ArticlePDF Available

Abstract

The aim of this study to investigate the relationships among hydration status level, sprint time performance capabilities and physiological responses [blood pressure, heart rate and rate of perceived exertion (RPE)] during a 15m Repeated Sprint Ability (RSA) training session. Fifteen male participants with a mean age 21 ± 1 years old, total mean body weight of 63.21 ± 8.25kg, and mean body height of 1.68 ± 0.05m voluntarily participated in this study. The participants underwent an RSA session with all measurements of interest were conducted pre, during and post session. Paired sample t-test was used to analyse the hydration status (urine specific gravity), with repeated measure ANOVA was used to compared the sprint time and physiological responses. Pearson correlation was utilised to determine the relationship between hydration status, sprint time, heart rate response, blood pressure and RPE during the training session. The results indicated no significant changes in hydration status. However, there was a significant difference in body mass loss before and after the training. Sprint time performance indicated no significant differences between all sets involved, indicating steady state sprint performance. The physiological responses showed a significance increase during this 15m sprint training. Correlation values for sprint time and RPE versus hydration status demonstrate a significant and strong linear relationship. As a conclusion, 15m RSA for 3 sets of 5 repetitions have no significant effects on hydration status, with sprint time performance are not influenced by hydration during an RSA session. However, as participants trying to maintain sprint time performance, physical stress do increase and thus making it difficult to improves sprint time performance. Further studies on muscle metabolic factors are suggested for future research works.
JPASPEX (2014) 2(2), 06-16
http://www.jpaspex.com e-ISSN 2289-5817
Hydration status, sprint performance and physiological responses during re-
peated sprint ability (RSA) training session
Raiza Sham Hamezah , Normah Jusoh, Nur Ikhwan Mohamad
Faculty of Sports Science & Coaching, Sultan Idris Education University
Abstract
The aim of this study to investigate the relationships
among hydration status level, sprint time performance
capabilities and physiological responses [blood pressure,
heart rate and rate of perceived exertion (RPE)] during a
15m Repeated Sprint Ability (RSA) training session.
Fifteen male participants with a mean age 21 ± 1 years
old, total mean body weight of 63.21 ± 8.25kg, and mean
body height of 1.68 ± 0.05m voluntarily participated in
this study. The participants underwent an RSA session
with all measurements of interest were conducted pre,
during and post session. Paired sample t-test was used to
analyse the hydration status (urine specific gravity), with
repeated measure ANOVA was used to compared the
sprint time and physiological responses. Pearson
correlation was utilised to determine the relationship
between hydration status, sprint time, heart rate response,
blood pressure and RPE during the training session. The
results indicated no significant changes in hydration
status. However, there was a significant difference in
body mass loss before and after the training. Sprint time
performance indicated no significant differences between
all sets involved, indicating steady state sprint
performance. The physiological responses showed a
significance increase during this 15m sprint training.
Correlation values for sprint time and RPE versus
hydration status demonstrate a significant and strong
linear relationship. As a conclusion, 15m RSA for 3 sets
of 5 repetitions have no significant effects on hydration
status, with sprint time performance are not influenced by
hydration during an RSA session. However, as
participants trying to maintain sprint time performance,
physical stress do increase and thus making it difficult to
improves sprint time performance. Further studies on
muscle metabolic factors are suggested for future research
works.
Keywords: Blood pressure, heart rate, hydration status,
RSA, sprint time
Introduction
Maintaining hydration status is considered important for
sports performance as well as physical well-being.
Neural, hormonal, metabolic and mechanical aspects
involved in any physical training including sprint training
are greatly influenced by the level of fluid available in the
body (Kraft, et al., 2010). Fluid or water plays a
fundamental role in the body as it functions as the
solvents for nutrients, transport of nutrients to muscle
cells, helps body eliminates waste products, maintenance
of constant body temperature and protection of the fetus
during pregnancy (Armstrong, 2007; Sawka, et al., 2007).
A number of methods have been used to assess and
quantify hydration status and changes in hydration status.
Acute changes in body mass over a short time period can
frequently be assumed to be a result of body water loss or
gain as 1ml water has a mass of 1g and therefore changes
in body mass can be used to quantify water gain or loss
(Lentner, 1981). Other methods in assessing hydration
status are by measuring blood and urine indices while
determination of perception of thirst is categorized as a
subjective method in hydration assessment (Armstrong,
2007, Gonzalez-Alonso, Calbet & Nielsen 1999;
Shirreffs, 2000).
Maintaining an appropriate level of hydration
status during training may positively influence blood
volume, cardiac output (Gonzalez-Alonso, Mora-
Rodriguez, & Coyle, 2000) muscle blood flow (Gonzalez-
Alonso, Calbet, & Nielsen, 1998, 1999), core and muscle
temperatures (Murray, 2007). Dehydration of
approximately 3% body mass loss has deleterious effects
in physiological and performance-influencing variables
such as reduced motor performance, reduced muscular
endurance, cardiovascular drift, reduced sweat rate, blood
volume and heat dissipation in addition to heat illness
(Heaps, Gonzalez-Alonso, & Coyle, 1994; Oppliger &
Bartok, 2002; Sawka, 1992). This suggests that
hypohydration is an important factor to consider when the
athlete involve in exercise trainings, considering the ef-
fects on the adaptations in muscle, hormonal control,
neural control, metabolism, and cardio-respiratory
function with both aerobic and anaerobic trainings.
One previous study has indicated that there is no effect of
moderate hypohydration or hyperthermia on anaerobic
exercise performance in a temperate environment
(Cheuvront, Carter, Haymes, & Sawka, 2006). Another
study suggested that body mass reductions of 2–3% had
no significant effect on sprint performance (Watson, et
al., 2005).Thus, it is a question whether is there any
relationship between hydration status, and sprint
performance during the repeated sprint ability training
session?
In terms of the repeated sprint ability (RSA), it is
the ability to produce the best possible average sprint
performance over a series of sprints (≤10 seconds),
separated by short (≤60 seconds) recovery periods (Bish-
op, Girard, & Mendez-Villanueva, 2011). RSA is
Research article
6
Raiza Sham Hamezah et al. Hydration status, sprint performance and physiological responses during repeated sprint ability (RSA)
therefore an important fitness requirement for team-sport
athletes. For activity pattern like short burst sprint, it
consists of (≤6 -second) maximal work, with a single
short sprint (5- to 6-second), adenosine triphosphate
(ATP) is resynthesized predominantly from anaerobic
sources (phosphocreatine [PCr] degradation and
glycolysis), with a small (<10%) contribution from
aerobic metabolism (Aerenhouts, Zinzen, & Clarys 2011;
Boutcher, 2010). A typical sprint training session usually
takes approximately between 40 minutes to 60 minutes;
whereby the athletes will repeat the sprint for several
repetitions. While the short sprint in a single manner does
not affect hydration status, but repeated over several times
for about one hour may have a significant effect on
hydration status. The most important rule in generating
the most benefits in long term training is to maximize
acute stimulus and adaptation in each training session.
Thus, if the single training session is lacking in terms of
its` quality of performance (acute stimulus) due to
hydration status, the cumulative adaptation longitudinally
might also be impaired. However, this assumption is in
need of further investigation, in which why this study was
done. To conclude, the main aims of this research was to
investigate the relationship of hydration status level, with
their sprint time performance, heart rate response, blood
pressure and rate of perceived exertion (RPE) during the
RSA training session.
Methodology
Participants
Fifteen male participants aged 21.0 ±1 years old, total
mean body weight of 63.21 ± 8.25kg, and mean body
height of 1.68 ± 0.05m were recruited in this study.
Participation was on voluntary basis and approval from
the Faculty’s Research Committee was obtained prior to
data collection. The participants were healthy and free
from injury during the time of the study, and had no
serious injury records within the past 6 months that might
affect the study outcomes.
