the work is retrospective. Most athletes use supplements to bolster their dietary intake, everything from everyday vitamins such as magnesium and iron plus products such as whey protein, creatine, carnitine and branched-chain amino acids -LRB- BCAAs -RRB- specifically aimed at improving performance and recovery. But, with drug-testing standards improving year by year and the list of banned substances also increasing, there is a strong onus for athletes to be acutely aware of everything they put in their mouth. Most athletes are using quite a few supplements. They live an extreme life, the amount of training they do is extreme, they exercise way outside what the normal person would do, so it is important to supplement their diet, Corones says. There is a very fine line and it's something that athletes need to stay on top of. The onus is 100 % on the athlete and we make that very clear to them from a young age that they are responsible for what goes in their mouth. No matter if it comes from their coach or their parents or their brother or their friend, they have to know what they 're putting in their body. You might trust your coach 100 % but if he gives you a bottle of tablets and tells you it's iron, it's still your responsibility to get that checked. We have hotlines where the athletes can call up and check anything, so it's pretty easy to find out if it's okay to take.