1- Stretching and weight training are physical ergogenic aids. Stretching helps prevent muscle cramping while weight training increases strength.
2- Visualization and hypnosis are mental ergogenic aids. These aids help reduce anxiety and thus improve athletic performance.
3- Lighter weight running shoes and better designed golf clubs are mechanical ergogenic aids. Mechanical ergogenic aids don't necessarily improve athletic performance, as they are similar to placebo.
4- The most commonly recognized form of ergogenic aids is the dietary supplement. For example, supplemental creatine is a popular ergogenic aid, but its benefits are limited. Research has shown creatine to be effective in increasing muscle strength and power during brief, high intensity exercise lasting about one minute or less (such as sprinting and weight lifting).Creatine will not benefit endurance athletes. A common side effect is weight gain, which can make athletes feel sluggish. Other reported side effects include diarrhea, muscle cramps, and dehydration.
Hope I helped!
