Knowledge and Use of Dietary Supplement Products by Deaf Athletes

The purpose of this study was to determine the knowledge and use of dietary supplement products (DSP) among the deaf athletes of the Turkish Deaf Sports Federation. A total 74 voluntary athletes from various sports, 11 female and 63 male athletes (Mage=23.62±5.38 years) participated in this study. The data was collected through the survey method and was analyzed by Fischer Exact test, frequencies and percentage distribution. As a result, it has been determined that 39.2% of deaf athletes have knowledge about DSP and athlete diets; their rate of DSP use increases as their educational level increases; the rate of DSP use in national athletes is higher and that taekwondo athletes do not use DSP while a rate of at least 30.8% DSP use is evident in other branches. In addition, the findings show that the deaf athletes do not have sufficient knowledge about their DSP use and they have problems in accessing reliable information about this issue.


Introduction
Genetic structure, suitable exercise and balanced diets are the primary factors which affect the performance of athletes. As athletes' performance can be enhanced through a balanced diet, it can ve negatively affected through an unbalanced diet (Fox, Bowers, & Foss, 1999). Athletes spend great effort for a higher performance and spend a majority of their time and energy on exercise, however they cannot get full benefit from their efforts due to diets which are not suitable for them, cause an adverse effect or sometimes harm them (Ersoy, 2014;Katch, Katch, & Mcardle, 1994). Cupisti et al. (2002) have found out that a proper and balanced diet is important for the athletes in many ways. Many conditions which affect athletes directly or indirectly such as increasing the performance, preventing weight loss and excessive weight gain, preventing illnesses caused by the electrolyte loss in the body, proper functioning of the digestive system and renewal of sources of energy in the recovery period, can be made possible through a proper diet.
Diets are regarded as one of the most important factors which the athletes can control when they have knowledge about them and affect their performance (Turgut et al., 2015). Therefore, athletes need to have sufficient knowledge about diets in order to be able to improve their performance and obtain successful results (Süel et al., 2009). Athletes who regularly exercise and participate in competitions need more knowledge about diets and correct diet programs compared to people who exercise for leisure and health (Özdemir & Ersoy, 2009). However, it is considered that many people who participate in sports do not have sufficient information about balanced diets and that erroneous applications are common among athletes and can create dangerous results (Süel et al., 2006). use of DSP by people with disabilities is quite limited (Özdemir & Ersoy, 2009;Crossland & Broad, 2011) and research on deaf individuals has not come to the fore among these limited studies. Crosland and Broad (2011) have stated the difficulties experienced in reaching out to sufficient number of individuals/athletes for scientific studies on this subject.
For instance, it is suggested for sports dieticians to advise athletes with disabilities who actively engage in sports in terms of sufficient and balanced diets, the effect of diets on performance, the importance of fluid consumption and ergogenic support (Özdemir & Ersoy, 2009). In addition, the critical evaluation of the validity of what is suggested about the importance of a proper diet and special diets with dietary supplement products requires expertise and the appropriate points of views (McArdle et al., 2010). Despite the importance of diets, it is known that there is lack of information on this subject (Özdemir, 2009).
It is noteworthy that there is a limited number of studies on diets and DPS applications which have significant effects on performance in an environment in which the number of competitions and activities where disabled and deaf individuals can compete and disabled sports are becoming more competitive (Crosland & Broad 2011), as well as general health Crosland andBroad 2011, Özdemir &Ersoy, 2009). There are no studies in related literature in which the knowledge level of deaf athletes regarding DPS has been analyzed.
The primary goal in the evaluation of diets of disabled athletes is to define the consumption of the individual, know the mistakes he is doing and design the most suitable diet plan by suggesting the required changes. In the light of the information to be obtained, negative consequences arising from the insensible use of dietary supplement products can be prevented.
The purpose of the study is to determine the use of dietary supplement products by hearing handicapped athletes and their knowledge on the issue and to analyze whether there is a relationship between their educational level, sports branch, being a national team athlete, monthly average income level, money allocated for their diets and the use of dietary supplement products.

