Always warm up and cool down properly.
Use proper form to avoid injuries and maximize gains. You can learn good form through a class or one-on-one sessions with a certified exercise professional.
Breathe out when you are lifting or pushing; breathe in as you slowly release the load or weight. Never hold your breath while straining. This action, called the Valsalva maneuver, can temporarily raise your blood pressure considerably and can be risky for people with cardiovascular disease.
Don't lock your joints; always leave a slight bend in your knees and elbows when straightening out your legs and arms.
Don't be so eager to see results that you risk hurting yourself by exercising too long or choosing too much weight. And remember that it's important to rest muscles for at least 48 hours between strength training sessions.
If you've been sick, give yourself one or two days off after recovering. If you were ill for a while, you may need to use lighter weights or less resistance when you first resume exercising.
Strength training exercises should not cause pain while you are doing them. If an exercise or movement causes significant pain, stop doing it! When performing an exercise, stick with a range of motion that feels comfortable. Over time, try to gradually extend that range.
Listen to your body and cut back if you aren't able to finish a series of exercises or an exercise session, can't talk while exercising, feel faint after a session, feel tired during the day, or suffer joint aches and pains after a session.
Healthbeat, January 31, 2015