You can only build muscle tissue if you can generate progressively stronger muscular contractions, so this calls for an emphasis on finding ways to increase exercise intensity. This should not be confused with exercise duration as maximum training intensity will actually shorten the time needed to achieve maximal muscular growth.

In an earlier article I outlined the ways in which you can intensify your training. Here we'll 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 can emphasize this aspect of training by completing a set of negative reps after reaching positive failure.

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.

Richard Mitchell is the creator of the bodybuildingadvisor.com website that provides guidance and information to athletes at all levels of bodybuilding experience. Go to Bodybuilding Advice to learn more about the issues covered in this article.