Equipments
Body weight and height of the subjects were measured by
using a weight scale (Omron HN-283, Kyoto, Japan) and
stadiometer (portable Height Scale-Mentone/PE87,
Australia) respectively. A digital hand-held `pocket` urine
specific gravity refractometer PAL-10S (ATAGO, Japan)
was used to assess hydration status along with hydration
status colour coded strips; (AMES, Multistix 10SG Rea-
gent Strips for Urinalysis, China) with sprint performance
time were recorded using a stop watch (Q&Q,CAL.HS4,
Tokyo, Japan). The 15-m sprint distance was measured
using a digital roller measuring wheel. Portable wrist
digital blood pressure monitor (HEM- 6200, Omron,
Kyoto, Japan), was used to assess blood pressure and
heart rate while Borg`s Scale was used to measure the
rate of perceived exertion (RPE) across all repetitions.
Environmental conditions were recorded using a Wet
Bulb Globe Temperature (WBGT-103 Heat Stroke
Checker, Japan).
Procedures
All participants attended two sessions. During the first
session, the participants were briefed about the study, and
were asked to sign the participation consent letter once all
their questions had been answered; and the participants
voluntarily indicated their willingness to participate in
this study. Each participant was reminded that they were
allowed to quit the study at anytime, without the need to
give any reason for the withdrawal. Body height and
pre-participation body weight were measured in session
one, and Body Mass Index (BMI) were calculated from it.
The participants were also told and demonstrated on how
to correctly wear the blood pressure monitor on their
wrist. The second session began with the measurement of
body weight, urine specific gravity and blood pressure.
The participants were then performed a standardized
warm-up and stretching exercises, followed by specific
warm-up. The specific warm-up for the training was in
the form of five standardized athletic drills. The drills
used were the ankling, high-knee, back-kick, chopping
and easy stride. All drills were performed over a 10m
distance with two repetitions each drill, except for the
easy stride that covered a 30m distance.
The participants then performed a repeated sprint
training program consisted of 5 repetitions of 15m sprint
for each set, with total set performed were 3 sets. The
duration for rest in-between each repetition was set at 60
seconds as suggested in the previous study on RSA
training (Girard, et al., 2011). Rest in-between set was 5
minutes. Each participant was asked to sprint at maximal
effort. Sprints were performed with a standing start split
stance position with the dominant leg on the front, and all
the participants were asked to wear their typically used
sports shoes. Once started, the participants sprinted from
15m starting line to the finishing line, touching it with any
foot, turning back and sprint back to the starting line for a
completion of 1 repetition. All sprint times were recorded
in the assessment form together with heart rate response,
blood pressure and RPE scores (Borg, 1998; Chen, Fan,
& Moe, 2002) before and after each repetition and set.
Urine specific gravity was measured before and after the
whole sessions, together with participants` body weight.
Each urine specific gravity measurement was performed
in 2 methods; refractometer and strips. Prior to the testing,
the refractometer was calibrated with distilled water.
Body weight was measured before, during and after
training. WBGT was used to measure the environment
temperature, humidity and wind speed during the session.
Statistical Analysis
Statistical Analysis for Social Sciences (SPSS) version
17.0 was used to perform all statistical analyses of the
data collected, with alpha level for significant was set at
0.05. For descriptive data (body mass, age, height and
BMI), mean and standard deviation of all participants
were calculated. As all of the data had been determined
normally distributed, urine specific gravity for both
methods via refractometer and strips had been compared
using paired sample t-test. Sprint time, heart rate, blood
pressure and RPE comparisons were analysed using
repeated measure ANOVA. Bonferroni post hoc test was
used for significance differences found. Pearson
Correlation was used to determine the relationship
between hydration status and sprint performance (sprint
time).
7
JPASPEX (2014) 2(2), 06-16
http://www.jpaspex.com e-ISSN 2289-5817
Figure 1: Schematic diagram of the study procedure
Results
Table 1 showed urine specific gravity (USG) level,
measured by using 2 methods, which were
refractometer and strip. There were no significance
differences (p>0.05) for mean urine specific gravity for
both refractometer and urine strip. No changes was
observed for urine specific gravity (refractometer)
between set 1(1.013 ± 0.010) and set 3 (1.013 ± 0.008).
For urine specific gravity using the urine strips, the
mean value was slightly lower during pre set 1(1.012 ±
0.007) than post set 3 (1.013± 0.008). On the other
hand, there was a significant change in mean body
weight, which was lower in post set 3 (62.97± 8.23kg)
compared to pre set 1(63.21± 8.25kg). Mean for
percent body weight loss was 0.38 ±0.14%.
Table 1: Urine Specific Gravity(USG) before and after
15m RSA sprint training. Values are Mean ± SD.
Variables
Pre set 1
Post set 3
P value
Mean ±
SD
Mean ± SD
USG
(refractometer)
1.013
± 0.010
1.013 ±
0.008
0.984
USG (strip)
1.012
±0.007
1.013±
0.008
0.803
Body mass (kg)
63.21
± 8.25
62.97
± 8.23
0.000*
*Significant at p<0.05
Table 2 indicates the results for the sprint time
performance and physiological changes which includes
blood presure, heart rate and rate of perceived exertion
(RPE) throughout the training session. Results for
mean sprint time showed no significant differences
( p>0.05) across the training session. However, there
were significant differences for mean heart rate
(p<0.001), blood pressure (p<0.05) and RPE
(p<0.001). Bonferoni post hoc revealed that mean heart
rate during set 1 (122 ± 9bpm) was significantly lower
(p=0.001) than set 2 (138 ± 12bpm). Likewise, mean
heart rate during set 1 was significantly lower
(p=0.005) than set 3 (144 ± 11bpm). On the other
hand, there was no significance difference (p=0.450)
between set 2 and set 3. Systolic pressure was
significantly higher during set 1(143 ± 22mm/Hg) than
set 2 (133 ± 13mm/Hg) and set 3(127 ± 18mm/Hg).
While for diastolic pressure, was significantly higher
during set 3(107 ± 27mmHg) than set 1(94 ± 17mmHg)
and set 2 (87 ± 13mmHg).
Table 2: Sprint time, blood presure, heart rate and rate
of perceived exertion (RPE) during 15m sprint training.
Values are mean ± SD
Set 1
Set 2
Set 3
P
value
Mean ±
SD
Mean ±
SD
Mean ±
SD
6.69
±0.07
6.60
±0.08
6.61
± 0.11
0.393
Heart rate (bpm
)
122
± 9
138
± 12
144
± 11
0.000*
systolic
143
± 22
133
± 13
127
± 18
0.021*
diastolic
(mmHg)
94
± 17
87
± 13
107
± 27
0.020*
4 ± 2
5 ± 2
6 ± 2
0.000*
*Significant at p<0.05
8
Raiza Sham Hamezah et al. Hydration status, sprint performance and physiological responses during repeated sprint ability (RSA)
Pairwise comparisons showed there were significance
RPE value for each set involved. Mean RPE was
significantly higher during set 3 (6 ± 2) compared to
set 2 (5±2) and set 1 (4±2), with p value stated p=0.000
and p=0.007 respectively. Similarly, mean RPE for set
2 (5±2) also was significantly higher (p=0.028) than set
1(4±2). To conclude, except the sprint time, the other
physiological changes (heart rate response, blood
pressure and RPE) showed a significance differences
during this 15m sprint training.
Table 3 demonstrates the correlation Pearson
results between hydration status and the sprint time,
heart rate, blood pressure and rate of perceived exertion
(RPE) during 15m RSA sprint training. There was a
significantly high correlation between hydration status
and sprint time (r=0.967, p<0.05) as well as RPE
(r=0.896, p<0.05). On the other hand, there were a
moderate correlation observed between hydration
status and heart rate response ( r=0.587, p>0.05) and
weak correlation with systolic and diastolic blood
pressure (r=0.475,p>0.05), (r=0.221, p>0.05).
Table 3: Correlation between hydration status, sprint
time, heart rate, blood pressure and rate of perceived
exertion (RPE) during 15m RSA sprint training
Hydration status vs:
R
P
value
Sprint time (s)
0.967
0.012
*
Heart rate (bpm )
0.587
0.153
Blood pressure systolic
(mmHg)
0.475
0.200
Blood pressure diastolic
(mmHg)
0.221
0.336
RPE
0.896
0.037
*
*Significant at p<0.05
Environmental condition of pre, during and post RSA
session indicated normal temperature for Malaysian
climate as indicated in Table 4. The environmental
condition observed during the data collection session
was a similar environmental condition typically
experienced by all participants, during their other
exercise and training sessions.
