Ergogenic aids consumption among athletes practicing team sports depending on gender and sense of general self efficacy

Gacek Probl Hig M. Epidemiol Ergogenic 2016, aids consumption 97(2): 177-181 among athletes practicing team sports depending on gender and sense... 177 Ergogenic aids consumption among athletes practicing team sports depending on gender and sense of general self efficacy Częstość spożywania środków ergogenicznych w grupie sportowców dyscyplin zespołowych w zależności od płci i poczucia własnej uogólnionej skuteczności Maria Gacek Zakład Medycyny Sportowej i Żywienia Człowieka, Akademia Wychowania Fizycznego w Krakowie Wprowadzenie. Pokryciu zwiększonych potrzeb żywieniowych sportowców powinna służyć różnorodna i zbilansowana dieta, a jej uzupełnieniem mogą być także żywieniowe środki wspomagające. Jednym z czynników warunkujących zachowania żywieniowe są cechy osobowości związane z przekonaniami i oczekiwaniami zdrowotnymi. Cel. Ocena zależności między płcią i poczuciem własnej uogólnionej skuteczności a przyjmowaniem żywieniowych środków wspomagających przez sportowców. Materiały i metody. Badania przeprowadzono w grupie 320 zawodników wyczynowo trenujących gry zespołowe (103 kobiet i 217 mężczyzn), w wieku 19-36 lat (23,72±4,02). Przyjmowanie żywieniowych środków wspomagających oceniono w skali 3-punktowej, w kategoriach: zawsze (3), okresowo (2) i nigdy (1), za pomocą specjalnie przygotowanego kwestionariusza. Do pomiaru poczucia własnej skuteczności wykorzystano standaryzowaną Skalę Uogólnionej Własnej Skuteczności (GSES), R. Schwarzera i współautorów. Analizę wyników przeprowadzono za pomocą testu t-studenta. Wyniki. Wykazano, że sportowcy spożywali środki wspomagające zazwyczaj okresowo (68% kobiet i 73% mężczyzn), najczęściej przyjmując: napoje izotoniczne, preparaty witaminowe i multimineralne. Kobiety istotnie częściej spożywały preparaty multimineralne (p<0,01), napoje izotoniczne (p<0,05), batony węglowodanowo-białkowe i białkowe (p<0,01), aminokwasy o rozgałęzionych łańcuchach BCAA (p<0,05), L-karnitynę (p<0,01), kwasy tłuszczowe omega-3 (p<0,01), błonnik (p<0,01) oraz kofeinę (p<0,01), a mężczyźni istotnie częściej odżywki białkowe (p<0,01). Wykazano także, że kreatynę istotnie częściej przyjmowali sportowcy o niskim poziomie własnej uogólnionej skuteczności (p<0,01). Wnioski. Wykazane zazwyczaj okresowe przyjmowanie żywieniowych środków wspomagających, najczęściej w postaci napojów izotonicznych oraz witamin i składników mineralnych, było zróżnicowane w zależności od płci oraz poczucia własnej uogólnionej skuteczności zawodników. Introduction. Increased nutritional demands of athletes should be covered with a varied well-balanced diet, supported by ergogenic aids. Personality traits associated with one s health beliefs and expectations constitute a determinant of health behaviors. Aim. To analyze the effect of gender and general self-efficacy on ergogenic aids use among athletes. Material & Method. The study included 320 team sports players (103 women and 217 men), aged between 19 and 36 years (23.72±4.02). The frequency of ergogenic aids use was assessed on a 3-item scale: always (3), periodically (2) and never (1). The sense of self-efficacy was determined with the General Self-Efficacy Scale (GSES) by R. Schwarzer, et al. The results were analyzed with t-student test. Results. Most of the studied athletes (68% of women and 73% of men) periodically used ergogenic aids, mostly isotonic drinks, vitamin and mineral preparations. The women took mineral supplements (p<0.01), isotonic drinks (p<0.05), carbohydrate-protein and protein bars (p<0.01), branched chain amino acids BCAA (p<0.05), L-carnitine (p<0.01), omega-3 fatty acids (p<0.01), dietary fiber (p<0.01) and caffeine (p<0.01) significantly more frequently than men, and male athletes predominated over females in terms of protein supplement use (p<0.01). Moreover, we