Common practices of beach
volleyball players regarding fluid, supplements and nutrition intake
during a tournament
Dr E. Zetou, Z. Vernadaki, F.
Mountaki*, G. Giatsis*, & K. Laparidis
Department of Physical Education and Sport Sciences, Democritus
University of Thrace, Komotini
*Department of Physical Education and Sport Sciences, Aristotle
University of Thessaloniki, Thessaloniki
Correspondence: Dr Eleni Zetou,
Department of Physical Education and
Sport Sciences,
Democritus University of Thrace, 69100 Komotini,
Greece.
Tel: 030 6945773762.
E-mail: elzet@phyed.duth.gr
ABSTRACT
The aim of this study was to
record the common practice of beach
volleyball players in regards to fluid, supplements and nutrition
intake during a tournament. During the three days, tournament data was
collected for male players (n=47, 21 elite and 26 non elite), age
Μ=26.17 (sd=5.12) years old, weight Μ=83.10 k. (sd=6.9) and height Μ=1.
89 m (sd=5.79). The athletes responded to a questionnaire that was
specially developed for this purpose and that had formerly been tested
for its internal validity and reliability. The questionnaire was
completed by the athletes after their games had ended so as to not
disturb them prior to the game. In the framework of this questionnaire,
the athletes answered whether they had drunk fluids one hour before the
game, whether they had drunk solutions, whether they had eaten and
exactly what, whether they took vitamins or other elements. During the
tournament, a total of 50 games took place with the athletes playing 3
games per day with each game lasting for 42.2 minutes on average. Air
temperature and humidity were measured in each day of the tournament,
at the beginning and at the end of every game and ranged from 26o
to
38o C (Μ=33.58o C, sd=2.8) and 42% to 75%
(Μ=56.04%, sd=8.7)
respectively. The analysis of variance did not display differences
between the elite and non elite athletes in their common practice
regarding the intake of fluids, supplements or nutrition during the
tournament. The results show that the athletes were not aware of the
importance of consuming fluids, solutions and proper nutrition prior to
their games. It is suggested that athletes be made aware of the
important role that fluids and proper nutrition play regarding their
performance and that they should intake greater quantities of fluids in
order to
prevent dehydration, which can lead to the loss of vital elements and
thus to a declining performance.
Key words: fluid intake, nutrition, common practice, dehydration,
performance, beach volleyball
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Introduction
Other than the limits imposed by heredity and training, diet is
the single most important factor influencing athletic performance
(Costill, 1986). Proper nutrition helps to optimize energy production,
control, and efficiency for sport. In addition, inappropriate nutrition
may contribute to sports injuries (Brouns, Saris, & Hoor, 1986;
Eichner, 1995), an effect more serious in highly trained athletes than
in recreational athletes (Chen, Wang, Li, Zhao, Wang, Jiao, & Hou,
1989).
During the past few years an increasing number of studies provide
evidence of the relationship between proper nutrition and sporting
action, in all kinds of sports that are characterized by a prolonged
continuous action (Berstrom, Hermansen, Hultman, & Saltin, 1967;
Gonzalez-Alonso, Mora-Rodriguez, Below, & Coyle, 1997; Wong, &
Williams, 2000; Ivy, Goforth, Damon, McCauley, Pearsons, & Price,
2002; Natsis & Geladas, 2002b; Coyle, 2004), but also in sports
that are characterized by intermittent action (Bangsbo, Norregaad,
& Thorsoe, 1992; Nicholas, Williams, Lakomy, Phillips, &
Nowitz, 1995; Nicholas, Green, Hawkins, & Williams, 1997; Nassis,
Chisnall, & Williams, 1998; McGregor, Nicholas, Lakomy, &
Williams, 1999; Nicholas, Tsinzas, Boobis, & Williams, 1999).