Table 4: Environmental condition across the 15m RSA
sprint training
Pre
During
Post
Aver-
age
Outdoor WBGT
(ºC)
28.8
26.4
27.1
27.4
Ambient tem-
perature (Ta)( ºC)
29.0
27.6
27.3
28.0
Relative humidity
(RH)( %)
Globe Tempera-
ture (Tg) ( ºC)
88.2
31.9
91.1
28.3
96.8
26.6
92.0
28.9
Discussion
Repeated sprint ability (RSA) as a popular method of
training especially for speed and agility development
among team sports athletes has only started to be quite
popular recently. Although usage of similar methods
existed for quite some time and known by most
practitioners (coaches), it was not widely researched
previously. It has been quite difficult to explore the
characteristics and features of RSA, because of the
spontaneity of player movements, as example during
field-based team sports (Spencer et al. 2005).
Repeated sprint ability (RSA) training
involves several tests including number of sprint
repetitions sprint duration, duration, recovery, type of
recovery, form of exercise and training status (Galvin,
et., al., 2013; Spencer, Bishop, Dawson, & Goodman,
2005). However, RSA durations, number of sets, and
recovery time are varied from one study to another. For
instance, this research approached the mode of total 3
sets with 5 repetitions of 15m sprint for each set. The
duration for rest in-between each repetition was at 60
seconds while rest in-between set was 5 minutes, re-
ferred to previous repeated sprint ability(RSA) training
research (Girard et. al, 2011). Discussions in this
section thus might not be able to be fully compared
with other studies with different set-up and
configurations. However, what will be discuss here
will be highly correlates with the findings of the
study and scientific base theory of it.
Hydration status level and changes in hydration sta-
tus across the training
In this study, there were two different kinds of methods
to assess the hydration status of the participants.
Hydration status was assessed by measuring urine
specific gravity (USG) using refractometer and strip.
Based on the t test result for pre and post data, the
refractometer result indicated 1.013 ± 0.010 for pre set
1and 1.013 ± 0.008 collected for post set 3. For the
strip result, mean for pre set 1 is 1.012 ± 0.007 while
mean for post set 3 showed 1.013± 0.008. From the
results, it can be concluded that there were no
significance changes that had been notified in
hydration status among the participants across the RSA
training session.
As indicated by Casa et. al (2000) in the in-
dexes of hydration status for urine specific gravity, a
person is well hydrated if the USG value is less than
1.010, minimal dehydration is in range of 1.010
1.020 while 1.021-1.030 is categorized as a
significant dehydration. The worst state of hydration
status level is when USG reading is more than 1.030,
which it is categorized as in serious dehydration level.
In this study, the participants` USG level was between
1.012-1.013. A comparison of these values to the
guidelines of the National Athletic Trainers’
Association suggests the participants were categorized
in the minimal dehydration level (Casa et. al, 2000).
This is however explained that participants were
already experience slightly dehydrate prior to the
training session.
9
JPASPEX (2014) 2(2), 06-16
http://www.jpaspex.com e-ISSN 2289-5817
The USG reading might as well linked to the
environment and temperature on the time the data
collection had been carried out. As the data was col-
lected in the evening environment condition with
average outdoor WBGT temperature was 27.4ºC and
92% relative humidity, it might appear to have an ef-
fect on the outcome. While the data collection was took
place in the evening, the participants` hydration level
might have been influenced by their activities
throughout the day before they came to the RSA
training session. Therefore, it can yield contradictory
result which showed participants were already in a
minimal dehydration level even since before the
training session began. In this study, USG were
collected in the evening, before and after the training
session, might not be as accurate as USG reading on
the first urine in the morning, as hydration status can
be influenced by many factors.
Nevertheless, pre and post the 15m RSA
sprint session’s showed that there were no significant
changes can be observed for both USG reading via
refractometer as well as from the strip readings.
However, the hydration level was maintained in mini-
mal dehydration, with no alteration in hydration status
detected towards the end of the training session. The
USG result of this study were in agreement with the
National Athletic Trainers" Association in their
position statement for fluid replacements for athletes,
which recommends that athletes should begin activity
with a USG at or below 1.020 to ensure adequate
hydration (Casa et. al,2000).
Conversely, the participants` body mass result
showed a significant difference between pre and post
RSA session, with a decrease in body weight
measurement observed. The result was 63.21kg± 8.25
for pre set 1 and 62.97kg± 8.23 for post set 3.
However, the percent body weight loss showed only
0.38± 0.14% of body mass loss overall. If the percent
body mass loss are less than 1%, assumption can be
made that participants were not dehydrated (Casa
et.al., 2000). It is suggested that participants only in the
state of mild hypohydration or would represent a
normal variation of body mass on day to day basis.
Previous research stated that minimal percent
of body weight loss that will started to compromosie
body function or performance are between 1-2 %
(Maughan, 2003; Armstrong et.al., 2012). Cheuvront,
Carter & Sawka (2003) reported similar results where
they stated that exercise performance decrement were
only evident when the body mass loss is more than 2%.
This view is supported by Cheuvront et. al (2004).
Their study assessed 65 healthy men which underwent
moderate intensity walking in the heat for 2-3 hours.
Our findings was in agreement with their results which
stated that the variability in body mass of 1.1% or less
from the baseline was just an indication of daily water
body turn-over or individual`s regular body mass
deviation. Therefore, for this present study, a reduction
of 0.38% of body mass, with a very small amount of
water loss can be safely said as not an indication of
further dehydration among the participants involved.
As a conclussion, participants began the 15m
sprint training in a minimal hypohydration state, as
indicated by USG and strip. The hydration level was
maintained from initial towards the end of the training
as no significance hydration changes was detected
among the participants. It is also suggested that 0.38±
0.14% of body mass loss among the participants, which
is less than1% body mass reduction from baseline, may
just only lead to very mild hypohydration and do not
appear to be associated with further dehydration levels.
Sprint time performance before and after RSA
Overall, results for mean sprint time indicated no
significance differences across the training session.
Albeit that, it somehow showed a slight trend of
decrement in the sprint performance of the participants.
As showed in the Table 2, mean sprint time for set 1
started with 6.69 ±0.07s and decrease to 6.61± 0.11s
towards the end of set 3, however can demonstrate as a
persistent state of sprint performance.
Explanation accounting for the nearly
constant state of this sprint time may include that
participants might gave all out sprinting in the initial
phase with a burst and recover (rest in between) each
repetition that can offer the participants to continuous
anaerobic exercise. This suggested that participants
were involved in a high energy exercise with low rest
intervals between each repetitions and sets, which it
might help out participants to sprint with the maximum
capacity for the next repetition. Furthermore, the sprint
time seem to be in a steady state, can be understandable
as the shift of dominance energy system started to
happen. With aerobics energy systems comes more into
play, it is suggested that it helps the participants to
have a more constant performance.
These present findings are comparable to a
study by Thébault, Léger, and Passelergue (2011).
Their research was on repeated sprint ability and
aerobic fitness (n=19), in which their assessment
involved the RSA test (3 sets of 5 40-m sprints with
1-minute rest between sprints and 1.5 minutes between
sets). Their results showed that subjects with greater
maximal aerobic speed competent to maintain almost
constant level of speed across the RSA sets and
repetition of repeated sprints and achieved better
recovery between series. Another study by, Cheuvront
et. al (2006) also explored the effects of hypohydration
and moderate hyperthermia (core temperature
elevation) on anaerobic exercise performance in a
temperate environment. Their study involved a single
15-s Wingate anaerobic test (WAnT) which was used
to assess anaerobic performance (peak power, mean
power, and fatigue index). Their results indicated that
there was no significant changes of the performance,
neither moderate hydration group nor the moderate
hyperthermia affected anaerobic exercise performance
in a temperate environment.
In summary, the persistent state of the sprint
time across the 15m RSA training session somehow
could illustrate the participants` good combination of
aerobic capacity (which is supported by aerobic
10
Raiza Sham Hamezah et al. Hydration status, sprint performance and physiological responses during repeated sprint ability (RSA)
metabolism in order that exercise can be performed for
extended time) as well as anaerobic capacity (which is
utmost stressed in high intensity activities but in short
duration). Participants can cope well with the training
methods in cumulative ways as in this case,
participants were able to continually reproduce short
burst of maximal sprint, repeatedly with short recovery
period. It is suggested for further research, to explore
the relationship of volume of oxygen maximum
(VO2max) for the aerobic capacity, along with
anaerobic threshold or lactate threshold measurement
during this type of repeated sprint ability training for
more precision details.