Participant (Subject) Characteristics
Deaf athletes (N=73) with the age average of 23.625.38 years, height average of 180.308.28 cm and body weight average of 74.7012.76 kg have participated voluntarily in the study in the Turkish national team camp (Table 1), 11 of whom were female and 63 of whom were male from 6 different branches, being basketball, volleyball, handball, taekwondo, swimming and track and field. The athletes were given a survey with the purpose of determining their use of dietary supplement products and their knowledge levels about these products. The regulations state that at least 55 dB hearing loss in better ear according to the rules of the International Committee of Sports for the Deaf (ICSD) and Deaflympics-Games and in audiological terms, have participated in the study. Prior to the study, approval has been received from Kırıkkale University, Clinical Researches Ethics Committee (Decision No: 11/10, Date: 19/04/2016).

Data Collection Tool
The participants were given the survey form consisting of multiple choice questions and open ended questions. The survey consisted of 38 questions in 3 parts, on general knowledge, information about dietary supplement products, and athletes' knowledge on their use and athlete diets.
The survey was prepared by experts on the subject (Ünsal, Özdemir, & Ersoy, 2010;Yarar, et al., 2011) and used in this study with their permission.
Prior to the survey, the translator who knows Turkish Sign Language (TSL) carried out pre-studies together with volunteering deaf participants whose primary language is TSL and have active communication with the deaf community in Turkey with the purpose of calculating the possible equivalent of each statement in the survey from in TSL and to present a more accurate translation.
The surveys were distributed to deaf athletes who volunteered to participate in the study after the purpose of the study was indicated. The participants preferred access in TSL, since they frequently use sign language and translators. The surveys were translated by the TSL translator and given using sign language through the face to face survey method.

Statistical Analysis
The statistical analysis related to the study was carried out by the SPSS 19 package program and the significance value has been determined as 0.05. The average, median and standard variation values and frequency-percentage distributions of the personal characteristics of the athletes were turned tabulated with the use of descriptive statistics. For the only sample which tests whether an individual or objects displays a significant difference according to the levels of a categorical variable, the Chi-Square test was used. Actually, the test analyzes the significance of the difference between the numbers observed in each category of the variable and the numbers expected for the categories (Büyüköztürk, 2014). The answers given to the questions in the survey with the purpose of determining the dietary supplement products and their usage status were tabulated for frequency and percentage values according to various variables. The intergroup percentile distribution relationship of the given answers were determined with the Fischer Exact test and indicated in tables. In the study carried out with the purpose of determining the use of dietary supplement products by hearing impaired athletes whose age average was 23.625.38 years and their knowledge levels about these products, it has been seen that 27% of the participants were primary, 62.2% were high school and 10.8% were university graduate athletes. In addition, it has been determined that 79.7% were national team athletes and 20.3% had attended the national team camp for the first time. When they were evaluated according to the distribution in sports branches, it was seen that the most participation was in the basketball branch (21.6%). It was determined that 58.1% of the participants were students; most of them lived with their families )87.8%); in 58.1% the monthly wage of the families were below 2000 TL and 59.5% could allocate less than an average of 200TL monthly for their diets (Table 2). When we take a look at Table 3, it is possible to see that 68.9% of the participants did not use any dietary supplement products and that 90% of those who used these products bought them from stores. It can be seen that only 39.2% are knowledgeable about dietary supplement products and athlete diets. 60% of those who had knowledge about dietary supplement products and athlete diets stated that they received information from their coaches. While 56.5% of the athletes who used dietary supplement products stated that their purpose was to increase performance, 69.6% stated that they have seen these products' benefits. 2.8 57.5% of the participants of the study stated that there is a very close relationship between diets in sports and success; 23.3% stated that there is no relationship between diets and success, 19.2% stated that they had no knowledge about this issue (Table 4) and 90.3% stated that they did not feel the need to go on a diet (Table 5).

