate the effect
of an ice slurry precooling protocol on peak sprint time, mean sprint time, RPE , core
temperature and fatigue index during a repeated sprint protocol (5 x 40m shuttle sprints
with 30s of passive recovery). Thirteen healthy recreationally active college aged 18- 25
males volunteered to take part in the study. Table 1 below represents the
characteristics of the participants (n = 13).

19

Table 1

Protocol Overview
The repeated-sprint protocol was adapted and utilized by Impellizzeri et al. The
participants attended a total of four sessions : (1) Orientation, consent form and
familiarization protocol , (2-4) Randomized trials consisting of either Control, Water, Ice
slurry. Control trial consisted of no consumption of any beverage. A Water trial
consisting of consumption 7.5g/kg of mass of tepid water at approximately 37 degrees
Celsius. The final trial consisting of the consumption of an ice slurry 7.5g/kg of mass. All
subjects were required to complete all sessions in a randomized order with at least 3
days interspersed between trials. During each session excluding the first session all
subjects were required to wear athletic clothing and were asked to either refrain from
exercise for the past 24 hours prior to the session and had to be 3 hours post
absorptive. Height and weight were all collected and recorded. During sessions (2-4)
subjects were asked to be 3 hours post absorptive. Participants either refrain from
consuming any beverage, water (7.5g per a kg of body mass) or slurry (7.5g per a kg of
body mass) during the first 30 min of the session. Core temperature was measured
using a tympanic thermometer every 10 minutes during the pre-cooling period. After 30
min precooling period subjects warmed up and began the repeated sprint protocol of 5
20

x 40m shuttle sprints with 30s of passive recovery between each sprint. RPE and Core
temperature were measured after every sprint. Peak and mean sprint time were
recorded and power output and percent decrement score were calculated. Trials were
completed with a minimum of 3 days in-between sessions.

Session 1

Session 2-4

•Orientation
•Consent
•Familiarization trial

Control (no beverage)
Water beverage
Slushy beverage

Figure 1. Session Overview
Protocol Procedures
Session 1 participants reviewed and signed an informed consent document.
Subjects were also informed on the purpose of the study and all procedures. Subjects
were allowed to ask questions about any requirements that they were required to do. A
Physical Activities Readiness Questionnaire (PAR- Q) was filled out by subjects to ensure
that they did not have any prior conditions preventing them from participating. If any
participants answered “yes” to any questions on page one, the subject was not allowed
to participate. Subjects were also given written instructions for the following sessions
which included procedures and requirements of the patient for remaining sessions.
Subjects were asked to abstain from vigorous activity and caffeine 24 hours prior. All
subjects were 3 hours post absorptive prior to every session. Demographic data of the
subjects were collected which included age (years), height (cm) and body mass (kg).

21

Familiarization Trial
Session 1 also consisted of the familiarization trial. Participants were allowed to
ask questions at any point during the trial to ensure complete understanding of the
protocol. Participants were asked to complete a short dynamic warm up. The warm up
consisted of a minimum of two lap jog totaling of 400 meters around an indoor track,
this was coupled with short dynamic warm up assigned by the tester. The warm up
consisted of various assigned warmup exercises such as lunges, leg swings, knee hugs,
back pedaling, side shuffling and karaoke. Subjects were also allowed to do their own
exercises. Those exercises had to be repeated for every subsequent trial. Following the
warmup subjects began a trial of 3 maximum sprints. Measurements were required for
the following trials to assure that subjects completed the sprints at a time of at least
90% of their maximum sprint time. If times were not met participants were asked to
attend the session at the following week to ensure no pacing strategy. Timing gates
were setup 40 meters apart with cones indicating to the subject how far. Subjects were
instructed to be one meter from the starting timing gate and initiated protocol on three
second countdown. Subjects had 30 seconds of passive recovery in between every 40meter sprint. Rate of Perceived Exertion (RPE) and core temperature were recorded
after every sprint. RPE was measured using the RPE (6-20) Borg Scale and core
temperature was measured using an ear thermometer.