Heart rate responses during a 15m RSA sprint train-
ing session
Heart rate response was one of the physiological
changes that were evaluated during this 15m RSA
sprint training session. Participants` heart rate was
measured immediately after finishing of each set. The
results for heart rate responses across the training
yielded a significance increment. The heart rate
response were identified to increase gradually from set
1 (122±9bpm) towards set 3 (144± 11bpm). Bonferoni
post hoc via pairwise analysis revealed that mean heart
rate for set 1 was significantly lower than set 2.
Likewise, set 1 also showed a significantly lower than
set 3. This finding is in line with the results of a
study by Cheuvront et. al (2005). Their study
investigated hypohydration effects on endurance exer-
cise performance in two conditions (temperate or cold
air) using eight subjects. Their study found that heart
rate was significantly higher at 30min within the
temperate trial. Similar results obtained from a research
by Gonzalez et. al (1999), where their study investi-
gated the influence of body temperature on the devel-
opment of fatigue during prolonged exercise in the
heat. Their findings showed an increment in heart rate
while stroke volume was observed to be reduced
paralleled the rise in core temperature (36-40ºC).
Overall, present study indicated heart rate re-
sponse significantly increased in a linear line, in
proportion to the exercise intensity and duration, while
performing the 15m RSA sprint training (p<0.001). As
this sprint training session only involved 30 seconds of
recovery time between each repetitions, and 5 minutes
between each sets, the heart rate tend to rise
incrementally across the training session and having
peaks at the end of sets.
Blood Pressure during a 15m RSA sprint training
session
As indicated in Table 2, significant differences
observed between sets (p=0.021) in post-exercise sys-
tolic blood pressure level with lower post exercise
reading. Diastolic blood pressure on the other hand was
found to be fluctuated from start to end of the RSA
session, with significant difference observed with
minimal increment post exercise (p=0.020).
The post-exercise hypotension in which the
systolic level was found to be significantly lower is an
acceptable in normal condition, as studies have shown
that immediately post-exercise, blood pressure level
will be much lower than the reading recorded prior to
exercise (Pescatello et. al, 1991; Syme et. al, 2006; de
Salles et. al, 2010).
Initially, the assumption was that apart from
normal regulatory effect for recovery after exercise, the
lower blood pressure might also due to the effect of
excess post-exercise oxygen consumption (EPOC).
However, previous study has suggested that this is not
the cause due to different time course of action
(Williams et. al, 2005). Systolic blood pressure was an
indicator of the blood flow in the arteries. The harder
the exercise, the more blood will be delivered in the
arteries, thus higher systolic blood pressure level. The
diastolic blood pressure was an indicator of pressure in
the arteries, when the heart was relaxed (after each
pumping out). In order to allow more oxygen delivered
to the whole body, the blood vessels will be more
relaxed (for wider diameter, more blood flow). This
resulted in the lower systolic level. Similar study on
circuit based exercise also yields similar result
(Paoli et. al, 2013).
In relation to this, the researcher based on
above reasons suggested that participants involved in
this study were basically active and possess a strong
heart which can pump more blood with less effort.
Since exercise is understood to reduce resistance in
arteries, it consequences was that the blood flow more
freely. Hence, if the heart can work less to pump blood
for muscles and overall body used, the force on the
arteries decreases and end with the lower blood
pressure. This result advocate one of the benefits of
this type of exercise is lower blood pressure level,
which can be used as an anti-hypertensive exercise.
Though, this requires further investigation.
Rate of perceived exertion (RPE) during a 15m RSA
sprint training session
It’s quite interesting to be noted that while both
hydration status and sprint time performance were
found to be insignificantly change during the three sets
of RSA performed in this study, RPE measurements
indicated otherwise.
This result is in line with other findings which
demonstrated that ratings of perceived exertion were
increased along with the exercise intensity or duration.
A study by Cheuvront et. al (2005) compared the effect
of hypohydration on endurance exercise performance
in temperate and cold air environment, also
demonstrated an increment of RPE over time of
training. On the other hand, the consequence of
physiological changes, as example the constriction of
peripheral blood vessels to maintain blood pressure,
decreased stroke volume, decreased in cardiac output
and increased stroke volume may bring out a negative
outcome on RPE. Moreover, a greater perception of
exertion also can be lead by the decreased of plasma
volume changes throughout the training session
(Aldridge, Baker & Davies, 2005). As this may advise
11
JPASPEX (2014) 2(2), 06-16
http://www.jpaspex.com e-ISSN 2289-5817
that the other physiological changes are basically
connected to each other and may influence to the other
responses to the body.
As RPE was measured based on verbal responses
from the participants, it reflected the feelings, sensa-
tions and physical stress experienced by the
participants during the protocol. If hydration status or
heart rate (as indicated by the results) did not play the
role in promoting the uneasiness experienced by the
participants, another possible explanation might be
purely be on psychological and muscle metabolism
factors. However this was not measured in this study,
and thus leaves the assumption to be verified in future
studies. But for the discussions, other studies have
shown that while level of fluid in the body were not
significantly affected, blood lactate accumulation in the
muscle may have increase the level of difficulty for the
muscle to contract at a much faster rate (muscle buffer
capacity) (Bishop, Edge, & Goodman, 2004), although
participants had increased their physical effort.
Previous study have shown that phosphagen system is
the main energy system used during an RSA session
performed by professional rugby rules players (elite
athletes) (Wadley & Le Rossignol, 1998). Thus for
participants which was not in elite category such as
participants of this study, their energy source might be
derived dominantly from both anaerobic energy system
(phosphagen and glycolysis). Glycolysis produce blood
lactate as their by-product (Gastin, 2001).
However, it must be noted that other activities, in
addition to sprinting, may lead to fatigue during
team-sport competition such as energy expenditure
during eccentric contractions, change of direction
movements and jogging or striding for extended peri-
ods could also contribute to fatigue (Spencer et. al,
2005). It is evident that the anaerobic ATP production
during short-duration sprinting is provided by
considerable contributions from both PCr degradation
and anaerobic glycolysis, confirming the significance
of glycolytic activity during this type of exercise. The
importance of anaerobic glycolysis is supported by the
fact that PCr stores are only partly depleted during
short duration sprinting.( Spencer et. al, 2005).
In summary, RPE increased significantly across
the training session. Nevertheless, it is evident that
each of the variables which is exercise mode, sprint
duration, sprint repetitions, recovery duration and type
of recovery can significantly affect participant`s RPE
as well as their performance.
Correlation between hydration status, sprint time,
heart rate response, blood pressure and RPE
Based on the correlation result between hydration sta-
tus and sprint time of the subjects, the data indicated
high correlation with the value of r= 0.967,p=0.012.
Based on present study hydration status data, the mean
of urine specific gravity showed no changes across the
test, which the value was 1.013 ± 0.01. It means that
hydration level was maintained in the steady state
(minimal dehydration) throughout the training session,
while the sprint time showed almost constant with a
slight of decrement of sprinting time.This finding is in
line with the results of Morris et. al (1998) in their
study to determine the effect of hot environment on
performance of prolonged, intermittent, high intensity
shuttle running. The results between the two trials of
12 active sportsmen showed a decrement in
performance occurred although no differences were
identified in the level of dehydration, rating of
perceived exertion, blood glucose and lactate, plasma
free fatty acid and ammonia concentrations.
Furthermore, , Baker et. al (2007) who observed among
the basketball player, stated that a progressively greater
decline in basketball playing ability as dehydration
progressed from 1 to 4%.