Results
When we take a look at Table 6, it can be seen that 65.3% of the participants stated that they had 3 meals per day; almost half of the participants (45.9%) stated that they skipped lunch and 35.2% stated that they skipped meals since they did not have enough time. 41.7% of the athletes stated that they drank 3-4 liters of fluids per day and 90.3% stated that they had fluids while doing sports, 80.6% stated that they had fluids during exercise and exercise breaks and 54.3% stated that they had fluids after exercise. 49.3% of the athletes who had a meal before exercise (54.2%) stated that it was rich in proteins, while 23.9% stated that it was rich in protein and carbohydrates.  Table 7, a majority of the participants of the study (70.2%) preferred honey and molasses as the nutrients which affect performance.
When the questions and answers to DSP, their effects and use are analyzed, it can be seen that 81.4% of the participants stated that it is absolutely necessary to use additional vitamins and minerals and that vitamins gave energy to the body; 57.7% stated that additional proteins should be used to increase muscle volume and 52.2% stated that all herbal products are harmless (Table 8). When we take a look at Table 9, it can be stated that there is a relationship between educational status and use of dietary supplement products according to the results of the Chi square test ( 2 =3.31) (p<0.05). When the frequencies are analyzed, it is seen that the rate of using dietary supplement products increases as the educational level increases. While the rate using dietary supplement products is 15% in primary school graduates, it is 37.5% in university graduates. As it can be seen in  As it can be seen from Table 13, according to the results of the Fischer Exact test, it can be stated that there is a relationship between sports branches and the usage of dietary supplement products ( 2 =0.46; p<0.05). When the frequencies are analyzed, it is seen that, in particular taekwondo athletes do not use dietary supplement products, whereas in other branches there is a minimum rate of 30.8% and a maximum of 50% usage of supplementary products.

Discussion
It has been seen that 39.2% of the participants of the study, which analyzes the use of dietary supplement products by deaf athletes and their knowledge levels about these products, have knowledge about these products ( In our study, 60% of the individuals who have knowledge about dietary supplement products and athlete diets have stated that they have received information from their coaches, 30% from their classes and 10% from newspapers and magazines (Table 3). In Süel et al.'s study (2006) on basketball players (61.9%), the findings are in parallel with the findings of our study. In studies on top level athletes who have no deaf and participate in different individual sports branches (Şenel et al., 2004;Yarar et al., 2011), amateur basketball players (Yıldırım et al., 2005), amateur football players (Göral et al., 2010) and female basketball players (Pulur and Cicioğlu, 2001), it has been determined that the number of athletes who receive information from their coaches about DSP is lower. In a study carried out by Yarar et al. (2011) on the knowledge and habits of elite level athletes with no hearing problems, it was found that while 96.1% of the athletes thought that there is a relationship between sports diets and success, according to the findings of our study, 57.5% of the deaf athletes stated that they think that there is a very close relationship between sports diets and success. According to Ersoy (1986), most of the coaches are now knowledgeable about athlete diets and DSP. Therefore, it is difficult to say that athletes have accurate information about athlete diets.
When studies on athletes with no hearing problems (Yarar et al., 2011;Göral et al., 2010) are compared with studies on deaf athletes, it has been seen that the use of DSP in deaf athletes was lower (31.1%) ( Table 3). In addition, it can be seen that as the level of education increases, the use of supplementary products increases as well. While the rate of using dietary supplement products in primary school graduates is 15%, this rate has been determined to be 37.5% in university graduates (Table 9). In Şenel et al.'s (2004) study on the top level athletes in different individual sports branches, the rates of using dietary supplement products according to educational level have been determined as 81.7% university, 15% high-school, 1.7% as primary school, 0.8+ post-graduate and 0.8% doctorate graduates.
The purpose of 56.5% of those who use dietary supplement products (n=13) is to increase performance, 30.5% (n=7) to increase muscle mass, 13% (n=3) vitality. 69.6% of those who use dietary supplement products (n=16) stated that they benefitted from the products ( Table 3).
As it can be seen Table 10, according to the findings of our study, there is a relationship between being a national athlete and using dietary supplement products (p<0.05). This study displays similarities with the results of Akıl and Gürbüz's (2005) study, in which they analyze the effects of the knowledge level of athletes in the throwing branches (marathon and shot put) of athletics on diets. It has been seen that national athletes have a higher rate of using dietary supplement products.