22

Experimental Trials
Sessions (2-4 ) consisted of experimental trials. All subjects were randomized and
counterbalanced when assigned to a testing group in a specific order. Subjects arrived at
the same time as their familiarization trial on the day of testing. Participants were asked
to not engage in strenuous exercise prior to trials, to wear proper attire and to be 3
hours post absorptive. Once arriving to the lab participants were given a beverage or
not according to a random protocol they were assigned. Participants were given 7.5g of
water or ice slurry per a kg of body mass or nothing to consume during the 30-minute
pre-cooling phase. They were also asked to remain seated and relaxed during entire precooling phase. Core temperature was measured and recorded every 10 minutes during
this phase. Following this phase the participants began their warm up of a minimum of
two laps around an indoor track totaling 400 meters and the tester assigned a dynamic
warm up. Warm up consisted of various assigned warmup exercises lunges, leg swings,
knee hugs, back pedaling, side shuffling and karaoke. Participants were also allowed to
do their own exercises. All exercises and routines that were used from the
familiarization trial were repeated for experimental trials. Core temperature was then
measured post warm up. The participants began the protocol one meter from the first
timing gate with a three second countdown to begin the first sprint. Subjects began the
protocol of 5 x 40m sprints that was used during the familiarization trial. Subjects were
given 30 seconds of passive recovery in-between sprint bouts. During recovery time RPE
was measured using the (6-20) Borg Scale and core temperature was measured using an
ear thermometer.
23

Lab Arrival

Measurement 2

0-10 minutes

20- 30 minutes
10- 20 minutes

Measurement 1

Measurement 3

Figure 2. Precooling Protocol Overview

1
2
3
4
5
6

• Subject begins consumption of beverage
• Measure core temperature every 10 minutes during 30 minute pre- cooling
period
• Subject begins warm up

• Core temperature measured post- warm up
• Subject begins protocol, 1 meter from first timing gate
• Begin 3 second countdown
• Core Temperature and RPE measured after every sprint bout

Figure 3. Sprint Protocol Overview
The inclusion criteria for this study consists of at least being recreationally active
defined as participating in less than or equal to twice a week of aerobic activity for a
24

total of 80 minutes at a moderate intensity. Participants were also free of any metabolic
or heat related illnesses. Participants were also free of lower limb injuries within 6
months.

Statistical Analysis
Statistical analysis was performed using SSPS Version 24 for windows (SPSS.,
Chicago, IL). The means and standard deviation was calculated for all variables that were
recorded during testing. A univariate analysis of variance (ANOVA) was used to
determine a significant difference in baseline core temperature and sprint time. A two
way ANOVA was done for sprint core temperature and RPE. A Bonferroni post hoc
analysis was done for precooling temperature, sprint core temperature, RPE and sprint
time to determine which conditions had a significant differences from another.
Statistical significance was determined using a p-value of p < 0.05.

25

Chapter IV
Results
The primary purpose of this study was to investigate the effects of precooling
(Ice slurry, water) on a repeated sprint running protocol: 5 x 40m on non-acclimatized
individuals in thermo-neutral indoor conditions. This chapter presents data on the
following: Mean baseline core temperature, mean sprint time, peak sprint time, sprint
core temperature, sprint RPE, fatigue (% decrement).
Descriptive Analysis
The initial two – way ANOVA results for baseline precooling temperature was
used to determine whether or not there was a significant difference in precooling
temperature between any of the conditions. Table 2 below reveals the mean (SD) and
change in temperature for each condition during the baseline precooling protocol. The
mean and standard deviation for control, water and Ice Slurry w 36.68 ± 0.34, 36.62 ±
0.24 and 36.35 ± 0.29 respectively. There was a significant difference in baseline
precooling core temperature between the control and ice slurry precooling protocol.
Table 3 below shows the mean sprint time for each sprint for each condition. The threeway ANOVA did not reveal any significant difference in any mean sprint times for any
26

condition. The mean sprint time for control , water and ice slurry were 5.83 ± 0.53, 5.77
± 0.49 and 5.78 ± 0.44 seconds respectively. Table 4 below shows the peak sprint time
average for all participants by condition. Peak sprint time like mean sprint time did not
differ much among each subject. Peak sprint time was measured by choosing the fastest
time for each subject. The mean peak sprint time for control was 5.69 ± 0.48, 5.66 ±
0.48 and 5.69 ± 0.44. Table 5 below shows the mean Rate of Perceived Exertion of all
the participants for each condition. Rate of Perceived Exertion was recorded using the
Borg’s scale 6 – 20. The mean RPE for control, water and ice slurry 11.79 ± 3.18, 11.69 ±
3.33 and 11.32 ± 2.90. The three – way ANOVA did not find any significant difference
between any condition. Although there wasn’t a significant difference between RPE,
there was a slight correlation showing the ice slurry condition being the lowest recorded
RPE out of all the conditions.