This significant high correlation observed,
which hydration status affect the sprint performance
might be due to fatigue and accumulation of lactic acid
in the body. This is supported by the RPE data which
showed the RPE increase from 4 ± 2 at the beginning
and 6 ± 2 at the finishing. This showed that the subjects
were fatigue towards to the end of the test. Girard,
Mendez-Villanueva and Bishop (Girard et. al, 2011) in
their review had found similar pattern in many studies
related to RSA and fatigue using both laboratory and
field based assessment
In spite of this, non significance relationship
between hydration status and heart rate found in this
study, implying that levels of dehydration among the
participant did not affect heart rate to increase in the
training session. As participants` hydration level was
maintained in minimal dehydration level throughout
the training session, therefore it seems that hydration
status do not turn out to become a factor to impair heart
rate response. This finding was in contrary with what
has been found in another study on hydration by Carter
et. al, 2005. Their participants demonstrated heart rate
response was influenced by dehydration (3.9±0.7%
body weight loss), and it was ended with reduction of
overall heart rate response after exercise in the heat.
But again, current finding indicated only ‘mild
dehydration’; with the environment temperature can be
said as ‘normal’ to the participants, which was used to
play sports in the similar set-up and environmental
condition involved.
In term of relationship between hydration sta-
tus and blood pressure, as far as the knowledge of the
researcher, no study has been found investigating blood
pressure responses during an RSA session in relation to
hydration status. This study recorded no significance
relationship evident between hydration status and
blood pressure during RSA session. However other
studies that investigate blood pressure responses from
other types of exercise in the heat indicated that blood
pressure declined parallel with dehydration
(González-Alonso, Calbet and Nielsen, 1998;
Gonzalez-Alonso, Mora-Rodriguez and Coyle, 2000).
Research by González-Alonso, Calbet and Nielsen
(1998) investigated whether any reduction occurred on
the blood flow to exercising muscles when cardiac
output and systemic vascular conductance decline with
dehydration during prolonged exercise in the heat.
Their study was conducted on seven euhydrated,
endurance-trained cyclists performed two trials of
12
Raiza Sham Hamezah et al. Hydration status, sprint performance and physiological responses during repeated sprint ability (RSA)
cycling to exhaustion at 35ºC. Their findings
concluded that due to the decrement in perfusion
pressure and systemic blood flow, blood flow to the
exercising muscle declined significantly with
dehydration. Hence, one explanation of our no signifi-
cance relationship between hydration status and blood
pressure might be related to the static hydration level.
Nevertheless, the constant hydration level in minimal
dehydration level did influence the post exercise blood
pressure to be lower than pre exercise blood pressure.
To conclude, the present results suggest that
the ability to repeat the sprints were still tolerable
among the participants. Therefore, increase in the mode
and loading parameters of this repeated sprint ability
training can be suggested or applied in the future (such
as shorten time of recovery, increase the sets and
repetitions involved/intensity).
For future studies and implementation,
coaches or researchers involved is suggested to also
monitor or assess blood lactate accumulation during the
RSA session. It is a more precise and reliable parame-
ter to validate the physiological responses to exertion
in response to the training session involved.
As no hydration changes were observed
across the training session, the result might be different
if urine specific gravity can be obtained from the first
urine in the morning. This will allowed identification
of the actual hydration state of the participants before
beginning the testing session. It will control the
cofounding factor as the hydration level can be
fluctuating throughout the day. Future studies should
take this into consideration.
It is also can be concluded that repeated
shuttle sprints might be an effective training practice
for improving the heart rate responses, apart from their
actual purpose of developing speed and agility. The
practical implications of these findings also
suggest anti-hypertensive exercise as it might help to
lower the blood pressure. Nevertheless, these require
further studies for more improvement and to scrutinise
on all suggestion for better outcome.
References
1. Aerenhouts, D., Zinzen, E., & Clarys, P.
(2011). Energy expenditure and habitual phys-
ical activities in adolescent sprint ath-
letes. Journal of Sports Science & Medi-
cine, 10(2), 362.
2. Aldridge, G., Baker, J. S., & Davies, B.
(2005). Effects of hydration status on aerobic
performance for a group of male university
rugby players. Journal of Exercise Physiology
Online, 8(5), 36-42.
3. Aloui, A., Chaouachi, A., Chtourou, H.,
Wong, D. P., Haddad, M., Chamari, K., et al.
(2012). Effects of Ramadan on the diurnal
variations of repeated sprints performances.
International Journal of Sports Physiology
and Performance, 8(3), 254-263.
4. Armstrong, L., Maresh, C., Castellani, J., Ber-
geron, M., Kenefick, R., LaGasse, K., et al.
(1994). Urinary indices of hydration status.
International Journal of Sport Nutrition, 4(3),
265.
5. Armstrong, L. E. (2007). Assessing hydration
status: The elusive gold standard. Journal of
the American College of Nutrition, 26(5
Suppl), 575S-584S.
6. Armstrong, L. E., Ganio, M. S., Casa, D. J.,
Lee, E. C., McDermott, B. P., Klau, J. F., ... &
Lieberman, H. R. (2012). Mild dehydration
affects mood in healthy young women. The
Journal of nutrition, 142(2), 382-388.
7. Astorino, T. A., Allen, R. P., Roberson, D.
W., Jurancich, M., Lewis, R., & McCarthy, K.
(2012). Attenuated RPE and leg pain in re-
sponse to short-term high-intensity interval
training. Physiology & Behavior, 105(2), 402-
407.
8. Baker, L. B., Dougherty, K. A., Chow, M., &
Kenney, W. L. (2007). Progressive dehydra-
tion causes a progressive decline in basketball
skill performance. Medicine and science in
sports and exercise, 39(7), 1114-1123.
9. Benardot, D. (2006). Advanced sports nutri-
tion. Champaign: IL: Human Kinetics.
10. Bishop, D., Edge, J., & Goodman, C. (2004).
Muscle buffer capacity and aerobic fitness are
associated with repeated-sprint ability in
women. European Journal of Applied Physi-
ology, 92(4-5), 540-547.
11. Bishop, D., Girard, O., & Mendez-Villanueva,
A. (2011). Repeated-sprint ability - part II:
recommendations for training. Sports Medi-
cine, 41(9), 741-756.
12. Borg, G. (1998). Borg's perceived exertion
and pain scales. New York: Human kinetics.
13. Boutcher, S. H. (2010). High-intensity inter-
mittent exercise and fat loss. Journal of Obe-
sity, 2011.
14. Bowtell, J. L., Cooke, K., Turner, R., Mileva,
K. N., & Sumners, D. P. (2013). Acute physi-
ological and performance responses to repeat-
ed sprints in varying degrees of hypoxia.
Journal of Science and Medicine in Sport.
15. Buchheit, M., Abbiss, C. R., Peiffer, J. J., &
Laursen, P. B. (2012). Performance and phys-
iological responses during a sprint interval
training session: relationships with muscle
oxygenation and pulmonary oxygen uptake
kinetics. European Journal of Applied Physi-
ology, 112(2), 767-779.
16. Buchheit, M., Bishop, D., Haydar, B., Naka-
mura, F., & Ahmaidi, S. (2010). Physiological
responses to shuttle repeated-sprint running.
International Journal of Sports Medicine,
31(6), 402-409.
17. Casa, D. J., Armstrong, L. E., Hillman, S. K.,
Montain, S. J., Reiff, R. V., Rich, B. S., et al.
(2000). National Athletic Trainers' association
position statement: Fluid replacement for ath-
letes. Journal of Athletic Training, 35(2), 212-
224.
13
JPASPEX (2014) 2(2), 06-16
http://www.jpaspex.com e-ISSN 2289-5817
18. Carter III, R., Cheuvront, S. N., Wray, D. W.,
Kolka, M. A., Stephenson, L. A., & Sawka,
M. N. (2005). The influence of hydration sta-
tus on heart rate variability after exercise heat
stress. Journal of Thermal Biology, 30(7),
495-502
19. Chen, M. J., Fan, X., & Moe, S. T. (2002).
Criterion-related validity of the Borg ratings
of perceived exertion scale in healthy individ-
uals: a meta-analysis. Journal of Sports Sci-
ences, 20(11), 873-899.