90% of individuals who use DSP buy their products from stores. Although Crosland and Broad (2011) find the DSP needs of "deaf, visually impaired or cognitively impaired' athletes similar to other individuals, they state that shopping, accessing food facilities, financial difficulties (feeding difficulties) and social activities are effective on the types of food involved in the daily diet and the amount of energy used and spent daily. According to the findings of our study, it was seen that there is no relationship between the amount of money allocated by deaf athletes for their diets and their use of dietary supplement products (p>0.05) and that there is a relationship between their branches and use of dietary supplement products (p<0.05).
To the question related to the number of meals they have per day, most of the deaf athletes have replied three meals (65.3%) (  Pulur and Cicioğlu's (2001) study on female basketball players, participants stated 3 meals by 43%, 2 meals by 32% and 4 meals by 25%. 45.9% of the participants stated that they ship lunches, 23% breakfast and snacks and 8.2% diner. In Turgut et al.'s (2014) study on swimmers, participants stated that they skipped breakfast by 52.04% and lunch by 41.83%. 29.6% of the participants in the study stated that they skip meals due to not having appetite, 22.2% due to controlling their body weight, 35.2% due to not having enough time for meals, 7.4% due to choosing meals and 5.6% due to financial difficulties.
Previous studies have shown that the number of meals and their timings affect physical performance. It is considered that athletes who have 5 meals a day display a better performance compared to athletes who have 3 meals a day and that their total exercise productivity increases with 5 meals. It is considered that the athletes' distributing their daily energy intake into 5 meals a day in a balanced manner has a positive effect on their performance. By consuming food in this manner, it has been seen that stability in the athletes' blood sugar levels and saturation in their muscle glycogen stores could be achieved (Eskici, 2015).
Consuming a balanced diet which is sufficient in terms of quality and amount is quite effective prior to, during and after exercise to increase performance to the maximum level. For instance, the most suitable timing is having the last meal 3-4 hours prior to exercise and not exercising on an empty and full stomach (Sağlam, 1993). In this study, the deaf athletes answered the question on how many hours before exercise they eat as 2 hours earlier by 54.2% and 3-4 hours by 38.9%). The findings of Yarar et al.'s (2011) study on the knowledge and habits of elite level athletes on diets and Yıldırım et al.'s (2005) study on amateur basketball players are in parallel with the findings of our study. Since athletes' digestion needs to be easy, they need to eat 3 to 4 hours prior to competitions and consume food which is rich in carbohydrates and low in protein and fat (Fink et al., 2017).
Deaf athletes (49.3%) have stated that prior to exercise, they have a diet which primarily consists of protein, 23.9% have stated it consists of both protein and carbohydrates and 18.3% have stated that they do not change their diets prior to exercise or competitions (Table 6).
In Yarar et al.'s study (2011) on the knowledge and habits of elite level athletes on diets, while the athletes stated that they did not make any changes in their eating habits prior to exercise and competitions, 26% stated that they have protein and carbohydrate rich meals and 25.4% have carbohydrate rich meals.
The deaf athletes stated that they drink water after exercise by 54.3%, have carbohydrate rich meals by 12.9%, eat fruit by 11.4% and drink fruit juice by 10%. In Yarar et al. (2011) study on the knowledge and habits of elite level athletes on diets, 27.8% of the athletes stated they do not make any changes in their diets, 27.8% stated that they have carbohydrate rich meals. However, having carbohydrate rich food prior to exercise and competitions both provides saturation in the glycogen stores and allows the continuity of blood glucose during activity (Maughan, 2002). The deaf athletes stated that they drink water after exercise by 54.3%, have carbohydrate rich meals by 12.9%, eat fruit by 11.4% and drink fruit juice by 10%. In Yarar et al.'s (2011) study on the knowledge and habits of elite level athletes on diets, 27.8% of the athletes stated they do not make any changes in their diets, 27.8% stated that they have carbohydrate rich meals. Since the glycogen re-synthesis speed increases right after competitions or exercise, consuming carbohydrate rich food within the first 2 hours is highly important. Towards the end of competitions, the athlete's performance is negatively affected due to the decrease in the glycogen stores in the liver and blood glucose level (Rodriguez, Dimarco, & Langley, 2009).