Fatigue, and thus the impaired capacity of the athletes to produce
muscular output, or the lack of concentration towards the target, for
most sports, is associated with the energy reserves of the body and its
level of hydration. The environmental conditions determine which of
these two significant factors will lead to fatigue. (Gallow, &
Maughan, 1997; Morris, Nevill, & Williams, 2000). When training and
particularly when the game takes place under a cold or a neutral (in
terms of temperature) environment, meaning a temperature of less than 28
o
C, fatigue is mainly related to the carbohydrate reserves in the body
(mainly hepatic and muscle glycogen). When the muscular exercise takes
place in a warm environment, under a temperature greater than 28
o
C, fatigue is related to a greater extent to dehydration, meaning the
decrease in the level of fluids in the body due to perspiration and
hyperthermia (Gallow, & Maughan, 1997; Parkin, 1999; Morris, et
al., 2000; Drust, Rasmussen, Mohr, Nielsen, & Nybo, 2005).
However, under both conditions, whether the exercise is carried out in
a warm or mildly warm environment, nutrition significantly contributes
to maximizing the performance of the athletes. (ACSM, 2000; Coyle,
2004).
Dehydration, a common practice among competitive athletes in sports
including Beach Volleyball, has uncertain effects on athletes’
performance, impairments to muscular endurance, cognitive functioning,
thermoregulation and gastric emptying (Copinathan, 1988; Buskirk, &
Puhl, 1989; Sawka, & Pandolf, 1990).
During prolonged exercise the intake of appropriate fluids will improve
performance, this being applicable not only to elite athletes but to
all people involved in sports and physical activities. Rehydration
following the exercise is also particularly important for the recovery
and restoration of physical and mental performance.
Beach volleyball is an exciting, spectacular sport which is played
under demanding enviromental conditions. Furthermore, as only two
players can participate in beach volleyball, the players are forced to
perform continuous actions under high temperatures and high humidity
for many hours, since the game is structured in such a way that they
need to play up to three games per day with small intervals between
them and for three days in a row.
Beach volleyball, like indoor volleyball, requires activities with
short duration and extremely high power output (Scates & Linn,
2003). In addition, moving on sand increases energy utilization
compared to moving on solid ground (Zamparo, Perini, Orizio, Sacher,
& Ferretti, 1992; Lejeune, Willems, & Heglund, 1998). The heart
rate often reaches very high levels. These characteristics make beach
volleyball a sport with increasing demands for anaerobic and aerobic
capacity (Ferretti and Zeppill, 1987).
The long duration of exposure of the players to the sun and to high
temperatures are very important factors that increase the risks of
dehydration and thermal stress. Dehydration coupled with the loss
in body weight due to perspiration, leads to the loss of vital
elements, which play a decisive role and thus, dehydration affects the
performance of the athletes not only in terms of muscular endurance and
cognitive functioning but also of thermoregulation. There is a need to
maintain a balance between the intake and loss of fluids so that the
performance of players will not be adversely affected.
The requirements in maintaining the appropriate balance of health and
athletic performance are based on the proper selection of nutrition,
fluids and aids and also on the appropriate timing of their intake. In
particular, this goal is achieved by consuming a great variety of
nutrition from the food chain, with a balanced intake of energy in
relation to our needs in order to reach the ideal body weight level,
while ensuring the proper intake of fluids for the appropriate
hydration and electrolyte balance, with the appropriate timing of food
and fluids intake in relation to the duration of training and the game,
and with the seeking of advice by experts regarding the intake of food
supplements and ergogenic aids.
During the 1960s doctor Robert Cade of the University of Florida, first
developed a drinkable solution that replenished certain substances
which are lost due to perspiration during intense exercise. Since then
a great number of similar concoctions were introduced and they
consisted of solutions of glucose-electrolytes or polymeric-glucose.
Their main components are water, carbohydrates (in the form of fructose
or dextrose) and electrolytes (sodium, chlorine, potassium,
phosphorus).
Deriving from studies that were carried out when providing solutions
with water under conditions of a prolonged high intensity exercise,
researchers reached positive conclusions as regards the performance of
the athletes. Researchers claim that advanced performance is attributed
to: a) maintaining the level of glucose in the blood (Coyle, et al.,
1986), b) in saving muscle glycogen (Nicholas, et al., 1999) and c) on
the possible effect of carbohydrates on the central nerve system of the
athletes (Welsh, Davis, Burke, & Williams, 2002; Nybo, 2003;
Winnick, Davis, Welsh, Carmichael, Murphy, & Blackmon, 2005).