20. Cheuvront, S. N., Carter III, R., Castellani, J.
W., & Sawka, M. N. (2005). Hypohydration
impairs endurance exercise performance in
temperate but not cold air. Journal of Applied
Physiology, 99(5), 1972-1976
21. Cheuvront, S. N., Carter, R. I. I. I., Montain,
S. J., & Sawka, M. N. (2004). Daily body
mass variability and stability in active men
undergoing exercise-heat stress. International
journal of sport nutrition and exercise metab-
olism, 14, 532-540
22. Cheuvront, S. N., Carter, R., 3rd, Haymes, E.
M., & Sawka, M. N. (2006). No effect of
moderate hypohydration or hyperthermia on
anaerobic exercise performance. Medicine and
Science in Sports and Exercise, 38(6), 1093-
1097.
23. Coutts, A. J., Rampinini, E., Marcora, S. M.,
Castagna, C., & Impellizzeri, F. M. (2009).
Heart rate and blood lactate correlates of per-
ceived exertion during small-sided soccer
games. Journal of Science and Medicine in
Sport, 12(1), 79-84.
24. De Salles, B. F., Maior, A. S., Polito, M.,
Novaes, J., Alexander, J., Rhea, M., & Simão,
R. (2010). Influence of rest interval lengths on
hypotensive response after strength training
sessions performed by older men. The Journal
of Strength & Conditioning Research, 24(11),
3049-3054
25. Dirckx, J. H. (2001). The synthetic genitive in
medical eponyms: is it doomed to extinction.
Panace, 2(5), 15-24.
26. Galloway, S., & Maughan, R. J. (1997). Ef-
fects of ambient temperature on the capacity
to perform prolonged cycle exercise in man.
Medicine and Science in Sports and Exercise,
29(9), 1240-1249.
27. Gastin, P. B. (2001). Energy system interac-
tion and relative contribution during maximal
exercise. Sports Medicine, 31(10), 725-741.
28. Galvin, H. M., Cooke, K., Sumners, D. P.,
Mileva, K. N., & Bowtell, J. L. (2013). Re-
peated sprint training in normobaric hypox-
ia. British journal of sports medi-
cine, 47(Suppl 1), i74-i79.
29. Girard, O., Mendez-Villanueva, A., & Bishop,
D. (2011). Repeated-sprint ability - part I: fac-
tors contributing to fatigue. Sports Medicine,
41(8), 673-694.
30. Gonzalez-Alonso, J., Calbet, J. A., & Nielsen,
B. (1998). Muscle blood flow is reduced with
dehydration during prolonged exercise in hu-
mans. Journal of Physiology, 513(Pt 3), 895-
905.
31. Gonzalez-Alonso, J., Calbet, J. A., & Nielsen,
B. (1999). Metabolic and thermodynamic re-
sponses to dehydration-induced reductions in
muscle blood flow in exercising humans. The
Journal of Physiology, 520 (2), 577-589.
32. Gonzalez-Alonso, J., Mora-Rodriguez, R., &
Coyle, E. F. (2000). Stroke volume during ex-
ercise: interaction of environment and hydra-
tion. American Journal of Physiology- Heart
and Circulatory Physiology, 278(2), H321-
330.
33. Groepenhoff, H., Westerhof, N., Jacobs, W.,
Boonstra, A., Postmus, P. E., & Vonk-
Noordegraaf, A. (2010). Exercise stroke vol-
ume and heart rate response differ in right and
left heart failure. European Journal of Heart
Failure, 12(7), 716-720.
34. Guyton, A. C., & Hall, J. E. (2000). Textbook
of mecidal physiology. St. Louis:MO W. B.
Saunders Company.
35. Hammouda, O., Chtourou, H., Chahed, H.,
Ferchichi, S., Kallel, C., Miled, A., et al.
(2011). Diurnal Variations of Plasma
Homocysteine, Total Antioxidant Status, and
Biological Markers of Muscle Injury During
Repeated Sprint: Effect on Performance and
Muscle Fatigue-A Pilot Study. Chronobiology
International, 28(10), 958-967.
36. Heaps, C., Gonzalez-Alonso, J., & Coyle, E.
(1994). Hypohydration causes cardiovascular
drift without reducing blood volume. Interna-
tional Journal of Sports Medicine, 15(02), 74-
79.
37. Heydari, M., & Boutcher, S. H. (2013). Rating
of perceived exertion after 12 weeks of high
intensity, intermittent sprinting. Perceptual &
Motor Skills, 116(1), 340-351.
38. Hunter, G. R., Fisher, G., Bryan, D. R., &
Zuckerman, P. A. (2012). Weight loss and ex-
ercise training effect on oxygen uptake and
heart rate response to locomotion. Journal of
Strength and Conditioning Research, 26(5),
1366.
39. Ingebrigtsen, J., Bendiksen, M., Randers, M.
B., Castagna, C., Krustrup, P., & Holtermann,
A. (2012). Yo-Yo IR2 testing of elite and sub-
elite soccer players: Performance, heart rate
response and correlations to other interval
tests. Journal of Sports Sciences, 30(13),
1337-1345.
40. Judelson, D. A., Maresh, C. M., Farrell, M. J.,
Yamamoto, L. M., Armstrong, L. E., Kraem-
er, W. J., et al. (2007). Effect of hydration
state on strength, power, and resistance exer-
cise performance. Medicine and Science in
Sports and Exercise, 39(10), 1817-1824.
14
Raiza Sham Hamezah et al. Hydration status, sprint performance and physiological responses during repeated sprint ability (RSA)
41. Katz, A. (2001). Physiology of the Heart.
Philadelphia: USA: Wolters Kluwer Health.
42. Kraft, J. A., Green, J. M., Bishop, P. A., Rich-
ardson, M. T., Neggers, Y. H., & Leeper, J. D.
(2010). Impact of dehydration on a full body
resistance exercise protocol. European Jour-
nal of Applied Physiology, 109(2), 259-267.
43. Lane, R. D., McRae, K., Reiman, E. M.,
Chen, K., Ahern, G. L., & Thayer, J. F.
(2009). Neural correlates of heart rate varia-
bility during emotion. NeuroImage, 44(1),
213-222.
44. Lentner, C. (1981). Geigy scientific tables (8th
ed.). Delhi: Ciba-Geigy Limited.
45. McGarvey, J., Thompson, J., Hanna, C.,
Noakes, T. D., Stewart, J., & Speedy, D.
(2010). Sensitivity and specificity of clinical
signs for assessment of dehydration in endur-
ance athletes. British Journal of Sports Medi-
cine, 44(10), 716-719.
46. Maughan, R. J. (2003). Impact of mild dehy-
dration on wellness and on exercise perfor-
mance. European Journal of Clinical Nutri-
tion, 57, S19-S23.
47. Murray, B. (2007). Hydration and physical
performance. Journal of the American College
of Nutrition, 26(5 Suppl), 542S-548S.
48. G. Morris, J., Nevill, M. E., Lakomy, H. K.
A., Nicholas, C., & Williams, C. (1998). Ef-
fect of a hot environment on performance of
prolonged, intermittent, high-intensity shuttle
running. Journal of Sports Sciences, 16(7),
677-686.
49. Nybo, L., Sundstrup, E., Jakobsen, M. D.,
Mohr, M., Hornstrup, T., Simonsen, L., et al.
(2010). High-intensity training versus tradi-
tional exercise interventions for promoting
health. Medicine and Science in Sports and
Exercise, 42(10), 1951-1958.
50. Oppliger, R. A., & Bartok, C. (2002). Hydra-
tion testing of athletes. Sports Medicine,
32(15), 959-971.
51. Paoli, A., Pacelli, Q.F., Moro, T., Marcolin,
G., Neri, M., Battaglia, G., Sergi, G., Bolzetta,
F. & Bianco, A., 2013. Effects of high-
intensity circuit training, low-intensity circuit
training and endurance training on blood pres-
sure and lipoproteins in middle-aged over-
weight men. Lipids Health Dis, 12, 131
52. Pescatello, L. S., Fargo, A. E., Leach, C. N.,
& Scherzer, H. H. (1991). Short-term effect of
dynamic exercise on arterial blood pres-
sure. Circulation, 83(5), 1557-1561
53. Rakobowchuk, M., Harris, E., Taylor, A.,
Cubbon, R. M., & Birch, K. M. (2013). Mod-
erate and heavy metabolic stress interval train-
ing improve arterial stiffness and heart rate
dynamics in humans. European Journal of
Applied Physiology, 1-11.
