Physical Training Apr 2006
 
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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


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 28o 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 28o 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 26o to 38o (Μ=33.58o) Celsius grades (sd=2.8) and the relative humidity from 42% to 75% (Μ=56.04%) (sd=8.7).

table 2


table 3

 
figure 1
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 35o 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.

References




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Physical Training Apr 2006