Table 2

Note * = Significant difference in temperature in Control compared to Ice slurry. p < 0.05

27

Table 3

Table 4

Table 5

Ambient Temperature
Ambient temperature was measured using a weather station. All measurements
were taken prior to the sprint protocol. All ambient temperature measurements are
displayed below on table 6. Temperature measurements were consistent throughout all
the repeated sprint protocols. Water had the highest average recorded humidity at
28

61.69% while the lowest average recorded humidity was Ice which was 50.54%
humidity. All ambient temperatures were generally the same. There was some variation
in humidity but not a noticeable difference with generally most trials measuring the
same.

Table 6

Baseline Precooling Results
Baseline core temperature was measured every 10 minutes during the
precooling protocol. Precooling protocol was a control condition, water condition which
only consisted of tepid water and ice slurry condition consisting of an ice slurry
containing only water and ice. Table 7 below displays the means of all subjects baseline
core temperature by time interval and total baseline core temperature across all
conditions. The baseline core temperature for control condition was 36.68± 0.34 ˚C. The
mean baseline core temperature for water condition was 36.62± 0.24˚C. In contrast the
ice condition had an average 36.35± 0.29 ˚C. Only one core temperature measurement
was recorded for the control condition during the precooling protocol. Water condition
shows a slight decrease in temperature over time whereas ice shows a significant
decrease over time. The ice slurry precooling protocol resulted in a significant

29

difference between the control condition and the ice slurry condition. The results of a
the three way ANOVA displayed in Table 8 showed a significant difference in baseline
core temperature (P= 0.021; f = 4.287). This significant difference between control and
ice condition can be displayed below on Figure 4.

Table 7

Table 8

30

37.2

Temperature ( Co )

37
36.8
36.6
36.4
36.2
36
Control

Water

Ice

Figure 4. Mean baseline core temperature by condition

Sprint Protocol Results
There was no significant difference in sprint core temperature between any
condition during the sprint protocol (p = 0.908;f = 0.097) which is displayed below on
table 10. The mean sprint core temperature for control was 36.27 ± 0.44℃. The mean
sprint core temperature for water was 36.25 ± 0.33℃. The mean sprint core
temperature for ice slurry condition was 36.24 ± 0.37℃. Figure 5 below displays the
mean sprint core temperature for each condition. Mean sprint core temperature was
virtually the same across all conditions.
The ANOVA results for sprint time displayed below on table 7 showed no
significant difference in sprint time between any condition (p = 0.750;f = .288). The
mean sprint time for control was 5.83 ± 0.53s. The mean sprint time for water was 5.76
± 0.47s. The mean sprint time for the ice condition was 5.79 ± 0.43s. Figure 6 below
displays the mean sprint times by conditions. There was no significant difference in RPE
31

between any condition (p = 0.588;f = 0.533) which is displayed below on Table 11. The
mean RPE for control was 11.8 ± 3.2. The mean RPE for water was 11.7 ± 3.3. The mean
RPE for Ice slurry was 11.3 ± 2.9. Figure 7 below displays all the mean RPE values of all
subject by condition. The averages in Table 9 are post-dose (post precooling
consumption) and were measured after every sprint bout. The measurements in Table 9
are averages of all the variables measured by condition. Like stated previously there
was no significant difference between any of these variable among all conditions. There
was a slight correlation found with RPE. Ice slurry condition had the lowest RPE value
compared to control and water condition.
Table 9

Table 10

32

Table 11

Table 12.

