Competing in professional sports means that you are held to higher standards. Part of these standards involves not using various substances in an effort to achieve greater levels of performance. But how do you know whether or not a supplement is okay for your sport of choice?The U.K. Anti-Doping WebsitePerhaps the easiest way to know for sure, and to know that the information that you are receiving is current, is to check the U.K. Anti-Doping Website. On it they have a bunch of different resources that you can view, some that you can even download, that share what substances can and cannot be used in your particular sport. They even provide advice depending on whether you are a beginner athlete or an elite, and everything in between.One of these such resources is The Prohibited List 2015. This is the World Anti-Doping Code and it outlines the various steroids, anabolic agents, hormones, growth factors, stimulants, narcotics, diuretics, and masking agents that are prohibited (some of them at certain times and some at all times), as well as the methods of administration that are barred as well.It also lists the substances that are prohibited based on the sport you are in and whether you are in or out of competition. For instance, alcohol is prohibited in competition only for air sports, archery, and motorcycling, amongst others. Also, beta-blockers are prohibited in competition for billiards, darts, and golf, but they are also prohibited in and out of competition in archery and shooting.Your Trainers Another way to find out whether or not a supplement is okay for your sport is to talk to your trainers or mentors. As such, they should know the rules for your sport, which puts them in a good position to tell you what you can and cannot take in an effort to improve your performance.