Background Supplement use is common in sport. Burns (2004), reported that 88.0% of the questions athletes used at least one supplements and 58% admitted using more than one type.¹ Besides their cost, use of supplements may have side effects on general health and sports performance. Nobody cannot ignore role of coach in athletes sport achievement. Fung and Juan (2006) found there was a large discrepancy between coaches' perceived knowledge and actual knowledge.²

Methods This studies utilized a cross-sectional survey design and cluster sampling. 95 validated questionnaires were distributed among national team coaches in 30 different fields of sports. A questionnaire designed to explore coaches' attitude to supplement consumption by athletes, beliefs and knowledge regarding dietary supplements. Mean age of participants was 36 years.

Results The knowledge of coaches about supplements was good in 42.3%, fair in 51.2%, and poor in 6.5%; whilst 74.6% felt that they have little knowledge and 83.7% were eager to learn more about supplements' effects on general health, performance enhancing properties and potential negative side effects. 68.3% stated that supplements are unavoidable part of competitive sports. They thought over than 80% of elite athletes use supplements. They revealed 19% experience of inadvertent doping due to supplement contamination with prohibited substances. They expressed athletes like have a recommendation of sport supplements use by nutritionists (32.4%), medical doctors (26.1%), coaches (20%), fitness trainers (12.6%) and pharmacists (8.9%). They cited athletes using supplements based on recommendation (48.6%), brand (31.3%), advertising claims (21%), availability (18%) and price (12%).

Discussion Our study revealed that many coaches mentioned that athletes should acquire information from nutritionists, medical doctors, coaches, fitness trainers and pharmacists. Consistent with our research, Malinauskas et al. in their study found that 71% of athletes considered coaches the best consultants regarding sports supplements.³ It is evident that coaches can be a reliable information source if they improve their knowledge. So that, sport organizations can schedule educational sessions for coaches to develop their nutrition and supplement information. Subsequently they can transfer the information to athletes for best practice.