It has been seen that 90.3% of the deaf athletes mostly meet their fluid intake with water while doing sports ( Table 6). The findings of Yarar et al.'s study (2011) andYıldırım et al.'s study (2005) support the findings of our study. However, in Bozkurt and Nizamlıoğlu's (2005) study on students who are actively engaged in sports and go to physical education and sports colleges, they students have preferred sugary fruit juice by 62% and water by only 14.4%.
For the optimal performance of athletes, dehydration should be prevented. It can be possible to prevent dehydration by encouraging athletes to adopt the habit of drinking fluids in sufficient and appropriate amounts prior to, during and after exercise or competitions. Therefore, performance loss which can arise due to dehydration can be prevented as well.
Dehydration causes a decrease in the maximal oxygen consumption, an increase in body temperature and loss of coordination (Fink & Mikesky, 2017).
Food which contains carbohydrates and electrolytes are beneficial in both preventing the decrease of blood glucose and the emptying of muscle glycogen stores and providing hydration. During competitions, meeting the fluid need with drinks containing carbohydrates helps in the prevention of mental and physical fatigue (Eskici, 2015). There are studies which have shown that athletes who have drinks containing carbohydrates are more successful compared to athletes who only have water (Ostojic & Mazic, 2002).
While 41.7% of the deaf athletes in the present study stated that they drink 3-4 liters of water each day, 37.5% 1-2 liters, 13.9% 0.5-1 liters and 6.9% 5 liters and more (Table 6), however when compared with the studies carried out individuals with no hearing impairments, these results display differences (Yarar et al., 2011;Göral et al., 2010). The performance of an individual is affected by dehydration even at a low rate of 1% of his body weight. Fluid loss which is over 5% of body weight can lower the productivity of exercise up to 30%. The National Athletic Trainers Association (NATA) has stated that, athletes need to drink about 2-3 glasses of water or sports drinks 2-3 hours before exercise or competitions, 1-2 glasses of water 10-20 minutes before exercise or competitions and 1-2 glasses of water every 10-15 minutes during competitions (Doane, 2016).
Although most of the athletes in our study have stated that honey and molasses are the nutrients which increase their physical activity (Table 7), it has been seen that different results have been indicated in different studies (Yarar et al., 2011).
When the answers related to questions about DSP, their effects and use are analyzed, it can be seen that 81.4% of the participants stated that supplementary vitamin and mineral use is absolutely necessary and that vitamins provide energy to the body; 49.3% stated that an unnecessary amount of vitamins and minerals would be harmful; 48.5% stated that they have information about the use of multivitamins; 52.2% stated that all herbal products are harmless and 57.7% stated that they think that it is necessary to use additional protein supplements in order to increase muscle volume. The athletes need more energy in comparison to sedentary individuals. Depending on the increase of energy need, there is an increase in vitamin and mineral need as well. When athletes have inadequate nutrition, vitamins and minerals can be insufficient; therefore, multivitamin/mineral supplement support can be used. Antioxidant vitamins, especially A, E and C vitamins are quite efficient on performance (Eskici, 2015); however 68.6% of the participants have stated that antioxidants have no effect on the immunity system. More than half of the participants have stated that there is no need to consult a doctor to use DSP and that the dosage is not important. On the contrary, DSP should be used after a detailed evaluation in terms of efficiency, reliability, usefulness and legality. In cases where these products are necessary, the use of right products at the right time and in the right amount is helpful in increasing performance. To be able to achieve this, a decision should be made by getting professional help (Ersoy et al., 2016:130).
As a result, it has been determined in this study that although a majority of deaf athletes are national athletes, they do not have information in general about athlete diets and use of dietary supplement products. There is a need to inform athletes about the issue and carry out individual evaluations; it may be suggested that difficulties deaf athletes and deaf individuals in general experience in accessing the related sources, for instance linguistic and expert personnel to be solved. Counseling should be provided to deaf athletes who actively participate in sports by sports dieticians in issues such as, sufficient and balanced diets, the effect of diets on performance, the importance of drinking fluids and ergogenic support.