33

36.8
36.7
Temperature ( C0 )

36.6
36.5
36.4
36.3
36.2
36.1
36
35.9
35.8
Control

Water

Ice

Time (s)

Figure 5. Mean Sprint core temperature by condition

6.5
6.4
6.3
6.2
6.1
6
5.9
5.8
5.7
5.6
5.5
5.4
5.3
5.2
Control

Water

Figure 6. Mean Sprint time by condition

34

Ice

15.5
15
14.5
14

RPE

13.5
13
12.5
12
11.5
11
10.5
10
Control

Water

Ice

Figure 7. Mean Rate of Perceived Exertion by condition

Core Temperaturre (℃)

36.45
36.4
36.35
36.3
36.25
36.2
36.15
36.1
1

2

3

4

Sprint bout
Control

Water

Figure 8. Mean core temperature by sprint bout

35

Ice

5

Figure 8 displays the mean core temperature of all the subjects for each sprint
bout of all condition. Water both had the highest average core temperature (36.39 ±
0.24) for the first sprint, and the lowest recorded 5th sprint temperature of (36.17 ±
0.37). Ice condition had the lowest starting temperature (36.27 ± 0.39), but did not have
the lowest recorded temperature for the last sprint (36.25 ± 0.44). Control condition
had an average first sprint core temperature of (36.35 ± 0.49), control condition also
had the highest 5th and final sprint core temperature of (36.28 ± 0.44).

Rate of percieved exertion (RPE)

15
14
13
12
11
10
9
8
7
6
1

2

3

4

Sprint bout
Control

Water

Figure 9. Mean RPE by sprint bout

36

Ice

5

Figure 9 shows the average RPE of all subjects for each sprint bout of all
condition. Control had both the highest RPE average for both the first and last sprint of
(9.1 ± 2.36, 14.5 ± 2.86). Water had an average RPE of (8.8 ± 2.42) for the first sprint and
an average of (13.5 ± 2.93) for the final sprint. Ice condition did have the lowest
recorded RPE for the first and last sprint (8.7 ± 1.49, 13.3 ± 2.93).

Table 13

37

Table 14

Table 13 above shows the mean peak and mean sprint time for each subject.
Several participants listed in table 13 increased in speed over time during the trial. This
explains the close values between peak and mean sprint time. Table 14 shows the peak
with percent decrement. The change in the time showed on table 14 indicates either an
increase or decrease in sprint time. Subject 5 showed the greatest change in sprint time
for the control condition. Subject 3 and 10 showed the greatest change for the water
condition. Subject 5 again showed the greatest change in sprint time during the ice
condition and was among six other subjects which experienced a progressive decrease
in sprint time during the 5 sprint bouts. Subject 9 experienced the smallest change in
time during the control condition. Subject 6 had the lowest change in sprint time during
38

the water condition and subject 1 had the lowest change in sprint time during the ice
condition.
Percent Decrement = (100 × (total sprint time ÷ ideal sprint time)) − 100
where Total sprint time = Sum of sprint times from all sprints.
Ideal sprint time = The number of sprints × fastest sprint time. (Glaister et al 2008)

39

Chapter V
Discussion and Conclusion
The purpose of this study was to investigate the effect of an ice slurry precooling
protocol on peak sprint time, mean sprint time, RPE, core temperature and fatigue (%
decrement) during a repeated sprint protocol (5 x 40m shuttle sprints with 30s of
passive recovery). Thirteen healthy recreationally active college aged 18- 24 males
volunteered to take part in the study.

Precooling Protocol
The main finding of this investigation was a significant difference in core
temperature (P=0.021) between control and ice condition during the pre-cooling
protocol. Repeated sprint performance saw no significant differences between control
and ice conditions. There were also no significant differences between any condition for
core temperature and RPE. Similar results were found in (Brade et al 2013) which also
found a significant decrease in core temperature but also found no difference in sprint
performance. The pre-cooling protocol for this study was ingestion of an ice- slurry for a
total of 30 minutes in 10 minute increments with core temperature being measured
40

