Lets focus on the role that negative repetitions have to play in intensifying the training effect.At the most basic level, human muscles have three types of strength:
1. Positive strength – the ability to raise a weight.
2. Static strength – the ability to hold a weight.
3. Negative strength – the ability to lower a weight.
Many bodybuilders concentrate primarily on their muscles’ positive and static strength but equal focus should be given to negative strength, or lowering the weight, if true muscle failure is to be achieved.
You’ll need one or two partners to lift the weight to the top position so that you can lower it under your own control. Once you can no longer control the descent, the set ends. Take special care with leg exercises and avoid negative squats to protect the knees. Beginners should not attempt negative reps while intermediate and advanced bodybuilders can be imaginative in how they incorporate negative reps into their training programs.