showed that creatine was significantly more often used by athletes with lower general self-efficacy scores (p<0.01). Conclusion. Usually periodical use of dietary supplements, most often isotonic drinks, vitamins and minerals, was determined by athletes gender and general self-efficacy level. Key words: ergogenic substances, consumption frequency, sportsmen, general self-efficacy Słowa kluczowe: środki erogeniczne, częstość spożycia, sportowcy, poczucie własnej uogólnionej skuteczności Probl Hig Epidemiol 2016, 97(2): 177-181 www.phie.pl Nadesłano: 29.12.2015 Zakwalifikowano do druku: 30.05.2016 Introduction Increased nutritional requirements associated with enhanced metabolism and oxidative stress of athletes should be covered by a varied and well-balanced diet Adres do korespondencji / Address for correspondence dr hab. Maria Gacek Zakład Medycyny Sportowej i Żywienia Człowieka Akademia Wychowania Fizycznego w Krakowie ul. Jana Pawła II 78, 31-571 Kraków tel. 12 683 11 45, e-mail: maria.gacek@awf.krakow.pl providing appropriate amount of energetic, structural and regulatory compounds. Greater demand for protein, especially in speed/strength and strength sports,

178 Probl Hig Epidemiol 2016, 97(2): 177-181 and carbohydrates, particularly in endurance disciplines, is associated with increased requirements for vitamin B complex, antioxidants and certain minerals. Also, adequate hydration deserves special attention, as it is an important determinant of exercise abilities [1-3]. Moreover, a rational diet can include supplements stimulating production of energy, development of muscle mass and strength, and improving physical capacity [3]. According to the classifications of the Medical Commission of the International Olympic Committee [4], and the Australian Institute of Sport [1], sodium bicarbonate, caffeine and creatine are supplements with established efficacy. Furthermore, caffeine, creatine, isotonic drinks, proteins and carbohydrates are recommended as supplements by the Medical Commission of the Polish Olympic Committee [5]. Other compounds are classified as substances with limited or unverified efficacy [4, 5]. Also, the Australian Institute of Sports listed isotonic drinks, liquid meals, sports gels and bars, antioxidants, zinc with vitamin C, multivitamin and mineral supplements, including iron and calcium, glycerol and glucosamine among supplements with established efficacy [1]. Due to its buffering properties, supplementation with sodium bicarbonate can be efficient in strength/endurance and speed/endurance disciplines [6, 7]. Caffeine acts on the central nervous system and prevents fatigue [8], and creatine promotes muscle mass and strength gain, and improves physical capacity [9, 10]. Health-oriented behaviors, including nutritional behaviors, are determined by a wide spectrum of socioeconomic, cultural and personality-related factors [11]. One of the individual traits determining the health culture of a person is the sense of general self-efficacy. The sense of self-efficacy, as an optimistic belief in the ability to achieve goals, allows one to predict his/her intentions and activities in various spheres, including health-oriented and nutritional behaviors [12]. Therefore, we undertook a study on the role of self-efficacy as a predictor of using ergogenic aids by a group of Polish athletes. This constitutes a new aspect of research on psychological determinants of dietary supplementation among athletes. The majority of available literature concerns the nature and motives of the use of dietary supplements by athletes [13-23]. Aim To analyze the effect of gender and general self-efficacy as important individually-specific determinants of ergogenic aids use by Polish athletes practicing team sports on a competitive basis. Material and method The study was conducted between 2011 and 2014, in a group of 320 athletes practicing team sports on a