every increment. Several studies have found ice slurry in combination with a
cooling vest such as (brade et al 2014) significantly improved performance. Studies like
this consisted of exercise protocols with total exercise duration lasting up to 30 to 40
minutes. Average exercise core temperatures for all conditions were virtually the same
(36.2 °C) with minor variations (Control 36.27°C, Water 36. 25°C, Ice 36.24°C). A
possible conclusion from this data is the precooling protocol was effective for only a
short duration. Precooling with an ice slurry in conjunction with a cooling vest has been
found to be effective with inclusion of cooling during the exercise protocol (Brade et al
2014, Bogerd et al 2013). The longer duration of low core temperature can possibly be
attributed to the cooling during the exercise protocol maintaining the low core
temperature throughout the protocol (Bogerd et al 2013). Ice slurry method has been
found to be highly effective at dropping core temperature very rapidly compared to
methods such as the ice vest or cold water immersion but without the reduction in skin
temperature. This causes a rapid rise of core temperature compared to an ice vest or
water immersion due to the high temperature gradient of core and skin temperature
(James et al 2015). It may be suggested that precooling with only an ice slurry will elicit
the greatest effect immediately prior to an exercise bout. The combination will lower
not only core but skin temperature as well, increasing the total heat capacity of the
body. The combination of an ice slurry and an ice vest would possibly lower core
temperature for a greater amount of time.

41

Exercise Protocol
A consideration for the results of the study is the amount of heat strain on the
subjects from the exercise protocol. It is possible that even though core temperature
did decrease during the precooling protocol. This was noticed in (Duffield et al 2007)
during an intermittent sprint protocol consisting of 15m sprint bouts interspersed with
sub-maximal exercise. This study consisted of 5x40m sprints with 30s of passive
recovery. It is assumed that a greater sprinting distance and amount of sprints would
increase heat strain significantly. It can be assumed an increased distance of forty
meters would cause a greater physiological heat strain than fifteen meters. Although 40
meters would yield greater strain, five consecutive sprints may not allow a significant
development of heat strain for a noticeable difference in performance. An important
consideration is the difference between self- paced endurance protocol and a timetrial. Ice slurry intervention seemed to have little effect on perceived thermal strain with
RPE averages being similar across all conditions. Studies like (Duffield et al 2010) noted
that perceived thermal strain affect the voluntary exercise intensity. It may be possible
that the reduction in exercise performance can be derived from sensory feedback of
thermal strain.

Ambient environment
A considerable amount of energy is wasted through heat to the ambient
environment. During exercise core temperature and skin temperature increases further
42

decreasing the gradient between the subject and the environment (Ross et al 2013). The
exercise protocol in this study was done in an indoor environment allowing consistent
environmental conditions throughout the whole study. Effective heat dissipation only
occurs when there is a properly high enough gradient to elicit heat loss from the body to
the ambient environment. The consistent low ambient indoor temperature may have
had a negative effect on performance. It is suggested in (Bongers et al 2014) that
precooling and other cooling methods may only be effective in ambient temperature
>30°C.

Fatigue
Fatigue in this study was calculated using the percent decrement formula. It was
concluded by (Glaister et al 2008) that percent decrement formula gave the most
accurate measure among other formulas and provided the best means of quantifying
fatigue in this type of activity.
Percent Decrement = (100 × (total sprint time ÷ ideal sprint time)) − 100
where Total sprint time = Sum of sprint times from all sprints.
Ideal sprint time = The number of sprints × fastest sprint time. (Glaister et al
2008)

Percent decrement measurements in this study don’t necessarily represent a steady
decline in performance. Several subjects showed steady increase in performance during
the (5x 40m repeated sprint protocol with 30 seconds of passive recovery). Regardless
43

of the improved performance for several subjects in varying precooling conditions
measurements of RPE still suggests accumilation of fatigue. Some subjects experienced
a significant increase in power output during the final sprint. Subject 7 experienced a
significant improvement in sprint time during the final sprint. Subject 7 had the highest
percent decrement value but showed the greatest improvement throughout the sprint
bouts. Subject 5 experienced their peak sprint time during their first sprint bout, and
experienced their slowest time during the third sprint.

