Men's testicles shrink, the prostate gland enlarges, and sperm levels drop. Behavior changes may include aggression, paranoia, mood swings, low sex drive, and depression. Blood doping is another ergogenic aid that is dangerous. Giving blood or blood products to an athlete to improve endurance and speed can have harmful side effects, such as strokes, allergic reactions, and infections. Human growth hormone is a widely abused ergogenic aid by body builders.
Some body builders take large doses to decrease fat and increase muscle mass.
The side effects are heart and nerve diseases, glucose intolerance, and higher levels of blood fats. Caffeine affects the central nervous system by increasing mental alertness and reducing fatigue. If over-used, it can cause irritability, restlessness, diarrhea, insomnia, and anxiety. It is found in coffee, tea, chocolate, and soft drinks. If you want to improve your sports performance, use only ergogenic aids that are legal, healthy, and have been proven safe.