competitive basis, 103 women and 217 men, aged between 19 and 36 years (23.72±4.02). The group was predominated by handball (29%), soccer (27%) and volleyball players (26%), followed by basketball (8%) and ice hockey players (9%). The volleyball (43%) and handball players (37%) predominated among female participants, whereas most of the males practiced soccer (39%), handball (25%), volleyball (18%) and ice hockey (11%). The frequency of ergogenic aids use was assessed on a 3-item scale: always (3), periodically (2) and never (1), included in a survey prepared exclusively for the purpose of this study. The sense of self-efficacy was determined with the General Self-Efficacy Scale (GSES) by R. Schwarzer, M. Jerusalem and Z. Juczyński [12]. The scale includes 10 statements that are scored in such way that the higher the global GSES score (ranging from 10 to 40 points), the stronger the sense of self-efficacy. Based on the median of the raw GSES score for our sample (Me: 31) we classified the participants as presenting lower and higher levels of self-efficacy. The statistical analysis was conducted with PQStat ver. 1.6. software. The results were compared with t-student test. The test probability was considered significant at p<0.05 and highly significant at p<0.01. Results Most of the studied athletes (68% of women and 73% of men) periodically used ergogenic aids. Continuous use of supplements was declared by 32% of female and 21% of male athletes, and only 6% of men did not use them at all. Isotonic drinks, vitamin and mineral supplements turned out to be the most frequently used supplements in our group. In contrast, most the respondents did not use HMB, sodium bicarbonate, MCT, CLA and ginseng preparations (Table 1). The comparative analysis showed that female athletes used ergogenic substances of any type significantly more often than men (p<0.01). The detailed analysis revealed that women took mineral supplements (p<0.01), isotonic drinks (p<0.05), carbohydrate-protein and protein bars (p<0.01), branched chain amino acids BCAA (p<0.05), L-carnitine (p<0.01), omega-3 fatty acids (p<0.01), dietary fiber (p<0.01) and caffeine (p<0.01) significantly more frequently than men, and male athletes predominated over females in terms of protein supplement use (p<0.01) (Table 1). Moreover, athletes with lower self-efficacy levels were shown to use creatine significantly more often that those with stronger sense of general self-efficacy (p<0.01). The intake of other ergogenic substances was not associated with general self-efficacy level presented by team sports athletes (p>0.05) (Table 1).

Gacek M. Ergogenic aids consumption among athletes practicing team sports depending on gender and sense... 179 Table I. Frequency of use of ergogenic aids among athletes, stratified according to gender and level of general self-efficacy (determined on GSES) Tabela I. Częstość stosowania środków erogenicznych wśród sportowców w zależności od płci i poczucia własnej uogólnionej skuteczności (w skali GSES) Analyzed parameters used supplements /Analizowane wskaźniki stosowane suplementy Overall /Ogół Gender /Płeć Level of general self-efficacy (GSES) /Poziom uogólnionej skuteczności (GSES) Low /Niski High /Wysoki p Women /Kobiety Men /Mężczyźni p X±SD X±SD X±SD X±SD X±SD Supplement use /Stosowanie suplementów 2.24±0.49 2.32±0.48 2.16±0.50 0.000 2.24±0.46 2.23±0.52 0.737 Multivitamin supplements /Preparaty witaminowe 2.10±0.63 2.10±0.61 2.10±0.66 0.916 2.10±0.59 2.10±0.68 0.939 Mineral supplements /Preparaty mineralne 2.08±0.65 2.16±0.61 2.01±0.68 0.006 2.10±0.63 2.07±0.68 0.548 Protein supplements /Odżywki białkowe 1.48±0.60 1.33±0.47 1.62±0.66 0.000 1.46±0.57 1.50±0.62 0.397 Carbohydrate supplements /Odżywki węglowodanowe 1.67±0.69 1.71±0.74 1.63±0.64 0.228 1.66±0.66 1.67±0.72 0.815 Protein-carbohydrate supplements 1.45±0.60 1.43±0.62 1.46±0.58 0.545 1.43±0.58 1.47±0.62 0.491 /Odżywki