Practical Application
The ice slurry protocol is among the most practical and convenient methods of
precooling. There was a significant difference in baseline precooling core temperature
between the control and ice slurry conditions. Control and water conditions had a mean
baseline core temperature of 36.68, 36.62℃ respectively with ice slurry condition being
36.35 ℃ respectively. This finding has a direct practical application to the development
and implementation of precooling strategies. The results show some evidence of
efficacy of an ice slurry protocol. Control and water condition had a mean RPE 11.79,
11.69 respectively with ice slurry condition being 11.39. Although there was no
significant difference in RPE found in the ANOVA the addition of more subjects may
have shown a significant difference. This exhibits evidence of a reduction in perceived
thermal stress. Although some subjects in the ice slurry protocol did show improvement
in sprint time, there was also improvement throughout all the conditions. This can be
mitigated by the inclusion of additional sprints and the ignorance of the amount of
44

sprints for the participant. The addition of a proper measurement of exercise strain and
fatigue such as heart rate would aid in assuring this result. This finding can help increase
the prevalence of an ice slurry protocol during an exercise regimen or sport game.

Future Recommendations
The purpose of this study was to investigate the effects of an ice slurry on a
repeated sprint running protocol (5 x 40m, 30 seconds of passive recovery) on
recreationally trained males. Participants were asked to abstain from caffeine and
vigorous exercise 24 hours prior to each trial. Participants were asked also to be 3 hours
post absorptive prior to each trial. Although some measures were taken to ensure
consistency of results it is recommended that recording participant consumption
outside of laboratory time could have led to more consistent results. A food diary and a
more regimented eating plan and schedule may have mitigated this variable.
A total of 13 participants were recruited for the current study. The results did
show some trends such as RPE. The amount of subjects recruited could have affected
this result. Additional subjects may have resulted with a significant difference for rate of
perceived exertion. There was some improvement in sprint time found in the ice slurry
condition and other conditions. The addition of more subjects may have resulted in a
significant difference in sprint time and or fatigue decrement.
The current study consisted of 5 x 40m sprint protocol with 30s of passive
recovery. This protocol compared to other protocols found may not have induced
enough heat accumilation to elicit fatigue for the participants. It would be
45

recommended then to add more sprint bouts for the exercise protocol to induce more
fatigue. Pacing with this sprint protocol is also something to consider. The participants
knowing the protocol was only five sprints could have paced themselves during the
initial sprints and later improved during the subsequent sprints. This would explain the
actual improvement of sprint time during the later sprints during the exercise protocol.
Future studies will have to consider withholding this information from the participant to
ensure maximal effort through every sprint bout. Rate of perceived exertion is only one
subjective measurement for fatigue. Proper measurement of the participants heartrate
could have also shown possible pacing issues. It would have also been another metric in
order to measure the degree of fatigue for the participants.

Conclusion
The purpose of this study was to investigate the effects of an ice slurry on a
repeated sprint running protocol (5 x 40m, 30 seconds of passive recovery) on
recreationally trained males. It has been shown in this study that an ice slurry precooling
protocol is an effective means of lowering core body temperature prior to exercise and
made a significant difference in baseline core temperature. Although precooling was
effective at lowering core temperature it had virtually no effect on sprint measurements
in this study. Several considerations include a lack of properly trained males, exercise
protocol chosen and a thermal neutral environment. The lack of sprint trained males
and low number of sprints with the inclusion of pacing may contributed to the
improvement of sprint velocity during subsequent sprints. This has a caused the data to
46

not show a proper decrement in fatigue and therefore are incapable of establishing if
any affect occurred from the precooling protocol. The exercise protocol selected was a 5
x 40m sprint protocol with 30 seconds of passive recovery. This protocol although
simulates an athletes distance and recovery time during a sport event, it may not have
had such a great effect on core temperature to elicit fatigue. Lastly the ambient
environment chosen was a thermal neutral environment of ~20 ℃ with ~ 55% humidity.
This temperature and humidity combination may not have contributed enough to the
increase of core temperature and thus did not show the beneficial effects of the
precooling protocol selected. Ice slurry precooling protocol may still have beneficial
effects to sport and exercise performance but more research is required.