54. Ross, D. L., & Neely, A. E. (1983). Textbook
of Urinalysis and Body Fluids: Appleton-
Century-Crofts Norwalk, CT.
55. Rynders, C., Angadi, S., Weltman, N.,
Gaesser, G., & Weltman, A. (2011). Oxygen
uptake and ratings of perceived exertion at the
lactate threshold and maximal fat oxidation
rate in untrained adults. European Journal of
Applied Physiology, 111(9), 2063-2068.
56. Sawka, M. N. (1992). Physiological conse-
quences of hypohydration: exercise perfor-
mance and thermoregulation. Medicine and
Science in Sports and Exercise, 24(6), 657.
57. Sawka, M. N., Burke, L. M., Eichner, E. R.,
Maughan, R. J., Montain, S. J., & Stachenfeld,
N. S. (2007). American College of Sports
Medicine position stand. Exercise and fluid
replacement. Medicine and Science in Sports
and Exercise, 39(2), 377-390.
58. Sawka, M. N., & Coyle, E. F. (1999). Influ-
ence of body water and blood volume on
thermoregulation and exercise performance in
the heat. Exercise Sport Science Review, 27,
167-218.
59. Shirreffs, S. M. (2000). Markers of hydration
status. Journal of Sports Medicine and Physi-
cal Fitness, 40(1), 80-84.
60. Shirreffs, S. M. (2009). Conference on "Mul-
tidisciplinary approaches to nutritional prob-
lems". Symposium on "Performance, exercise
and health". Hydration, fluids and perfor-
mance. Proceedings of the Nutrition Society,
68(1), 17-22.
61. Spencer, M., Bishop, D., Dawson, B., &
Goodman, C. (2005). Physiological and meta-
bolic responses of repeated-sprint activi-
ties. Sports Medicine, 35(12), 1025-1044.
62. Syme, A. N., Blanchard, B. E., Guidry, M. A.,
Taylor, A. W., VanHeest, J. L., Hasson, S., ...
& Pescatello, L. S. (2006). Peak systolic blood
pressure on a graded maximal exercise test
and the blood pressure response to an acute
bout of submaximal exercise. The American
Journal of Cardiology, 98(7), 938-943.
63. Thayer, J. F., Ahs, F., Fredrikson, M., Sollers
III, J. J., & Wager, T. D. (2012). A meta-
analysis of heart rate variability and neuroim-
aging studies: Implications for heart rate vari-
ability as a marker of stress and health. Neu-
roscience & Biobehavioral Reviews, 36(2),
747-756.
64. Thébault, N., Léger, L. A., & Passelergue, P.
(2011). Repeated-sprint ability and aerobic
fitness. The Journal of Strength & Condition-
ing Research, 25(10), 2857-2865
65. Tortora, G. J., Grabowski, S. R., Tortora, G.
J., & Roesh, B. (1996). Principles of Anatomy
and Physiology (8th ed.). Hoboken; NJ:
Wiley.
66. Vidal Andreato, L., Franzoi de Moraes, S. M.,
Del Conti Esteves, J. V., Regina de Araujo
Pereira, R., Lopes de Moraes Gomes, T., Vi-
dal Andreato, T., et al. (2012). Physiological
responses and rate of perceived exertion in
15
JPASPEX (2014) 2(2), 06-16
http://www.jpaspex.com e-ISSN 2289-5817
Brazilian jiu-jitsu athletes. Kineziologija,
44(2), 173-181.
67. Wadley, G., & Le Rossignol, P. (1998). The
relationship between repeated sprint ability
and the aerobic and anaerobic energy systems.
Journal of Science and Medicine in Sport,
1(2), 100-110.
68. Watson, G., Judelson, D. A., Armstrong, L.
E., Yeargin, S. W., Casa, D. J., & Maresh, C.
M. (2005). Influence of diuretic-induced de-
hydration on competitive sprint and power
performance. Medicine and Science in Sports
Exercise, 37(7), 1168-1174.
69. Williams, J. T., Pricher, M. P., & Halliwill, J.
R. (2005). Is postexercise hypotension related
to excess postexercise oxygen consumption
through changes in leg blood flow?. Journal
of Applied Physiology, 98(4), 1463-1468.
70. Yaicharoen, P., Wallman, K., Morton, A., &
Bishop, D. (2012). The effect of warm-up on
intermittent sprint performance and selected
thermoregulatory parameters. Journal of Sci-
ence and Medicine in Sport, 15(5), 451-456.
Raiza Sham Hamezah
Faculty of Sports Science & Coaching, Sultan Idris
Education University
Email: raiza.sham@yahoo.com
16
Article
Background: Although the effect of dehydration on performance is widely studied, limited data concerning the levels of risk training types pose to hydration status exists. This study sought to determine: (a) pre-training hydration status in adolescent sprinters relative to non-athletes, (b) changes in hydration markers across a season of adolescent sprinters relative to non-athletes, and (c) if frequency of training type explains unique variance in hydration. Methods: Hydration [via pre-training urine osmolality (UOsm) and thirst perception (TP)], daily water intake (TWI) [via 24-h food/fluid diaries] and frequencies of resistance, endurance and sprint training types (via training regime questionnaires) were assessed in 26 sprinters (age: 15.6±1.9 years) and 26 non-athletes (age: 16.0±1.6 years), during 4 mesocycles [general (T1) and specific (T2) preparation; pre-competitive (T3) and peaking (T4) phases], over 26 weeks. Results: Most athletes (62%-81%) and non-athletes (73%-92%) were underhydrated (UOsm>700 mOsmol/kg) pre-training across the season, despite a low TP. There were significant time (p =.042) and group (p =.006) effects, and a main group by time interaction for UOsm (p =.006) but not TP across the season, after controlling for TWI. Greater UOsm (in mOsmol/kg) were observed during T1 (906.3±250.1) and T2 (934.5±257.0) compared to T3 (852.1±268.8) and T4 (854.2±218.8). There was no significant change across the season for non-athletes. Frequencies of endurance training were positively associated with UOsm and explained unique variances across the season (R2 range from 7%-16%). Conclusions: Underhydration is high in the adolescent population. Training type may be related to the variations in hydration throughout a season, which may help to inform hydration practices of sprint athletes.
Article
Full-text available
In this study, the physiological responses and rate of perceived exertion in Brazilian jiu-jitsu fighters submitted to a combat simulation were investigated. Venous blood samples and heart rate were taken from twelve male Brazilian jiu-jitsu athletes (27.1±2.7 yrs, 75.4±8.8 kg, 174.9±4.4 cm, 9.2±2.4% fat), at rest, after a warm-up (ten minutes), immediately after the fight simulation (seven minutes) and after recovery (fourteen minutes). After the combat the rate of perceived exertion was collected. The combat of the Brazilian jiujitsu fighters did not change blood concentrations of glucose, triglycerides, total cholesterol, low density lipoprotein and very low density lipoprotein, ureia and ammonia. However, blood levels of high density lipoprotein were significantly higher post-fight (before: 43.0±6.9 mg/dL, after: 45.1±8.0 mg/dL) and stayed at high levels during the recovery period (43.6±8.1 mg/dL) compared to the rest values (40.0±6.6 mg/dL). The fight did not cause changes in the concentrations of the cell damage markers of creatine kinase, aspartate aminotransferase and creatinine. However, blood concentrations of the alanine aminotransferase (before: 16.1±7.1 U/L, after: 18.6±7.1 U/L) and lactate dehydrogenase (before: 491.5±177.6 U/L, after: 542.6±141.4 U/L) enzymes were elevated after the fight. Heart rate (before: 122±25 bpm, after: 165±17 bpm) and lactate (before: 2.5±1.2 mmol/L, after: 11.9±5.8 mmol/L) increased significantly with the completion of combat. Despite this, the athletes rated the fight as being light or somewhat hard (12±2). These results showed that muscle glycogen is not the only substrate used in Brazilian jiu-jitsu fights, since there are indications of activation of the glycolytic, lipolytic and proteolytic pathways. Furthermore, the athletes rated the combats as being light or somewhat hard although muscle damage markers were generated.