węglowodanowo-białkowe Isotonic drinks /Napoje izotoniczne 2.15±0.73 2.22±0.71 2.08±0.74 0.036 2.14±0.70 2.15±0.75 0.945 Carbohydrate-protein bars 1.35±0.53 1.45±0.59 1.25±0.46 0.000 1.34±0.52 1.36±0.55 0.601 /Batony węglowodanowo-białkowe Carbohydrate bars /Batony węglowodanowe 1.44±0.59 1.56±0.64 1.33±0.52 0.000 1.43±0.58 1.45±0.60 0.742 BCAAs /Aminokwasy BCAA 1.57±0.70 1.65±0.74 1.50±0.66 0.021 1.58±0.68 1.63±0.72 0.054 Creatine /Kreatyna 1.42±0.57 1.43±0.58 1.41±0.56 0.629 1.48±0.61 1.35±0.53 0.009 L-carnitine /L-karnityna 1.29±0.47 1.41±0.49 1.18±0.41 0.000 1.25±0.46 1.33±0.47 0.056 HMB /HMB 1.19±0.43 1.19±0.45 1.18±0.41 0.776 1.19±0.42 1.18±0.44 0.698 Omega-3 fatty acids /Kwasy tłuszczowe omega-3 1.35±0.57 1.44±0.61 1.27±0.51 0.000 1.36±0.57 1.34±0.57 0.777 Dietary fiber /Błonnik pokarmowy 1.42±0.58 1.65±0.63 1.21±0.44 0.000 1.40±0.59 1.45±0.57 0.387 Caffeine /Kofeina 1.72±0.70 1.85±0.69 1.61±0.68 0.000 1.78±0.68 1.67±0.71 0.074 CLA (Conjugated Linoleic Acid) 1.10±0.30 1.12±0.33 1.09±0.28 0.216 1.12±0.32 1.09±0.29 0.318 /CLA (Sprzężony kwas linolowy) Sodium bicarbonate /Dwuwęglan sodu 1.06±0.24 1.06±0.24 1.07±0.25 0.713 1.08±0.27 1.05±0.21 0.108 MCTs (Medium-chain Triglycerides) 1.05±0.22 1.05±0.21 1.06±0.23 0.661 1.06±0.23 1.05±0.21 0.561 /Średniołańcuchowe kwasy tłuszczowe (MCT) Ginseng /Żeńszeń 1.13±0.37 1.13±0.37 1.14±0.37 0.906 1.15±0.39 1.12±0.36 0.296 Discussion Our study revealed a wide use of ergogenic aids among athletes practicing team sports on a competitive basis; however, these substances were ingested periodically rather than continuously. We did observe that the frequency of ingestion differed depending on the supplement type, and was the highest for isotonic drinks and vitamin and mineral supplements. Furthermore, we revealed that the average frequency of some ergogenic substance use was determined by gender and the athletes levels of self-efficacy. Periodic use of supplements was declared by more than 2/3 of athletes taking part in our study. Also the results of studies conducted in foreign centers confirmed frequent use of ergogenic substances by various groups of athletes, e.g. from Australia (87%) [13], Canada (88%) [14, 15], Iran (67%) [16] and other countries [17-20], and showed that the intake of supplements was determined by gender and age [16]. The high prevalence of ergogenics was also described in other groups of Polish athletes [21-23]. The frequent intake of isotonic drinks, the most prevalent ergogenic substances in our group of athletes, is justified by their role in appropriate hydration of body, maintenance of water-electrolyte and acid-base balance during physical exercise and stimulation of post-exercise recovery of glycogen reserves [1, 24, 25]. Equally frequent use of vitamin and mineral supplements in our group reflected an important role of these regulatory compounds in the athletes diet [1]. The vitamin B complex catalyzes metabolic processes associated with the regeneration of structural proteins and glycogen reserves, and the synthesis of energy, thus determining appropriate psychophysical capacities [1, 26]. In turn, the antioxidant vitamins increase antioxidative potential of cells and protect them against the consequences of enhanced oxidative stress resulting from peroxidation of lipids, especially in athletes who practice endurance disciplines [1, 2]. The role of minerals is associated with their involvement in regulation of water-electrolyte and acid-base balance, neuromuscular excitability and hematopoiesis [1, 2]. Practicing sports is associated with an increased demand for some vitamins and minerals which play an important role during strenuous physical exercise, due to their specific functional properties. Therefore, deficiencies of some regulatory compounds, such as calcium [27, 28], iron [29], magnesium [28] and some vitamins of B complex [27, 30] documented in athletes practicing team sports point to the necessity of periodic dietary supplementation with vitamin and mineral supplements. Fortunately, the results of recently published studies suggest that vitamins and minerals belong to the most frequently used supple-

