Bodybuilding is a very safe activity, but it's possible to injure yourself if you don't follow these rules:

1. Use Spotters. This is particularly important when you have entered the advanced stages of bodybuilding and are handling very heavy poundages in such exercises as the bench press and the squat. A spotter can help you by lifting a barbell off your body when you get stuck at the bottom of a movement.
2. Use catch racks if spotters aren't available.
3. Use collars on your barbell at all times.
4. Never hold your breath. Holding your breath can cause you to black out.
5. Maintain good gym housekeeping. It's easy to trip over loose weights.
6. Don't train in an overcrowded gym.
7. Always warm up thoroughly before every workout.
8. Use proper training form in all exercises.
9. Use a weightlifting belt when handling heavy weights.
10. Don't allow yourself to be goaded into trying more weight than you're capable of lifting.
11. Acquire as much knowledge as possible about weight training.