Beach volleyball is a physically demanding sport, involving prolonged,
high intensity exercise under hot temperatures and humid environmental
conditions. Nutrition, vitamins, amino-acids, proteins, carbonate,
fluid intake, energy drinks and supplements play a key role in
influencing playing performance. The purpose of this study was to
record beach volleyball players’ common practice in regards to their
nutrition, fluid and supplements intake during a tournament.
Method
Participants
Participants to this study were 47 beach volleyball players, who
competed in an official tournament, with average values regarding: age
Μ=26.17 years old (sd=5.12), weight Μ=83.10 kilos (sd=6.9), Μ=1. 89 m.
(sd=5.79), height and body fat (skinfolds) M=11.7 (sd=3.4).
Participants were divided into an elite (n=21) and a non elite group
(n=26). Elite athletes were players who had training experience of 8-10
years and competed in international tournaments while non elite players
were those who had training experience less than 8 years and competed
in national tournaments. One day before the tournament started, the
percentage of body fat was measured by means of skin folds at the
positions suggested by bibliographical sources and the average value
was recorded. The median time of players training in playing and in
preparation period was for non elite athletes 2.41 hours (sd=.67) per
day, and 2.86 hours (sd=1.17) per day for elite athletes. All
participants consented prior to their participation and were free to
withdraw from the survey at any time. The study was approved by the
Ethics Committee of the Greek Sports Commission.
Measurement tool
The questionnaire was especially developed in order to examine the
common practice of players as regards to the intake of food and fluids
during the tournament and had been formerly examined for its internal
validity and reliability. The questions comprising the questionnaire
where developed by a nutrition expert together with a beach volleyball
expert. The questionnaire was distributed at a previous tournament in
order to ascertain whether the questions were understood by the
players. The questionnaire consists of 13 questions (Table 1), with
possible answers either “no” or “yes” and if the answer was “yes”, the
players further noted down the type and dosage of the product or the
moment in time in which it was consumed. The questionnaire was
completed by the athletes following the end of their games so as to not
disturb them prior to the game.
Finally, air temperature and humidity (Vaisala HM34, Humidity and
Temperature Meter, Finland) were also measured in each day of the
tournament, at the beginning and at the end of every game.
Questionnaire
Table 1: The questions which comprise the questionnaire
Questions
1. Do you take vitamins? Yes No
If you do take, name them
2. Do you take microelements? Yes
No
If you do take, name them
3. Do you take a supplement of proteins?
Yes No
If you do take, name them
4. Do you take amino acids? Yes No
If you do take, name them
5. Do you take a nutrition supplement?
Yes No
If you do take, name them
6. Are you currently following a special diet?
Yes No
If you are, describe it
7. How often do you weight yourself? Every
day Every week Every
month Other
8. Do you know a way in which to control fluid
balance? Yes No
If you do, describe it
9. Do you use a plan for fluid intake during training or
competition? Yes No
If you did, what did you drink?
When you drink, how much do you drink? How often do
you drink?
10. Is there any nutrition, which you avoid consuming before match
because you believe that it harm you
Yes No
If there is, mention it
11. Mention food, fluids or supplements which you consume in between
games during competition.
when, food, fluid, supplement
12. Do you keep guidance for fluid ingestion which you drink after the
game?
Yes No
13. Do you have adequate information about the association between
dehydration and performance?
Results
Factor and reliability analysis of questionnaire
In order to examine the constructional validity of the
questionnaire, an investigatory factorial analysis was carried out. A
factor emerged from the analysis that explicated 63% of variability.
Furthermore, the examination of internal coherence provided the a of
Cronbach at a value of .781 (a=.781). The findings displayed that the
questionnaire contained the expected factorial construction and
satisfactory internal coherence.
Physical characteristics of beach volleyball players are presented in
table 2. A summary of the duration of matches and environmental
conditions is presented in table 3. In total, 50 games took place, 36
of which ended with a score of 2-0 and only 14 of them with a score of
2-1. The average duration of the games was 42 minutes (sd=9.8) each. On
average players played 3 games per day and lost 587.23 (sd=593.3) grams
of weight per game, while receiving per game on average an intake of
730.64 (sd=393.29) grams of fluids, water in preference, besides 7
persons who consumed solutions Μ=164.04 grams (sd=236.13) (Gatorade,
Lucozate eg).
