How heavy should you go?

Only lift as heavy weights as you can still keep good form with whilst lifting, unless you are training the “cheat set” way then you can go much heavier but for most people this shouldn’t be the case.  The whole point of not lifting heavier than what you can keep good form with is so that you don’t injure your self and you ensure great isolation of the muscle group you are trying to work out.  If you are doing bicep curls and the weight is too heavy you will naturally swing your back to lift the weight, this will work the back not the bicep which you are trying to isolate.  Below I have listed common movements people make when trying to lift heavy weights that reduces the isolation process.

• Swinging back in bicep curls – works out back and less the biceps – Read how to do the “perfect bicep curl” for more info.
• Shoulder press doing mini squats to lift weight – works out legs and less on the shoulders
• Bench press pushing up with shoulders – works out shoulders and triceps more than chest.  Most people do this you need to really think about isolating the chest and pushing the chest through out the whole movement as the shoulders and triceps easily take over.  Read 10 ways to improve your bench press for more info.
• Lat flyes swinging the body and not getting to the top of the rep- works out traps a lot more than the side of the deltoids.

Related articles -

101 ways to build muscle