180 Probl Hig Epidemiol 2016, 97(2): 177-181 ments among athletes [16, 31]. Apart from vitamins and minerals, our athletes periodically used caffeine, carbohydrate supplements and BCAA. The use of caffeine, a stimulant that modulates psychophysical capacities, should be interpreted as a positive finding in view of its documented efficacy [8]. Also the use of carbohydrate supplements, as well as carbohydrate-protein and carbohydrate bars, seems justified in view of the involvement of carbohydrates in the energetic processes, post-exercise recovery of glycogen reserves and improvement of exercise capacity, especially during prolonged training sessions [32]. However, a relatively low frequency of using these supplements among our athletes may point to their limited knowledge on dietary support of physical exercise. This hypothesis is supported by the results of some previous studies documenting lower participation of carbohydrates in dietary energy intake of athletes [33]. The research shows that amino acids play an important role in supporting exercise capacity [34-36].The observation that our athletes relatively often used amino acids as ergogenic substances is consistent with the results published by other authors [16]. We observed that women used ergogenic aids significantly more often than male athletes; furthermore, we identified some gender-specific differences in the average frequency of using specific ergogenic substances. Regarding the most popular supplements (i.e. those used periodically), our analysis revealed a more frequent intake of mineral supplements and isotonic drinks among women. This suggests that female athletes pay more attention to substances supporting post-exercise restoration of homeostasis. Protein supplements were used less often, more frequently by men than women, which corresponds to a greater demand for protein in the former [1]. Gender-related differences in the frequency of ergogenic substance use were also documented in a group of physically active Iranians. That study revealed a more frequent use of creatine and amino acids among men and a higher intake of iron supplement by female participants [16]. A more frequent intake of supplements rich in protein, amino acids and carbohydrates among men and supplements containing natural plant-derived compounds and vitamin-mineral supplements among women was in turn documented in a group of gymnasts [18]. Our research confirmed that general self-efficacy is a predictor of some ergogenic substance use. Athletes with a weaker sense of self-efficacy significantly more often used creatine, an ergogenic substance with established efficiency. Also in another Polish study, including a group of American football players, the athletes with lower levels of self-efficacy were shown to take multivitamin preparations significantly more often than those with higher levels of this trait (76 vs. 55%; p<0.05) [37]. This paper adds to our knowledge on the predictive role of personality traits as a determinant of dietary behaviors in various populations. The fact that athletes with a lower level of self-efficacy significantly more often used some ergogenic substances can be interpreted as an attempt to improve nutritional value of their diet, especially that in previous studies individuals with a weak sense of self-efficacy were shown to be generally less prone to rational dietary choices. This phenomenon was observed both among athletes [38, 39] and in other populations [40-46]. Rational diet and supplementation of athletes need to be monitored and adjusted for their personality traits, including general self-efficacy. 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