Article
Full-text available
Repeated sprint ability (RSA) is a critical success factor for intermittent sport performance. Repeated sprint training has been shown to improve RSA, we hypothesised that hypoxia would augment these training adaptations. Thirty male well-trained academy rugby union and rugby league players (18.4±1.5 years, 1.83±0.07 m, 88.1±8.9 kg) participated in this single-blind repeated sprint training study. Participants completed 12 sessions of repeated sprint training (10×6 s, 30 s recovery) over 4 weeks in either hypoxia (13% FiO2) or normoxia (21% FiO2). Pretraining and post-training, participants completed sports specific endurance and sprint field tests and a 10×6 s RSA test on a non-motorised treadmill while measuring speed, heart rate, capillary blood lactate, muscle and cerebral deoxygenation and respiratory measures. Yo-Yo Intermittent Recovery Level 1 test performance improved after RS training in both groups, but gains were significantly greater in the hypoxic (33±12%) than the normoxic group (14±10%, p<0.05). During the 10×6 s RS test there was a tendency for greater increases in oxygen consumption in the hypoxic group (hypoxic 6.9±9%, normoxic (−0.3±8.8%, p=0.06) and reductions in cerebral deoxygenation (% changes for both groups, p=0.09) after hypoxic than normoxic training. Twelve RS training sessions in hypoxia resulted in twofold greater improvements in capacity to perform repeated aerobic high intensity workout than an equivalent normoxic training. Performance gains are evident in the short term (4 weeks), a period similar to a preseason training block.
Article
Full-text available
This study aimed to assess total energy expenditure (TEE) and specific habitual physical activities in adolescent sprint athletes. Two methods used to estimate TEE, an activity diary (AD) and SenseWear armband (SWA), were compared. Sixteen athletes (6 girls, 10 boys, mean age 16.5 ± 1.6 yr) simultaneously wore a SWA and completed an AD and food diary during one week. Basal energy expenditure as given by the SWA when taken off was corrected for the appropriate MET value using the AD. TEE as estimated by the AD and SWA was comparable (3196 ± 590 kcal and 3012 ± 518 kcal, p = 0.113) without day-to-day variations in TEE and energy expended in activities of high intensity. Daily energy intake (2569 ± 508 kcal) did not match TEE according to both the AD and SWA (respectively p < 0.001 and p = 0.007). Athletes were in a supine position for a longer time on weekend days than on week days and slept longer on Sundays. Athletes reported a longer time of high-intensive physical activities in the AD than registered by the SWA on 4 out of 7 days. In addition to specific sprint activities on 3 to 7 days per week, 11 out of 16 athletes actively commuted to school where they participated in sports once or twice per week. The AD and the SWA are comparable in the estimation of TEE, which appears realistic and sustainable. The SWA offers an appropriate and objective method in the assessment of TEE, sleeping and resting in adolescent athletes on the condition that detailed information is given for the times the armband is not worn. The AD offers activity specific information but relies on the motivation, compliance and subjectivity of the individual, especially considering high-intensive intermittent training.
Article
Full-text available
The aim of this study was to determine the physiological effects of an high-intensity circuit training (HICT) on several cardiovascular disease risk factors in healthy, overweight middle-aged subjects, and to compare the effects of HICT to traditional endurance training (ET) and low-intensity circuit training (LICT). Fifty-eight participants (ages 61+/-3.3 yrs, BMI 29.8+/-0.9 ) were randomly assigned to one of the three exercise treatment groups: HICT, LICT and ET. The three groups exercised three times per week, 50 min per session for 12 weeks. Baseline and after intervention anthropometric characteristics: body weight (BW), fat mass (FM); blood pressure: diastolic (DBP) and systolic (SBP), blood parameters; CHOL-t (total cholesterol), LDL-C (low density lipoprotein-cholesterol), HDL-C (high density lipoprotein-cholesterol), TG (triglycerides), ApoB and ratio ApoB/ApoA1 were measured. Compared to other groups, HICT showed significantly higher reductions in FM, DBP, CHOLt, LDL-C, TG, ApoB and significantly greater increases in high density HDL-C. LICT resulted in the greatest reduction in SBP. All groups showed a significant improvement of BW without any significant differences between groups. Our findings indicate that high-intensity circuit training is more effective in improving blood pressure, lipoproteins and triglycerides than endurance training alone or lower intensity circuit training.
Article
This book gives an exposition of our current understanding of the biochemical and biophysical basis of heart function. Major emphasis is on the relationships between the biochemical properties of the individual constituents of the myocardial cell, the biophysics of heart-muscle function, performance of the intact heart, and the expression of these processes as abnormal contractile and electrical behaviour.
Article
The object of this study was to examine the effects of hydration status on exercise performance in a group of amateur athletes under conditions of hypohydration (HYPO) and euhydration (EUH) at 'neutrally stable' temperatures. Eight healthy, physically active, amateur University rugby players (age 21.0±1.4 yrs, BMI 28.3±6.1 kg/m2) underwent two 12 hr programs of hydration (fluid abstinence and consumption at ∼20 °C) in order to induce states of EUH and HYPO. The participants completed two 30 min cycle ergometer tests under each hydration state in a random order. Changes in performance were measured using heart rate (HR), rate of perceived exertion (RPE) and relative rate of oxygen uptake (VO2). Urine osmolality values (UOsm) were also measured to quantify hydration status. UOsm values were EUH 385±184 mOsm/kg and HYPO 815±110 mOsm/kg. In the EUH condition, from rest to 30 min, HR values ranged from 78±12 to 116±12 beats/min, RPE 6±0 to 11±2 units and VO2 5.7±2.1 to 16.8±3.4 mL/kg/min. In the HYPO condition, HR 85±9 to 124±13 beats/min, RPE 6±0 to 13±2 units and VO2 6.2±2.8 to 20.1±3.5 ml/kg/min (mean±SD, p≤0.05). In conclusion, HR, RPE and VO2 variables increased significantly under HYPO conditions when compared to EUH conditions at ∼20°C and therefore having a detrimental effect on performance.
Article
Objectives: To investigate the effect of various warm-up intensities based upon individual lactate thresholds on subsequent intermittent sprint performance, as well as to determine which temperature (muscle; T mu , rectal; T re or body; T b) best correlated with performance (total work, work and power output of the first sprint, and % work decrement). Design: Nine male team-sport participants performed five 10-min warm-up protocols consisting of different exercise intensities on five separate occasions, separated by a week. Methods: Each warm-up protocol was followed by a 6 × 4-s intermittent sprint test performed on a cycle ergometer with 21-s of recovery between sprints. T mu , T re and T b were monitored throughout the test. Results: There were no differences between warm-up conditions for total work (J kg −1 ; P = 0.442), first sprint work (J kg −1 ; P = 0.769), power output of the first sprint (W kg −1 ; P = 0.189), or % work decrement (P = 0.136), respectively. Moderate to large effect sizes (>0.5; Cohen's d) suggested a tendency for improvement in every performance variable assessed following a warm-up performed at an intensity midway between lactate inflection and lactate threshold. While T mu , T re , T b , heart rate, ratings of perceived exertion and plasma lactate increased significantly during the exercise protocols (P < 0.05), there were no significant correlations between T mu , T re , and T b assessed immediately after each warm-up condition and any performance variable assessed. Conclusions: Warm-up performed at an intensity midway between lactate inflection and lactate threshold resulted in optimal intermittent sprint performance. Significant increases in T mu , T re and T b during the sprint test did not affect exercise performance between warm-up conditions.
Article
The effect of a 12-week high-intensity intermittent exercise (HIIE) intervention on the rating of perceived exertion (RPE) response of young males was examined. Participants (N = 38; M BMI = 28.7 kg x m(-2), SD = 3.1; M age = 24.9 yr., SD = 4.3) were randomly assigned to either an exercise or control group. The exercise group received HIIE three times per week, 20 min. per session, for 12 weeks. RPE was assessed before and after HIIE training and during pre- and post-maximal oxygen uptake (VO2 max) testing. After HIIE training, RPE was significantly higher in Weeks 11-12 compared to Weeks 1-2. In contrast, heart rate was similar throughout training. Comparing post- to pre-VO2 max test, RPE was significantly lower in the exercise group, whereas for controls, RPE was similar. Aerobic power improved 15% for the exercise group, with no significant change for controls. HIIE resulted in significant increases in RPE, whereas RPE during the VO2 max test was significantly decreased.