47

APPENDIX A

48

APPENDIX B
Informed Consent
Effects of Ice Slurry Beverage on Recreationally Active Adults during Repeated Sprint
Protocol
1. Henry A. Castejon, who is a student in the Exercise Science Master’s Degree Program,
has requested my participation in a research study at East Stroudsburg University. The
title of the research is: Effects of Ice Slurry Beverage on Recreationally Active
Adults during Repeated Sprint Protocol.
2. I have been informed that the purpose is to examine the effects of ice slurry precooling on a repeated sprint running protocol (5 x 40m, 30 seconds of passive recovery).
3. My participation in this study will involve ingesting an ice slurry and water for 30
minutes prior to the repeated sprint protocol. I will participate in a familiarization
protocol consisting of 3 maximal sprints. During the next three visits of experimental
protocols I will be participating in all three, ingesting either an ice slurry, water or
nothing prior to starting a 5x 40 meter repeated sprint protocol with 30 seconds of
recovery.
4. I understand that there are foreseeable risks or discomforts to me if I agree to
participate in the study. The possible risks include muscle soreness, muscle strains, and
the possibility of other minor musculoskeletal injuries during or after the exercise
protocols.
5. There are no feasible alternative procedures available for this study.
6. I understand that the possible benefits of my participation in this research include
learning my sprint time and power output during running repeated sprint. I will also be
aiding the researcher in investigating more about pre-cooling protocols and whether or
not it improves athletic performance.
7. I understand that the results of the research study may be published but that my
name or identity will not be revealed. In order to maintain confidentiality of my
records, Henry A. Castejon will provide me with a subject code and that will be the only
way data will be identified. I also understand Henry A. Castejon and the thesis chair will
be the only people with accesses to any confidential records.
8. I have been advised that the research in which I will be participating does not involve
more than minimal risk. The only foreseeable risk of injury is musculoskeletal in nature
49

and can be handled by either the University Health Center or a Certified Athletic Trainer.
Due to athlete and student status all subjects have access to a certified athletic trainer,
access to the university health center located on campus, and access to Pocono Medical
Center adjacent to the university.
9. I have been informed that I will not be compensated for my participation.
10. I have been informed that any questions I have concerning the research study or my
participation in it, before or after my consent, will be answered by Henry A. Castejon or
Matthew Miltenberger, thesis chairperson, 200 Prospect Street, East Stroudsburg Pa,
18301, Office #5 Koehler. mmiltenber@esu.edu
11. I understand that in case of injury, if I have any questions about my rights as a
subject/ participant in this research, or if I feel I have been placed at risk, I can contact
the Chair of the Institutional Review Board: Dr. Shala Davis at 570-422-3336, East
Stroudsburg University.
12. I have read the above information. The nature, demands, risks, and benefits of the
project have been explained to me. I knowingly assume the risks involved and
understand that I may withdraw my consent and discontinue participation at any time
without penalty or loss of benefit to myself. In signing this consent form, I am not
waiving any legal claims, rights, or remedies. A copy of this consent form will be given
to me.
Subject’s Signature _________________________ Date _______________
13. I certify that I have explained to the above individual the nature and purpose, the
potential benefits, and possible risks associated with the participation in this research
study, have answered any questions that have been raised, and have witnessed the
above signature.
14. I have provided the subject/ participant a copy of the signed consent document.
Signature of Investigator _________________________ Date ______________

THIS PROJECT HAS BEEN APPROVED BY THE EAST STROUDSBURG UNIVERSITY OF
PENNSYLVANIA INSTITUTIONAL REVIEW BOARD FOR THE PROTECTION OF
HUMAN SUBJECTS

50

APPENDIX C
DATA COLLECTION SHEET
Participant Name:________________ Age:_____ Height (cm):_____ Weight (kg):_____

Precooling
10 Min
20 Min
30 Min

Control

Sprint Core Temp
S1
S2
S3
S4
S5

Control

Water

Ice Slurry

Water

Ice Slurry

Sprint RPE
S1
S2
S3
S4
S5

Control

Water

Ice Slurry

Sprint Time
S1
S2
S3
S4
S5

Control

Water

Ice Slurry

51

Sprint
S1
S2
S3

Familiarization

APPENDIX D

52

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and comparative physiology, 295(6), R1991–R1998.
https://doi.org/10.1152/ajpregu.00863.2007
Bishop, D., Girard, O., & Mendez-Villanueva, A. (2011). Repeated-sprint ability - part II:
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