The temperature during the games ranged from 26
o to 38
o
(Μ=33.58
o) Celsius grades (sd=2.8) and the relative humidity
from 42% to 75% (Μ=56.04%) (sd=8.7).
Figure 1: Distribution of percentages
of “yes” and “no” answers to every question.
Differences between elite and non elite athletes
An independent samples t-test was conducted to compare the
common practice in nutrition and fluid intakes of elite and non elite
athletes during the course of a tournament. There was no significant
difference in scores in any of the questions. There was
significant difference (t(45)= -2.500, p=0.21) only in the question
«whether they had taken trace elements», where the elite
athletes (M=1.24, SD=0.44) responded affirmatively in
comparison to the non elite athletes (M=1, SD=0.00) . The
magnitude of the differences in the means was found to be very large
(eta squared=0.99).
Discussion
The advantage of the present study is that it took place in real
time conditions during an official tournament. The results derived from
this study provided information on the common practice of players in
regards to their nutrition before and after their games, but also
regarding the intake of fluids, solutions, vitamins and other ergogenic
aids. The answers of the athletes to most of the questions were
negative. Very few players took solutions, vitamins, trace elements or
other aids and those who did were elite athletes. Most of the athletes
did not follow a systematic diet before their games, relying on their
own personal experiences they simply refrained from consuming certain
food that might trouble them. They did not measure their body weight
often and most important they were not aware of the association between
dehydration and performance, neither how to maintain the balance of
fluids in their body nor did they have some plan concerning the intake
of fluids during their games.
Beach volleyball players are forced to perform continuous actions under
high temperatures and high humidity for many hours, since the game is
structured in such a way that they may need to play three games per day
with small intervals between them and for three days in a row. Beach
Volleyball requires activities with short duration and extremely high
power output (Scates & Linn, 2003). In addition, moving on sand
increases energy utilization compared to moving on solid ground
(Zamparo, Perini, Orizio, Sacher, & Ferretti, 1992; Lejeune,
Willems, & Heglund, 1998). These characteristics make beach
volleyball a sport which places increasing demands on the heart rate
and requires high level anaerobic and aerobic capacity (Ferretti, &
Zeppill, 1987). These characteristics of the game require great energy
reserves, which the players must acquire from the food and the
solutions they consume during their games.
Due to the high temperatures that can reach up to 35
o C and
the high level of humidity (up to 75%) during the games, the control
over the balance of the body fluids is a crucial factor in avoiding
dehydration from taking place with its subsequent effects as well as
the risk of thermal stress (ACSM, 1995).
Cognitive performance, which is an important aspect of games, such as
beach volleyball, may also be impaired when dehydration and
hyperthermia are present, but there is limited information available.
The effect that dehydration had on cognitive performance was not
evaluated in this study. Copinathan, Pichan, and Sharma, (1988) showed
in a variety of tests of cognitive function, that performance was
adversely affected when the level of dehydration, which was induced by
exercise in the heat, reached 2% of the initial body weight.
Opportunities for fluid intake during the game are limited and this,
coupled with the fact that the ingested fluid from the stomach may not
be readily absorbed in the small intestine, makes it appropriate for
players to ensure they are fully hydrated before beginning their match
play. These players were due to play again in the same day after a
recovery time period of only 2 or 3 hours, so it seems unlikely that
those who had experienced the largest fluid deficits would have fully
replaced them before resuming play. The possible cumulative effects of
playing a number of matches under hot weather with incomplete
restoration of fluid balance must give rise to some concerns.
In the field of beach volleyball there are no similar studies with
which to compare the results of the present study, neither applicable
to training conditions nor to real time game conditions.
It is suggested that coaches inform their athletes about the effects of
appropriate nutrition and hydration during their games, in order to
avoid the risk of dehydration. In addition, it is suggested that
athletes should be informed regarding the intake of proper aids, such
as carbohydrated fluids (Gatorade, Powerade etc.) which have been shown
to facilitate athletes in sustaining their performance.
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